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1.
Cell ; 139(1): 212-212.e1, 2009 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-19804764

RESUMO

The translational apparatus is one of the major targets for antibiotics in the bacterial cell. Antibiotics predominantly interact with the functional centers of the ribosome, namely the messenger RNA (mRNA)-transfer RNA (tRNA) decoding region on the 30S subunit, the peptidyltransferase center on the 50S subunit, or the ribosomal exit tunnel through which the nascent polypeptide chain passes during translation. Protein synthesis can be divided into three phases: initiation, elongation, and termination/recycling.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , RNA Bacteriano/metabolismo , RNA de Transferência/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo
3.
Proc Natl Acad Sci U S A ; 105(36): 13339-44, 2008 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-18757750

RESUMO

The oxazolidinones represent the first new class of antibiotics to enter into clinical usage within the past 30 years, but their binding site and mechanism of action has not been fully characterized. We have determined the crystal structure of the oxazolidinone linezolid bound to the Deinococcus radiodurans 50S ribosomal subunit. Linezolid binds in the A site pocket at the peptidyltransferase center of the ribosome overlapping the aminoacyl moiety of an A-site bound tRNA as well as many clinically important antibiotics. Binding of linezolid stabilizes a distinct conformation of the universally conserved 23S rRNA nucleotide U2585 that would be nonproductive for peptide bond formation. In conjunction with available biochemical data, we present a model whereby oxazolidinones impart their inhibitory effect by perturbing the correct positioning of tRNAs on the ribosome.


Assuntos
Antibacterianos/química , Oxazolidinonas/química , Peptidil Transferases/química , Peptidil Transferases/metabolismo , RNA de Transferência/química , RNA de Transferência/metabolismo , Ribossomos/enzimologia , Antibacterianos/farmacologia , Sítios de Ligação , Deinococcus/efeitos dos fármacos , Deinococcus/enzimologia , Modelos Moleculares , Conformação de Ácido Nucleico , Oxazolidinonas/farmacologia , Ligação Proteica , Estrutura Terciária de Proteína , Ribossomos/efeitos dos fármacos
4.
Mol Cell ; 30(1): 26-38, 2008 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-18406324

RESUMO

The thiopeptide class of antibiotics targets the GTPase-associated center (GAC) of the ribosome to inhibit translation factor function. Using X-ray crystallography, we have determined the binding sites of thiostrepton (Thio), nosiheptide (Nosi), and micrococcin (Micro), on the Deinococcus radiodurans large ribosomal subunit. The thiopeptides, by binding within a cleft located between the ribosomal protein L11 and helices 43 and 44 of the 23S rRNA, overlap with the position of domain V of EF-G, thus explaining how this class of drugs perturbs translation factor binding to the ribosome. The presence of Micro leads to additional density for the C-terminal domain (CTD) of L7, adjacent to and interacting with L11. The results suggest that L11 acts as a molecular switch to control L7 binding and plays a pivotal role in positioning one L7-CTD monomer on the G' subdomain of EF-G to regulate EF-G turnover during protein synthesis.


Assuntos
Bacteriocinas , Regulação da Expressão Gênica , Peptídeos , Biossíntese de Proteínas , Proteínas Ribossômicas/química , Proteínas Ribossômicas/metabolismo , Ribossomos , Tioestreptona , Antibacterianos/química , Antibacterianos/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Bacteriocinas/química , Bacteriocinas/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Deinococcus/química , Deinococcus/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Molecular , Peptídeos/química , Peptídeos/metabolismo , Estrutura Terciária de Proteína , Proteínas Ribossômicas/genética , Ribossomos/química , Ribossomos/metabolismo , Tiazóis/química , Tiazóis/metabolismo , Tioestreptona/química , Tioestreptona/metabolismo
5.
Expert Opin Pharmacother ; 9(2): 267-83, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18201149

RESUMO

Ketolides differ from macrolides by removal of the 3-O-cladinose (replaced by a keto group), a 11,12- or 6,11-cyclic moiety and a heteroaryl-alkyl side chain attached to the macrocyclic ring through a suitable linker. These modifications allow for anchoring at two distinct binding sites in the 23S rRNA (increasing activity against erythromycin-susceptible strains and maintaining activity towards Streptococcus pneumoniae resistant to erythromycin A by ribosomal methylation), and make ketolides less prone to induce methylase expression and less susceptible to efflux in S. pneumoniae. Combined with an advantageous pharmacokinetic profile (good oral bioavailability and penetration in the respiratory tract tissues and fluids; prolonged half-life allowing for once-a-day administration), these antimicrobial properties make ketolides an attractive alternative for the treatment of severe respiratory tract infections such as pneumonia in areas with significant resistance to conventional macrolides. For telithromycin (the only registered ketolide so far), pharmacodynamic considerations suggest optimal efficacy for isolates with minimum inhibitory concentration values < or = 0.25 mg/l (pharmacodynamic/pharmacokinetic breakpoint), calling for continuous and careful surveys of bacterial susceptibility. Postmarketing surveillance studies have evidenced rare, but severe, side effects (hepatotoxicity, respiratory failure in patients with myasthenia gravis, visual disturbance and QTc prolongation in combination with other drugs). On these bases, telithromycin indications have been recently restricted by the US FDA to community-acquired pneumonia, and caution in patients at risk has been advocated by the European authorities. Should these side effects be class related, they may hinder the development of other ketolides such as cethromycin (in Phase III, but on hold in the US) or EDP-420 (Phase II).


Assuntos
Cetolídeos/química , Cetolídeos/uso terapêutico , Macrolídeos/química , Macrolídeos/uso terapêutico , Infecções Respiratórias/tratamento farmacológico , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/uso terapêutico , Sítios de Ligação/fisiologia , Humanos , Cetolídeos/metabolismo , Macrolídeos/metabolismo , Infecções Respiratórias/metabolismo
6.
Structure ; 15(3): 289-97, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17355865

RESUMO

In the initiation phase of bacterial translation, the 30S ribosomal subunit captures mRNA in preparation for binding with initiator tRNA. The purine-rich Shine-Dalgarno (SD) sequence, in the 5' untranslated region of the mRNA, anchors the 30S subunit near the start codon, via base pairing with an anti-SD (aSD) sequence at the 3' terminus of 16S rRNA. Here, we present the 3.3 A crystal structure of the Thermus thermophilus 30S subunit bound with an mRNA mimic. The duplex formed by the SD and aSD sequences is snugly docked in a "chamber" between the head and platform domains, demonstrating how the 30S subunit captures and stabilizes the otherwise labile SD helix. This location of the SD helix is suitable for the placement of the start codon AUG in the immediate vicinity of the mRNA channel, in agreement with reported crosslinks between the second position of the start codon and G1530 of 16S rRNA.


Assuntos
RNA Bacteriano/química , RNA Bacteriano/metabolismo , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Ribossomos/química , Ribossomos/metabolismo , Sítios de Ligação/genética , Cristalografia por Raios X , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína , Thermus thermophilus/química , Thermus thermophilus/genética , Thermus thermophilus/metabolismo
7.
Nat Struct Mol Biol ; 13(10): 871-8, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16998488

RESUMO

Kasugamycin (Ksg) specifically inhibits translation initiation of canonical but not of leaderless messenger RNAs. Ksg inhibition is thought to occur by direct competition with initiator transfer RNA. The 3.35-A structure of Ksg bound to the 30S ribosomal subunit presented here provides a structural description of two Ksg-binding sites as well as a basis for understanding Ksg resistance. Notably, neither binding position overlaps with P-site tRNA; instead, Ksg mimics codon nucleotides at the P and E sites by binding within the path of the mRNA. Coupled with biochemical experiments, our results suggest that Ksg indirectly inhibits P-site tRNA binding through perturbation of the mRNA-tRNA codon-anticodon interaction during 30S canonical initiation. In contrast, for 70S-type initiation on leaderless mRNA, the overlap between mRNA and Ksg is reduced and the binding of tRNA is further stabilized by the presence of the 50S subunit, minimizing Ksg efficacy.


Assuntos
Aminoglicosídeos/farmacologia , Escherichia coli/química , Iniciação Traducional da Cadeia Peptídica , RNA Bacteriano/química , RNA Mensageiro/química , RNA de Transferência/metabolismo , Aminoglicosídeos/química , Aminoglicosídeos/metabolismo , Antibacterianos/química , Sítios de Ligação , Códon , Modelos Moleculares , Nucleotídeos/química , Estrutura Terciária de Proteína , RNA de Transferência/química , Relação Estrutura-Atividade
8.
FEBS Lett ; 579(15): 3207-13, 2005 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-15943964

RESUMO

RNA protection experiments and the crystal structure of a complex of the large ribosomal subunit from the eubacterium Deinococcus radiodurans with rapamycin, a polyketide compound resembling macrolides and ketolides, showed that rapamycin binds to a crevice located at the boundaries of the nascent protein exit tunnel, near its entrance. At this location rapamycin cannot occlude the ribosome exit tunnel, consistent with its failure to act as a ribosomal antibiotic drug. In accord with recent biochemical data, this crevice may play a role in facilitating local cotranslational folding of nascent chains, in particular for transmembrane proteins.


Assuntos
Deinococcus/química , Biossíntese de Proteínas , Dobramento de Proteína , Ribossomos/química , Ribossomos/metabolismo , Sequência de Bases , Sítios de Ligação , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , Biossíntese de Proteínas/efeitos dos fármacos , RNA Ribossômico 23S/química , RNA Ribossômico 23S/genética , RNA Ribossômico 23S/metabolismo , Ribossomos/efeitos dos fármacos , Sirolimo/química , Sirolimo/metabolismo , Sirolimo/farmacologia
9.
EMBO J ; 24(2): 251-60, 2005 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-15616575

RESUMO

This study presents the crystal structure of domain I of the Escherichia coli ribosome recycling factor (RRF) bound to the Deinococcus radiodurans 50S subunit. The orientation of RRF is consistent with the position determined on a 70S-RRF complex by cryoelectron microscopy (cryo-EM). Alignment, however, requires a rotation of 7 degrees and a shift of the cryo-EM RRF by a complete turn of an alpha-helix, redefining the contacts established with ribosomal components. At 3.3 A resolution, RRF is seen to interact exclusively with ribosomal elements associated with tRNA binding and/or translocation. Furthermore, these results now provide a high-resolution structural description of the conformational changes that were suspected to occur on the 70S-RRF complex, which has implications for the synergistic action of RRF with elongation factor G (EF-G). Specifically, the tip of the universal bridge element H69 is shifted by 20 A toward h44 of the 30S subunit, suggesting that RRF primes the intersubunit bridge B2a for the action of EF-G. Collectively, our data enable a model to be proposed for the dual action of EF-G and RRF during ribosome recycling.


Assuntos
Proteínas/metabolismo , Ribossomos/metabolismo , Sequência de Aminoácidos , Microscopia Crioeletrônica , Cristalografia por Raios X , Deinococcus/metabolismo , Escherichia coli/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Proteínas Ribossômicas , Homologia de Sequência de Aminoácidos
10.
FEBS Lett ; 567(1): 20-6, 2004 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15165888

RESUMO

The linkage between internal ribosomal symmetry and transfer RNA (tRNA) positioning confirmed positional catalysis of amino-acid polymerization. Peptide bonds are formed concurrently with tRNA-3' end rotatory motion, in conjunction with the overall messenger RNA (mRNA)/tRNA translocation. Accurate substrate alignment, mandatory for the processivity of protein biosynthesis, is governed by remote interactions. Inherent flexibility of a conserved nucleotide, anchoring the rotatory motion, facilitates chirality discrimination and antibiotics synergism. Potential tRNA interactions explain the universality of the tRNA CCA-end and P-site preference of initial tRNA. The interactions of protein L2 tail with the symmetry-related region periphery explain its conservation and its contributions to nascent chain elongation.


Assuntos
Cristalografia por Raios X/métodos , Ribossomos/química , Ribossomos/ultraestrutura , Aminoácidos/química , Antibacterianos/química , Azitromicina/farmacologia , Catálise , Modelos Moleculares , Peptídeos/química , Isoformas de Proteínas , Estrutura Terciária de Proteína , Transporte Proteico , RNA Mensageiro/metabolismo , RNA de Transferência/química , RNA de Transferência/metabolismo , Especificidade por Substrato , Virginiamicina/farmacologia
11.
Biopolymers ; 70(1): 19-41, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12925991

RESUMO

Ribosomes, the universal cellular organelles catalyzing the translation of genetic code into proteins, are protein/RNA assemblies, of a molecular weight 2.5 mega Daltons or higher. They are built of two subunits that associate for performing protein biosynthesis. The large subunit creates the peptide bond and provides the path for emerging proteins. The small has key roles in initiating the process and controlling its fidelity. Crystallographic studies on complexes of the small and the large eubacterial ribosomal subunits with substrate analogs, antibiotics, and inhibitors confirmed that the ribosomal RNA governs most of its activities, and indicated that the main catalytic contribution of the ribosome is the precise positioning and alignment of its substrates, the tRNA molecules. A symmetry-related region of a significant size, containing about two hundred nucleotides, was revealed in all known structures of the large ribosomal subunit, despite the asymmetric nature of the ribosome. The symmetry rotation axis, identified in the middle of the peptide-bond formation site, coincides with the bond connecting the tRNA double-helical features with its single-stranded 3' end, which is the moiety carrying the amino acids. This thus implies sovereign movements of tRNA features and suggests that tRNA translocation involves a rotatory motion within the ribosomal active site. This motion is guided and anchored by ribosomal nucleotides belonging to the active site walls, and results in geometry suitable for peptide-bond formation with no significant rearrangements. The sole geometrical requirement for this proposed mechanism is that the initial P-site tRNA adopts the flipped orientation. The rotatory motion is the major component of unified machinery for peptide-bond formation, translocation, and nascent protein progression, since its spiral nature ensures the entrance of the nascent peptide into the ribosomal exit tunnel. This tunnel, assumed to be a passive path for the growing chains, was found to be involved dynamically in gating and discrimination.


Assuntos
Cristalografia por Raios X/métodos , Ribossomos/química , Antibacterianos/química , Domínio Catalítico , Modelos Moleculares , Conformação Molecular , Conformação de Ácido Nucleico , Peptídeos/química , Peptidil Transferases/química , Ligação Proteica , Conformação Proteica , RNA/química , RNA de Transferência/química , Tetraciclina/química
12.
J Bacteriol ; 185(14): 4276-9, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12837804

RESUMO

The crystal structure of the ketolide telithromycin bound to the Deinococcus radiodurans large ribosomal subunit shows that telithromycin blocks the ribosomal exit tunnel and interacts with domains II and V of the 23S RNA. Comparisons to other clinically relevant macrolides provided structural insights into its enhanced activity against macrolide-resistant strains.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Deinococcus/efeitos dos fármacos , Farmacorresistência Bacteriana , Eritromicina/análogos & derivados , Cetolídeos , Macrolídeos , Antibacterianos/metabolismo , Sítios de Ligação , Cristalização , Cristalografia por Raios X , Deinococcus/genética , Deinococcus/metabolismo , Eritromicina/química , Eritromicina/metabolismo , Eritromicina/farmacologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , RNA Ribossômico 23S/genética , RNA Ribossômico 23S/metabolismo
13.
Eur J Biochem ; 270(12): 2543-56, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12787020

RESUMO

High-resolution crystal structures of large ribosomal subunits from Deinococcus radiodurans complexed with tRNA-mimics indicate that precise substrate positioning, mandatory for efficient protein biosynthesis with no further conformational rearrangements, is governed by remote interactions of the tRNA helical features. Based on the peptidyl transferase center (PTC) architecture, on the placement of tRNA mimics, and on the existence of a two-fold related region consisting of about 180 nucleotides of the 23S RNA, we proposed a unified mechanism integrating peptide bond formation, A-to-P site translocation, and the entrance of the nascent protein into its exit tunnel. This mechanism implies sovereign, albeit correlated, motions of the tRNA termini and includes a spiral rotation of the A-site tRNA-3' end around a local two-fold rotation axis, identified within the PTC. PTC features, ensuring the precise orientation required for the A-site nucleophilic attack on the P-site carbonyl-carbon, guide these motions. Solvent mediated hydrogen transfer appears to facilitate peptide bond formation in conjunction with the spiral rotation. The detection of similar two-fold symmetry-related regions in all known structures of the large ribosomal subunit, indicate the universality of this mechanism, and emphasizes the significance of the ribosomal template for the precise alignment of the substrates as well as for accurate and efficient translocation. The symmetry-related region may also be involved in regulatory tasks, such as signal transmission between the ribosomal features facilitating the entrance and the release of the tRNA molecules. The protein exit tunnel is an additional feature that has a role in cellular regulation. We showed by crystallographic methods that this tunnel is capable of undergoing conformational oscillations and correlated the tunnel mobility with sequence discrimination, gating and intracellular regulation.


Assuntos
Proteínas de Bactérias/metabolismo , Peptídeos/química , Transporte Proteico , Ribossomos/metabolismo , Proteínas de Bactérias/química , Sítios de Ligação , Deinococcus/metabolismo , Modelos Moleculares , Conformação Proteica , RNA de Transferência/química , RNA de Transferência/metabolismo
14.
Nat Struct Biol ; 10(5): 366-70, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12665853

RESUMO

Nascent proteins emerge out of ribosomes through an exit tunnel, which was assumed to be a firmly built passive path. Recent biochemical results, however, indicate that the tunnel plays an active role in sequence-specific gating of nascent chains and in responding to cellular signals. Consistently, modulation of the tunnel shape, caused by the binding of the semi-synthetic macrolide troleandomycin to the large ribosomal subunit from Deinococcus radiodurans, was revealed crystallographically. The results provide insights into the tunnel dynamics at high resolution. Here we show that, in addition to the typical steric blockage of the ribosomal tunnel by macrolides, troleandomycin induces a conformational rearrangement in a wall constituent, protein L22, flipping the tip of its highly conserved beta-hairpin across the tunnel. On the basis of mutations that alleviate elongation arrest, the tunnel motion could be correlated with sequence discrimination and gating, suggesting that specific arrest motifs within nascent chain sequences may induce a similar gating mechanism.


Assuntos
Ribossomos/fisiologia , Ribossomos/ultraestrutura , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Proteínas Ribossômicas/química , Proteínas Ribossômicas/ultraestrutura , Transdução de Sinais
15.
Mol Cell ; 11(1): 91-102, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12535524

RESUMO

Crystal structures of tRNA mimics complexed with the large ribosomal subunit of Deinococcus radiodurans indicate that remote interactions determine the precise orientation of tRNA in the peptidyl-transferase center (PTC). The PTC tolerates various orientations of puromycin derivatives and its flexibility allows the conformational rearrangements required for peptide-bond formation. Sparsomycin binds to A2602 and alters the PTC conformation. H69, the intersubunit-bridge connecting the PTC and decoding site, may also participate in tRNA placement and translocation. A spiral rotation of the 3' end of the A-site tRNA around a 2-fold axis of symmetry identified within the PTC suggests a unified ribosomal machinery for peptide-bond formation, A-to-P-site translocation, and entrance of nascent proteins into the exit tunnel. Similar 2-fold related regions, detected in all known structures of large ribosomal subunits, indicate the universality of this mechanism.


Assuntos
Deinococcus/genética , Conformação de Ácido Nucleico , Biossíntese de Proteínas , Conformação Proteica , Aminoacil-RNA de Transferência/química , Proteínas Ribossômicas/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Inibidores da Síntese de Proteínas/química , Inibidores da Síntese de Proteínas/metabolismo , Puromicina/química , Puromicina/metabolismo , Aminoacil-RNA de Transferência/genética , Aminoacil-RNA de Transferência/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Esparsomicina/química , Esparsomicina/metabolismo
16.
Curr Drug Targets Infect Disord ; 2(2): 169-86, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12462147

RESUMO

Resistance to antibiotics is a major problem in modern therapeutics. Ribosomes, the cellular organelle catalyzing the translation of the genetic code into proteins, are targets for several clinically relevant antibiotics. The ribosomes from eubacteria are excellent pathogen models. High resolution structures of the large and small ribosomal subunits were used as references that allowed unambiguous localization of almost a dozen antibiotic drugs, most of which are clinically relevant. Analyses of these structures showed a great diversity in the antibiotics' modes of action, such as interference with substrate binding, hindrance of the mobility required for the biosynthetic process and the blockage of tunnel which provides the path of exit for nascent proteins. All antibiotics studied by us were found to bind primarily to ribosomal RNA and, except for one allosteric effect, their binding did not cause major conformational changes. Antibiotics of the small ribosomal subunit may hinder tRNA binding, decoding, translocation, and the initiation of the entire biosynthetic process. The large subunit agents may target the GTPase center, interfere with peptide bond formation, or block the entrance of the nascent protein exit tunnel. The overall structure of the peptidyl transferase center and the modes of action of the antibiotic agents indicate that the ribosome serves as a template for proper positioning of tRNAs, rather than participating actively in the catalytic events associated with the creation of peptide bonds.


Assuntos
Antibacterianos/farmacologia , Ribossomos/efeitos dos fármacos , Cristalografia , Farmacorresistência Bacteriana , Macrolídeos , Biossíntese de Proteínas , Conformação Proteica , Ribossomos/química , Tetraciclina/farmacologia
17.
Curr Protein Pept Sci ; 3(1): 55-65, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12370011

RESUMO

Analysis of the high resolution structure of the small subunit from Thermus thermophilus shed light on its inherent conformational variability and indicated an interconnected network of features allowing concerted movements during translocation. It also showed that conformational rearrangements may be involved in subunit association and that a latch-like movement guarantees processivity and ensures maximized fidelity. Conformational mobility is associated with the binding and the anti association function of initiation factor 3, and antibiotics interfering with prevent the initiation of the biosynthetic process. Proteins stabilize the structure mainly by their long basic extensions that penetrate into the ribosomal RNA. When pointing into the solution, these extensions may have functional roles in binding of non-ribosomal factors participating in the process of protein biosynthesis. In addition, although the decoding center is formed of RNA, proteins seem to serve ancillary functions such as stabilizing ist required conformation and assisting the directionality of the translocation.


Assuntos
Proteínas de Bactérias/biossíntese , Iniciação Traducional da Cadeia Peptídica , Biossíntese de Proteínas/fisiologia , RNA Bacteriano/metabolismo , RNA de Transferência/metabolismo , Ribossomos/metabolismo , Thermus thermophilus/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Edeína/farmacologia , Técnicas In Vitro , Conformação de Ácido Nucleico , Conformação Proteica , Inibidores da Síntese de Proteínas/farmacologia , RNA de Transferência/química , Proteínas Ribossômicas/metabolismo , Ribossomos/química , Tetraciclina/farmacologia , Thermus thermophilus/genética
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