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1.
Chembiochem ; : e202400292, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38970452

RESUMO

Streptonigrin (STN, 1) is a highly functionalized aminoquinone alkaloid antibiotic with broad and potent antitumor activity. STN structurally contains four methyl groups belonging to two types: C-methyl group and O-methyl groups. Here, we report the biochemical characterization of the O-methyltransferase StnQ2 that can catalyze both the methylation of a hydroxyl group and a carboxyl group in the biosynthesis of streptonigrin. This work not only provides a new insight into methyltransferases, but also advances the elucidation of the complete biosynthetic pathway of streptonigrin.

2.
Front Microbiol ; 15: 1415554, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952446

RESUMO

Introduction: The unique dormancy of Mycobacterium tuberculosis plays a significant role in the major clinical treatment challenge of tuberculosis, such as its long treatment cycle, antibiotic resistance, immune escape, and high latent infection rate. Methods: To determine the function of MtrA, the only essential response regulator, one strategy was developed to establish its regulatory network according to high-quality genome-wide binding sites. Results and discussion: The complex modulation mechanisms were implied by the strong bias distribution of MtrA binding sites in the noncoding regions, and 32.7% of the binding sites were located inside the target genes. The functions of 288 potential MtrA target genes predicted according to 294 confirmed binding sites were highly diverse, and DNA replication and damage repair, lipid metabolism, cell wall component biosynthesis, cell wall assembly, and cell division were the predominant pathways. Among the 53 pathways shared between dormancy/resuscitation and persistence, which accounted for 81.5% and 93.0% of the total number of pathways, respectively, MtrA regulatory genes were identified not only in 73.6% of their mutual pathways, but also in 75.4% of the pathways related to dormancy/resuscitation and persistence respectively. These results suggested the pivotal roles of MtrA in regulating dormancy/resuscitation and the apparent relationship between dormancy/resuscitation and persistence. Furthermore, the finding that 32.6% of the MtrA regulons were essential in vivo and/or in vitro for M. tuberculosis provided new insight into its indispensability. The findings mentioned above indicated that MtrA is a novel promising therapeutic target for tuberculosis treatment since the crucial function of MtrA may be a point of weakness for M. tuberculosis.

3.
Nat Commun ; 15(1): 5687, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38971862

RESUMO

Base editing (BE) faces protospacer adjacent motif (PAM) constraints and off-target effects in both eukaryotes and prokaryotes. For Streptomyces, renowned as one of the most prolific bacterial producers of antibiotics, the challenges are more pronounced due to its diverse genomic content and high GC content. Here, we develop a base editor named eSCBE3-NG-Hypa, tailored with both high efficiency and -fidelity for Streptomyces. Of note, eSCBE3-NG-Hypa recognizes NG PAM and exhibits high activity at challenging sites with high GC content or GC motifs, while displaying minimal off-target effects. To illustrate its practicability, we employ eSCBE3-NG-Hypa to achieve precise key amino acid conversion of the dehydratase (DH) domains within the modular polyketide synthase (PKS) responsible for the insecticide avermectins biosynthesis, achieving domains inactivation. The resulting DH-inactivated mutants, while ceasing avermectins production, produce a high yield of oligomycin, indicating competitive relationships among multiple biosynthetic gene clusters (BGCs) in Streptomyces avermitilis. Leveraging this insight, we use eSCBE3-NG-Hypa to introduce premature stop codons into competitor gene cluster of ave in an industrial S. avermitilis, with the mutant Δolm exhibiting the highest 4.45-fold increase in avermectin B1a compared to the control. This work provides a potent tool for modifying biosynthetic pathways and advancing metabolic engineering in Streptomyces.


Assuntos
Sistemas CRISPR-Cas , Citosina , Edição de Genes , Policetídeo Sintases , Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Edição de Genes/métodos , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Citosina/metabolismo , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Oligomicinas
4.
Adv Sci (Weinh) ; : e2404668, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38935027

RESUMO

Polyethers play a crucial role in the development of anticancer drugs. To enhance the anticancer efficacy and reduce the toxicity of these compounds, thereby advancing their application in cancer treatment, herein, guided by the structure-activity relationships of aglycone polyethers, novel aglycone polyethers are rationally redesigned with potentially improved efficacy and reduced toxicity against tumors. To realize the biosynthesis of the novel aglycone polyethers, the gene clusters and the post-polyketide synthase tailoring pathways for aglycone polyethers endusamycin and lenoremycin are identified and subjected to combinatorial biosynthesis studies, resulting in the creation of a novel aglycone polyether termed End-16, which demonstrates significant potential for treating bladder cancer (BLCA). End-16 demonstrates the ability to suppress the proliferation, migration, invasion, and cellular protrusions formation of BLCA cells, as well as induce cell cycle arrest in the G1 phase in vitro. Notably, End-16 exhibits superior inhibitory activity and fewer side effects against BLCA compared to the frontline anti-BLCA drug cisplatin in vivo, thereby warranting further preclinical studies. This study highlights the significant potential of integrating combinatorial biosynthesis strategies with rational design to create unnatural products with enhanced pharmacological properties.

5.
Plant J ; 119(2): 927-941, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38872484

RESUMO

Acteoside is a bioactive phenylethanoid glycoside widely distributed throughout the plant kingdom. Because of its two catechol moieties, acteoside displays a variety of beneficial activities. The biosynthetic pathway of acteoside has been largely elucidated, but the assembly logic of two catechol moieties in acteoside remains unclear. Here, we identified a novel polyphenol oxidase OfPPO2 from Osmanthus fragrans, which could hydroxylate various monophenolic substrates, including tyrosine, tyrosol, tyramine, 4-hydroxyphenylacetaldehyde, salidroside, and osmanthuside A, leading to the formation of corresponding catechol-containing intermediates for acteoside biosynthesis. OfPPO2 could also convert osmanthuside B into acteoside, creating catechol moieties directly via post-modification of the acteoside skeleton. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis and subcellular localization assay further support the involvement of OfPPO2 in acteoside biosynthesis in planta. These findings suggest that the biosynthesis of acteoside in O. fragrans may follow "parallel routes" rather than the conventionally considered linear route. In support of this hypothesis, the glycosyltransferase OfUGT and the acyltransferase OfAT could direct the flux of diphenolic intermediates generated by OfPPO2 into acteoside. Significantly, OfPPO2 and its orthologs constitute a functionally conserved enzyme family that evolved independently from other known biosynthetic enzymes of acteoside, implying that the substrate promiscuity of this PPO family may offer acteoside-producing plants alternative ways to synthesize acteoside. Overall, this work expands our understanding of parallel pathways plants may employ to efficiently synthesize acteoside, a strategy that may contribute to plants' adaptation to environmental challenges.


Assuntos
Catecol Oxidase , Glucosídeos , Fenóis , Proteínas de Plantas , Catecol Oxidase/metabolismo , Catecol Oxidase/genética , Glucosídeos/metabolismo , Glucosídeos/biossíntese , Fenóis/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Vias Biossintéticas , Oleaceae/enzimologia , Oleaceae/genética , Oleaceae/metabolismo , Catecóis/metabolismo , Regulação da Expressão Gênica de Plantas , Polifenóis
6.
PLoS Biol ; 22(5): e3002628, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38814940

RESUMO

The peptidoglycan (PG) layer is a critical component of the bacterial cell wall and serves as an important target for antibiotics in both gram-negative and gram-positive bacteria. The hydrolysis of septal PG (sPG) is a crucial step of bacterial cell division, facilitated by FtsEX through an amidase activation system. In this study, we present the cryo-EM structures of Escherichia coli FtsEX and FtsEX-EnvC in the ATP-bound state at resolutions of 3.05 Å and 3.11 Å, respectively. Our PG degradation assays in E. coli reveal that the ATP-bound conformation of FtsEX activates sPG hydrolysis of EnvC-AmiB, whereas EnvC-AmiB alone exhibits autoinhibition. Structural analyses indicate that ATP binding induces conformational changes in FtsEX-EnvC, leading to significant differences from the apo state. Furthermore, PG degradation assays of AmiB mutants confirm that the regulation of AmiB by FtsEX-EnvC is achieved through the interaction between EnvC-AmiB. These findings not only provide structural insight into the mechanism of sPG hydrolysis and bacterial cell division, but also have implications for the development of novel therapeutics targeting drug-resistant bacteria.


Assuntos
Trifosfato de Adenosina , Divisão Celular , Proteínas de Escherichia coli , Escherichia coli , Peptidoglicano , Peptidoglicano/metabolismo , Hidrólise , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/química , Escherichia coli/metabolismo , Escherichia coli/genética , Trifosfato de Adenosina/metabolismo , Microscopia Crioeletrônica , Parede Celular/metabolismo , Conformação Proteica , Modelos Moleculares , N-Acetil-Muramil-L-Alanina Amidase/metabolismo , N-Acetil-Muramil-L-Alanina Amidase/genética , Proteínas da Membrana Bacteriana Externa , Transportadores de Cassetes de Ligação de ATP , Regulador de Condutância Transmembrana em Fibrose Cística , Lipoproteínas , Proteínas de Ciclo Celular
7.
Synth Syst Biotechnol ; 9(4): 609-617, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38784197

RESUMO

Spinosad, a potent broad-spectrum bioinsecticide produced by Saccharopolyspora spinosa, has significant market potential. Despite its effectiveness, the regulatory mechanisms of spinosad biosynthesis remain unclear. Our investigation identified the crucial role of the LysR family transcriptional regulator ORF-L16, located upstream of spinosad biosynthetic genes, in spinosad biosynthesis. Through reverse transcription PCR (RT-PCR) and 5'-rapid amplification of cDNA ends (5'-Race), we unveiled that the spinosad biosynthetic gene cluster (BGC) contains six transcription units and seven promoters. Electrophoretic mobility shift assays (EMSAs) demonstrated that ORF-L16 bound to seven promoters within the spinosad BGC, indicating its involvement in regulating spinosad biosynthesis. Notably, deletion of ORF-L16 led to a drastic reduction in spinosad production from 1818.73 mg/L to 1.69 mg/L, accompanied by decreased transcription levels of spinosad biosynthetic genes, confirming its positive regulatory function. Additionally, isothermal titration calorimetry (ITC) and EMSA confirmed that spinosyn A, the main product of the spinosad BGC, served as an effector of ORF-L16. Specifically, it decreased the binding affinity between ORF-L16 and spinosad BGC promoters, thus exerting negative feedback regulation on spinosad biosynthesis. This research enhances our comprehension of spinosad biosynthesis regulation and lays the groundwork for future investigations on transcriptional regulators in S. spinosa.

8.
Environ Sci Pollut Res Int ; 31(24): 35595-35608, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38735997

RESUMO

The "dual-carbon" objective presents a huge challenge for China and the world, with profound implications for the advancement of China's eco-friendly economy. Additionally, informatization development has a significant impact on the level of carbon emissions in both local and neighbouring regions. Therefore, we employ panel data from 30 provinces in China spanning the years 2012 to 2021, and use the Kernel density estimate and Moran's index to explore informatization level and carbon emissions space agglomeration characteristics. We elucidate the nonlinear relationship and heterogeneity between informatization improvement and carbon emissions based on the spatial Durbin model. The primary findings are as follows. Firstly, we discover a distinct spatial clustering phenomenon which the informatization level is high in coastal areas and low in inland areas, whereas carbon emissions are low in the south and high in the north. Secondly, the effect of the informatization level on carbon emissions is shown as a U-shaped and non-linear correlation, signifying inhibitory and subsequently promoting phases. Thirdly, we reveal the negative influence on carbon emissions caused by spatial lag terms of the informatization level, and find that a higher local informatization level will have an inhibitory effect on carbon emissions in neighbouring areas. Finally, there is a spatial heterogeneity in the impact of the informatization level on carbon emissions, which presents the U-shaped relation between informatization level and carbon emissions varies across the North-South subregion and the three major economic subregion of China.


Assuntos
Carbono , China , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Poluição do Ar , Análise Espacial
9.
Mar Drugs ; 22(4)2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38667806

RESUMO

Polyene macrolactams are a special group of natural products with great diversity, unique structural features, and a wide range of biological activities. Herein, a cryptic gene cluster for the biosynthesis of putative macrolactams was disclosed from a sponge-associated bacterium, Streptomyces sp. DSS69, by genome mining. Cloning and heterologous expression of the whole biosynthetic gene cluster led to the discovery of weddellamycin, a polyene macrolactam bearing a 23/5/6 ring skeleton. A negative regulator, WdlO, and two positive regulators, WdlA and WdlB, involved in the regulation of weddellamycin production were unraveled. The fermentation titer of weddellamycin was significantly improved by overexpression of wdlA and wdlB and deletion of wdlO. Notably, weddellamycin showed remarkable antibacterial activity against various Gram-positive bacteria including MRSA, with MIC values of 0.10-0.83 µg/mL, and antifungal activity against Candida albicans, with an MIC value of 3.33 µg/mL. Weddellamycin also displayed cytotoxicity against several cancer cell lines, with IC50 values ranging from 2.07 to 11.50 µM.


Assuntos
Antibacterianos , Lactamas Macrocíclicas , Testes de Sensibilidade Microbiana , Família Multigênica , Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Antibacterianos/farmacologia , Antibacterianos/biossíntese , Antibacterianos/química , Humanos , Lactamas Macrocíclicas/farmacologia , Lactamas Macrocíclicas/química , Lactamas Macrocíclicas/isolamento & purificação , Polienos/farmacologia , Polienos/isolamento & purificação , Polienos/química , Candida albicans/efeitos dos fármacos , Linhagem Celular Tumoral , Regiões Antárticas , Animais , Poríferos/microbiologia , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação
10.
J Agric Food Chem ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38597928

RESUMO

Spinosad is a potent insecticide produced by Saccharopolyspora spinosa. However, it harbors certain limitations of a low growing rate and unfeasible genetic manipulation that can be overcome by adopting a superior platform, such as Streptomyces. Herein, we exploited the industrial tylosin-producing Streptomyces fradiae J1-021 for the heterologous production of spinosad. An engineered strain (HW01) with deletion of the tylosin biosynthetic gene cluster (BGC) was constructed and then transformed with the natural spinosad BGC. The distribution and expression levels of the tylosin BGC operons were assessed to construct a natural promoter library. The rate-limiting steps of spinosad biosynthesis were identified by analyzing the transcriptional expression of the spinosad biosynthetic genes. The stepwise engineering work involved the overexpression of the biosynthetic genes participating in rate-limiting pathways using strong promoters, affording an increase in spinosad production to 112.4 µg/L. These results demonstrate that strain HW01 has the potential to be used as a chassis for the heterologous production of polyketides.

11.
mBio ; 15(4): e0003124, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38501868

RESUMO

The Clp protease system is important for maintaining proteostasis in bacteria. It consists of ClpP serine proteases and an AAA+ Clp-ATPase such as ClpC1. The hexameric ATPase ClpC1 utilizes the energy of ATP binding and hydrolysis to engage, unfold, and translocate substrates into the proteolytic chamber of homo- or hetero-tetradecameric ClpP for degradation. The assembly between the hetero-tetradecameric ClpP1P2 chamber and the Clp-ATPases containing tandem ATPase domains from the same species has not been studied in depth. Here, we present cryo-EM structures of the substrate-bound ClpC1:shClpP1P2 from Streptomyces hawaiiensis, and shClpP1P2 in complex with ADEP1, a natural compound produced by S. hawaiiensis and known to cause over-activation and dysregulation of the ClpP proteolytic core chamber. Our structures provide detailed information on the shClpP1-shClpP2, shClpP2-ClpC1, and ADEP1-shClpP1/P2 interactions, reveal conformational transition of ClpC1 during the substrate translocation, and capture a rotational ATP hydrolysis mechanism likely dominated by the D1 ATPase activity of chaperones.IMPORTANCEThe Clp-dependent proteolysis plays an important role in bacterial homeostasis and pathogenesis. The ClpP protease system is an effective drug target for antibacterial therapy. Streptomyces hawaiiensis can produce a class of potent acyldepsipeptide antibiotics such as ADEP1, which could affect the ClpP protease activity. Although S. hawaiiensis hosts one of the most intricate ClpP systems in nature, very little was known about its Clp protease mechanism and the impact of ADEP molecules on ClpP. The significance of our research is in dissecting the functional mechanism of the assembled Clp degradation machinery, as well as the interaction between ADEP1 and the ClpP proteolytic chamber, by solving high-resolution structures of the substrate-bound Clp system in S. hawaiiensis. The findings shed light on our understanding of the Clp-dependent proteolysis in bacteria, which will enhance the development of antimicrobial drugs targeting the Clp protease system, and help fighting against bacterial multidrug resistance.


Assuntos
Adenosina Trifosfatases , Endopeptidase Clp , Streptomyces , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Proteólise , Adenosina Trifosfatases/metabolismo , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Peptídeo Hidrolases/metabolismo , Trifosfato de Adenosina/metabolismo
12.
Plants (Basel) ; 13(4)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38498481

RESUMO

The interplay of various enzymes and compounds gives rise to the intricate secondary metabolic networks observed today. However, the current understanding of their formation and expansion remains limited. BAHD acyltransferases play important roles in the biosynthesis of numerous significant secondary metabolites. In plants, they are widely distributed and exhibit a diverse range of activities. Among them, rosmarinic acid synthase (RAS) and hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) have gained significant recognition and have been extensively investigated as prominent members of the BAHD acyltransferase family. Here, we conducted a comprehensive study on a unique group of RAS homologous enzymes in Mentha longifolia that display both catalytic activities and molecular features similar to HCT and Lamiaceae RAS. Subsequent phylogenetic and comparative genome analyses revealed their derivation from expansion events within the HCT gene family, indicating their potential as collateral branches along the evolutionary trajectory, leading to Lamiaceae RAS while still retaining certain ancestral vestiges. This discovery provides more detailed insights into the evolution from HCT to RAS. Our collective findings indicate that gene duplication is the driving force behind the observed evolutionary pattern in plant-specialized enzymes, which probably originated from ancestral enzyme promiscuity and were subsequently shaped by principles of biological adaptation.

13.
Proc Natl Acad Sci U S A ; 121(11): e2321722121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38446858

RESUMO

Aromatic polyketides are renowned for their wide-ranging pharmaceutical activities. Their structural diversity is mainly produced via modification of limited types of basic frameworks. In this study, we characterized the biosynthesis of a unique basic aromatic framework, phenyldimethylanthrone (PDA) found in (+)/(-)-anthrabenzoxocinones (ABXs) and fasamycin (FAS). Its biosynthesis employs a methyltransferase (Abx(+)M/Abx(-)M/FasT) and an unusual TcmI-like aromatase/cyclase (ARO/CYC, Abx(+)D/Abx(-)D/FasL) as well as a nonessential helper ARO/CYC (Abx(+)C/Abx(-)C/FasD) to catalyze the aromatization/cyclization of polyketide chain, leading to the formation of all four aromatic rings of the PDA framework, including the C9 to C14 ring and a rare angular benzene ring. Biochemical and structural analysis of Abx(+)D reveals a unique loop region, giving rise to its distinct acyl carrier protein-dependent specificity compared to other conventional TcmI-type ARO/CYCs, all of which impose on free molecules. Mutagenic analysis discloses critical residues of Abx(+)D for its catalytic activity and indicates that the size and shape of its interior pocket determine the orientation of aromatization/cyclization. This study unveils the tetracyclic and non-TcmN type C9 to C14 ARO/CYC, significantly expanding our cognition of ARO/CYCs and the biosynthesis of aromatic polyketide framework.


Assuntos
Aromatase , Policetídeos , Ciclização , Proteína de Transporte de Acila , Catálise
14.
Mol Microbiol ; 121(5): 971-983, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38480679

RESUMO

Increasing evidence suggests that DNA phosphorothioate (PT) modification serves several purposes in the bacterial host, and some restriction enzymes specifically target PT-DNA. PT-dependent restriction enzymes (PDREs) bind PT-DNA through their DNA sulfur binding domain (SBD) with dissociation constants (KD) of 5 nM~1 µM. Here, we report that SprMcrA, a PDRE, failed to dissociate from PT-DNA after cleavage due to high binding affinity, resulting in low DNA cleavage efficiency. Expression of SBDs in Escherichia coli cells with PT modification induced a drastic loss of cell viability at 25°C when both DNA strands of a PT site were bound, with one SBD on each DNA strand. However, at this temperature, SBD binding to only one PT DNA strand elicited a severe growth lag rather than lethality. This cell growth inhibition phenotype was alleviated by raising the growth temperature. An in vitro assay mimicking DNA replication and RNA transcription demonstrated that the bound SBD hindered the synthesis of new DNA and RNA when using PT-DNA as the template. Our findings suggest that DNA modification-targeting proteins might regulate cellular processes involved in DNA metabolism in addition to being components of restriction-modification systems and epigenetic readers.


Assuntos
Replicação do DNA , Proteínas de Escherichia coli , Escherichia coli , Enxofre , Escherichia coli/metabolismo , Escherichia coli/genética , Enxofre/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , DNA Bacteriano/metabolismo , Enzimas de Restrição do DNA/metabolismo , Ligação Proteica , DNA/metabolismo , Sítios de Ligação
15.
Trends Mol Med ; 30(5): 420-422, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38453528

RESUMO

In a recent report, Zampaloni et al. describe a novel tethered macrocyclic peptide (MCP) antibiotic, zosurabalpin, that disrupts the essential function of the LptB2FGC complex in Gram-negative bacteria and demonstrates efficacy against carbapenem-resistant Acinetobacter baumannii (CRAB). Its preclinical success suggests a substantial shift in treating antibiotic resistance, pending clinical trials to validate its effectiveness, pharmacokinetics, and resistance management.


Assuntos
Antibacterianos , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Peptídeos Cíclicos/uso terapêutico , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Animais
16.
Metab Eng ; 83: 61-74, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522576

RESUMO

5-Methyluridine (5-MU) is a prominent intermediate for industrial synthesis of several antiviral-drugs, however, its availability over the past decades has overwhelmingly relied on chemical and enzymatic strategies. Here, we have realized efficient production of 5-MU in E. coli, for the first time, via a designer artificial pathway consisting of a two-enzyme cascade (UMP 5-methylase and phosphatase). More importantly, we have engineered the E. coli cell factory to boost 5-MU production by systematic evaluation of multiple strategies, and as a proof of concept, we have further developed an antibiotic-free fermentation strategy to realize 5-MU production (10.71 g/L) in E. coli MB229 (a ΔthyA strain). Remarkably, we have also established a versatile and robust platform with exploitation of the engineered E. coli for efficient production of diversified UMP-derived chemicals. This study paves the way for future engineering of E. coli as a synthetic biology platform for acceleratively accessing UMP-derived chemical diversities.


Assuntos
Escherichia coli , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo
17.
PLoS Biol ; 22(3): e3002528, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38427710

RESUMO

Streptomyces antibiotic regulatory proteins (SARPs) are widely distributed activators of antibiotic biosynthesis. Streptomyces coelicolor AfsR is an SARP regulator with an additional nucleotide-binding oligomerization domain (NOD) and a tetratricopeptide repeat (TPR) domain. Here, we present cryo-electron microscopy (cryo-EM) structures and in vitro assays to demonstrate how the SARP domain activates transcription and how it is modulated by NOD and TPR domains. The structures of transcription initiation complexes (TICs) show that the SARP domain forms a side-by-side dimer to simultaneously engage the afs box overlapping the -35 element and the σHrdB region 4 (R4), resembling a sigma adaptation mechanism. The SARP extensively interacts with the subunits of the RNA polymerase (RNAP) core enzyme including the ß-flap tip helix (FTH), the ß' zinc-binding domain (ZBD), and the highly flexible C-terminal domain of the α subunit (αCTD). Transcription assays of full-length AfsR and truncated proteins reveal the inhibitory effect of NOD and TPR on SARP transcription activation, which can be eliminated by ATP binding. In vitro phosphorylation hardly affects transcription activation of AfsR, but counteracts the disinhibition of ATP binding. Overall, our results present a detailed molecular view of how AfsR serves to activate transcription.


Assuntos
Proteínas de Ligação a DNA , Streptomyces , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Microscopia Crioeletrônica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Antibacterianos , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica
18.
Nat Commun ; 15(1): 2128, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459030

RESUMO

Modulation of protein function through allosteric regulation is central in biology, but biomacromolecular systems involving multiple subunits and ligands may exhibit complex regulatory mechanisms at different levels, which remain poorly understood. Here, we discover an aldo-keto reductase termed AKRtyl and present its three-level regulatory mechanism. Specifically, by combining steady-state and transient kinetics, X-ray crystallography and molecular dynamics simulation, we demonstrate that AKRtyl exhibits a positive synergy mediated by an unusual Monod-Wyman-Changeux (MWC) paradigm of allosteric regulation at low concentrations of the cofactor NADPH, but an inhibitory effect at high concentrations is observed. While the substrate tylosin binds at a remote allosteric site with positive cooperativity. We further reveal that these regulatory mechanisms are conserved in AKR12D subfamily, and that substrate cooperativity is common in AKRs across three kingdoms of life. This work provides an intriguing example for understanding complex allosteric regulatory networks.


Assuntos
Proteínas , Aldo-Ceto Redutases/genética , Aldo-Ceto Redutases/metabolismo , Sítio Alostérico , Regulação Alostérica , NADP/metabolismo , Cinética
19.
J Psychiatr Res ; 172: 119-128, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38377667

RESUMO

This study aimed to identify neural biomarkers for schizophrenia (SZ) and bipolar disorder (BP) by analyzing multimodal neuroimaging. Utilizing data from structural magnetic resonance imaging (sMRI), diffusion tensor imaging (DTI), and resting-state functional magnetic resonance imaging (rs-fMRI), multiclass classification models were created for SZ, BP, and healthy controls (HC). A total of 113 participants (BP: 31, SZ: 39, and HC: 43) were recruited under strict enrollment control, from which 272, 200, and 1875 features were extracted from sMRI, DTI, and rs-fMRI data, respectively. A support vector machine (SVM) with recursive feature elimination (RFE) was employed to build the models using a one-against-one approach and leave-one-out cross-validation, achieving a classification accuracy of 70.8%. The most discriminative features were primarily from rs-fMRI, along with significant findings in sMRI and DTI. Key biomarkers identified included the increased thickness of the left cuneus cortex and decreased regional functional connectivity strength (rFCS) in the left supramarginal gyrus as shared indicators for BP and SZ. Additionally, decreased fractional anisotropy in the left superior fronto-occipital fasciculus was suggested as specific to BP, while decreased rFCS in the left inferior parietal area might serve as a specific biomarker for SZ. These findings underscore the potential of multimodal neuroimaging in distinguishing between BP and SZ and contribute to the understanding of their neural underpinnings.


Assuntos
Transtorno Bipolar , Esquizofrenia , Humanos , Imagem de Tensor de Difusão , Neuroimagem , Imageamento por Ressonância Magnética/métodos , Biomarcadores , Encéfalo
20.
Mar Drugs ; 22(2)2024 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-38393065

RESUMO

It is important to improve the production of bioactive secondary products for drug development. The Escherichia coli-Streptomyces shuttle vector pSET152 and its derived vector pIB139 containing a strong constitutive promoter ermEp* are commonly used as integrative vectors in actinomycetes. Four new integrative vectors carrying the strong constitutive promoter kasOp*, hrdBp, SCO5768p, and SP44, respectively, were constructed and proven to be functional in different mangrove-derived Streptomyces host strains by using kanamycin resistance gene neo as a reporter. Some biosynthetic genes of elaiophylins, azalomycin Fs, and armeniaspirols were selected and inserted into these vectors to overexpress in their producers including Streptomyces sp. 219807, Streptomyces sp. 211726, and S. armeniacus DSM 43125, resulting in an approximately 1.1-1.4-fold enhancement of the antibiotic yields.


Assuntos
Actinobacteria , Streptomyces , Streptomyces/genética , Antibacterianos , Regiões Promotoras Genéticas/genética , Vetores Genéticos , Actinobacteria/genética , Plasmídeos
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