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1.
Proteins ; 85(1): 177-181, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27699884

RESUMO

Zoocin A is a Zn-metallopeptidase secreted by Streptococcus zooepidemicus strain 4881. Its catalytic domain is responsible for cleaving the D-alanyl-L-alanine peptide bond in streptococcal peptidoglycan. The solution NMR structure of the Cys74 to Ala74 mutant of the recombinant catalytic domain (rCAT C74A) has been determined. With a previous structure determination for the recombinant target recognition domain (rTRD), this completes the 3D structure of zoocin A. While the structure of rCAT C74A resembles those of the catalytic domains of lysostaphin and LytM, the substrate binding groove is wider and no tyrosine residue was observed in the active site. Proteins 2016; 85:177-181. © 2016 Wiley Periodicals, Inc.


Assuntos
Alanina/química , Proteínas de Bactérias/química , Bacteriocinas/química , Cisteína/química , Mutação , Streptococcus equi/química , Alanina/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Domínio Catalítico , Clonagem Molecular , Cisteína/metabolismo , Endopeptidases/química , Endopeptidases/genética , Endopeptidases/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Cinética , Lisostafina/química , Lisostafina/metabolismo , Modelos Moleculares , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Streptococcus equi/enzimologia , Especificidade por Substrato
2.
FEMS Microbiol Lett ; 349(1): 25-31, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24111714

RESUMO

Antisense oligonucleotides (AS-ODN) target genes in a sequence-specific manner inhibit gene function and have potential use as antimicrobial agents. Cell barriers, such as peptidoglycan, cell surface proteins and lipopolysaccharide membranes, prevent delivery of AS-ODN into the bacterial cell, limiting their use as an effective treatment option. The ß-lactam antibiotic penicillin was examined for its ability to deliver phosphorothioate oligodeoxyribonucleotides (PS-ODNs) and γ(32) P-ODN into Streptococcus mutans OMZ175. Treatment of lag-phase S. mutans OMZ175 cells with penicillin and FBA (PS-ODN targeting the fructose-biphosphate aldolase gene), resulted in prolonged suppression of growth (> 24 h) and fba expression (656.9 ± 194.4-fold decrease at 5 h). Suppression of both cell growth and fba expression corresponded with a greater amount of γ(32) P-ODN becoming cell associated, with a maximum γ(32) P-ODN concentration per cell achieved 5 h after penicillin treatment (6.50 ± 1.39 × 10(8) molecules per CFU). This study confirms that for S. mutans OMZ175, the peptidoglycan layer acts as a major barrier preventing AS-ODN penetration and suggests that the use of agents such as penicillin that interfere with peptidoglycan integrity can significantly increase the uptake of PS-ODN by these cells.


Assuntos
Oligodesoxirribonucleotídeos Antissenso/metabolismo , Penicilinas/farmacologia , Streptococcus mutans/efeitos dos fármacos , Proteínas de Bactérias/genética , Divisão Celular/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Técnicas Genéticas , Oligodesoxirribonucleotídeos Antissenso/genética , Peptidoglicano/metabolismo , Streptococcus mutans/metabolismo
3.
Biochem Biophys Res Commun ; 441(2): 297-300, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24076386

RESUMO

A docking model is proposed for the target recognition domain of the lytic exoenzyme zoocin A with the peptidoglycan on the outer cell surface of sensitive bacterial strains. Solubilized fragments from such peptidoglycans perturb specific backbone and side chain amide resonances in the recombinant form of the domain designated rTRD as detected in two-dimensional (1)H-(15)N correlation NMR spectra. The affected residues comprise a shallow surface cleft on the protein surface near W115, N53, N117, and Q105 among others, which interacts with the peptide portion of the peptidoglycan. Calculations with AutoDock Vina provide models of the docking interface. There is approximate homology between the rTDR-peptidoglycan docking site and the antigen binding site of Fab antibodies with the immunoglobin fold. EDTA was also found to bind to rTRD, but at a site distinct from the proposed peptidoglycan docking site.


Assuntos
Proteínas de Bactérias/química , Peptidoglicano/química , Antígenos/química , Sítios de Ligação , Simulação por Computador , Fragmentos Fab das Imunoglobulinas/química , Modelos Químicos , Ressonância Magnética Nuclear Biomolecular , Estrutura Terciária de Proteína
4.
Proteins ; 81(4): 722-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23184858

RESUMO

The protein rTRD is the recombinant form of the target recognition domain of zoocin A, a lytic exoenzyme produced by Streptococcus equi subspecies zooepidemicus 4881. It has no known sequence homologs. However, the catalytic domain of zoocin A is homologous to lysostaphin which is another exoenzyme active against a different spectrum of bacteria, including the pathogen Staphylococcus aureus. An ensemble of models for the solution structure of rTRD has been generated by NMR techniques. The minimum energy model from the ensemble was subjected to three-dimensional homology search engines, but no homologs were found, suggesting rTRD may represent a new protein folding family. There is some similarity in the folding of rTRD to the immunoglobin fold of the antigen binding region of mammalian antibodies which could suggest an ancient evolutionary relation.


Assuntos
Proteínas de Bactérias/química , Streptococcus equi/química , Sequência de Aminoácidos , Lisostafina/química , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Estrutura Terciária de Proteína , Proteínas Recombinantes/química
5.
FEMS Microbiol Lett ; 317(1): 93-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21251053

RESUMO

The use of antisense oligodeoxyribonucleotides (asODNs) to inhibit gene function has proven to be an extremely powerful tool for establishing gene-function relationships. Diffusion limitations imposed by the thick peptidoglycan layer of Gram-positive bacteria have proven difficult to overcome for permeability of asODNs. Typically, introduction of the asODN is achieved by cloning the antisense sequence into a vector downstream of an inducible promoter and transforming this construct into the cell of interest. In this study, we report that the use of the streptococcolytic enzyme zoocin A facilitated entry of phosphorothioate oligodeoxyribonucleotides (PS-ODNs) into Streptococcus mutans, such that the degree of phenotypic response (cell growth inhibition) observed was sequence specific and correlated with the amount of zoocin A (R(2) =0.9919) or PS-ODN (R(2) =0.9928) used. Quantitative reverse transcriptase PCR was used to demonstrate that only the expression of the target gene against which the PS-ODN was designed was affected. We believe that the use of an appropriate bacteriolytic enzyme to facilitate entry of asODNs into bacterial cells provides a method that will be generally useful in the study of gene regulation in Gram-positive bacteria.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Oligodesoxirribonucleotídeos Antissenso/metabolismo , Streptococcus mutans/genética , Perfilação da Expressão Gênica , Inibidores do Crescimento/genética , Inibidores do Crescimento/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Streptococcus mutans/crescimento & desenvolvimento
6.
Appl Environ Microbiol ; 76(20): 6944-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20729317

RESUMO

Resistance to lysostaphin, a staphylolytic glycylglycine endopeptidase, is due to a FemABX-like immunity protein that inserts serines in place of some glycines in peptidoglycan cross bridges. These modifications inhibit both binding of the recombinant cell wall targeting domain and catalysis by the recombinant catalytic domain of lysostaphin.


Assuntos
Lisostafina/antagonistas & inibidores , Peptidoglicano/metabolismo , Staphylococcus/enzimologia , Parede Celular
7.
Appl Environ Microbiol ; 75(19): 6205-10, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19684178

RESUMO

Producer cell immunity to the streptococcolytic enzyme zoocin A, which is a D-alanyl-L-alanine endopeptidase, is due to Zif, the zoocin A immunity factor. Zif has high degrees of similarity to MurM and MurN (members of the FemABX family of proteins), which are responsible for the addition of amino acids to cross bridges during peptidoglycan synthesis in streptococci. In this study, purified peptidoglycans from strains with and without zif were compared to determine how Zif modifies the peptidoglycan layer to cause resistance to zoocin A. The peptidoglycan from each strain was hydrolyzed using the streptococcolytic phage lysin B30, and the resulting muropeptides were separated by reverse-phase high-pressure liquid chromatography, labeled with 4-sulfophenyl isothiocyanate, and analyzed by tandem mass spectrometry in the negative-ion mode. It was determined that Zif alters the peptidoglycan by increasing the proportion of cross bridges containing three L-alanines instead of two. This modification decreased binding of the recombinant target recognition domain of zoocin A to peptidoglycan. Zif-modified peptidoglycan also was less susceptible to hydrolysis by the recombinant catalytic domain of zoocin A. Thus, Zif is a novel FemABX-like immunity factor because it provides resistance to a bacteriolytic endopeptidase by lengthening the peptidoglycan cross bridge rather than by causing an amino acid substitution.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Proteínas de Bactérias/fisiologia , Farmacorresistência Bacteriana , Streptococcus equi/efeitos dos fármacos , Streptococcus equi/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Parede Celular/química , Cromatografia Líquida de Alta Pressão , Mucoproteínas/metabolismo , Peptidoglicano/química , Peptidoglicano/isolamento & purificação , Streptococcus equi/metabolismo , Espectrometria de Massas em Tandem , Proteínas Virais/metabolismo
8.
J Mol Evol ; 68(5): 498-505, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19357799

RESUMO

Zoocin A is a streptococcolytic enzyme produced by Streptococcus equi subsp. zooepidemicus strain 4881. The zoocin A gene (zooA) and the gene specifying resistance to zoocin A (zif) are adjacent on the chromosome and are divergently transcribed. Twenty-four S. equi subsp. zooepidemicus strains were analyzed to determine the genetic difference among three previously characterized as zoocin A producers (strains 4881, 9g, and 9h) and the 21 nonproducers. LT-PCR and Southern hybridization studies revealed that none of the nonproducer strains possessed zooA or zif. RAPD and PFGE showed that the 24 strains were a genetically diverse population with eight RAPD profiles. S. equi subsp. zooepidemicus strains 9g and 9h appeared to be genetically identical to each other but quite different from strain 4881. Sequences derived from 4881 and 9g showed that zooA and zif were integrated into the chromosome adjacent to the gene flaR. A comparison of these sequences with the genome sequences of S. equi subsp. zooepidemicus strains H70 and MGCS10565 and S. equi subsp. equi strain 4047 suggests that flaR flanks a region of genome plasticity in this species.


Assuntos
Proteínas de Bactérias/genética , Genes Bacterianos , Streptococcus equi/enzimologia , Streptococcus equi/genética , Eletroforese em Gel de Campo Pulsado , Fenótipo , Filogenia , Análise de Sequência de DNA , Streptococcus equi/isolamento & purificação
9.
Appl Environ Microbiol ; 75(1): 72-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18978086

RESUMO

Zoocin A is a streptococcolytic peptidoglycan hydrolase with an unknown site of action that is produced by Streptococcus equi subsp. zooepidemicus 4881. Zoocin A has now been determined to be a d-alanyl-l-alanine endopeptidase by digesting susceptible peptidoglycan with a combination of mutanolysin and zoocin A, separating the resulting muropeptides by reverse-phase high-pressure liquid chromatography, and analyzing them by mass spectrometry (MS) in both the positive- and negative-ion modes to determine their compositions. In order to distinguish among possible structures for these muropeptides, they were N-terminally labeled with 4-sulfophenyl isothiocyanate (SPITC) and analyzed by tandem MS in the negative-ion mode. This novel application of SPITC labeling and MS/MS analysis can be used to analyze the structure of peptidoglycans and to determine the sites of action of other peptidoglycan hydrolases.


Assuntos
Proteínas de Bactérias/metabolismo , Benzenossulfonatos/metabolismo , Isotiocianatos/metabolismo , Espectrometria de Massas , Peptidoglicano/metabolismo , Coloração e Rotulagem/métodos , Streptococcus equi/enzimologia
10.
J Biol Inorg Chem ; 13(6): 855-60, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18386079

RESUMO

Direct metal analysis of the bacteriolytic exoenzyme zoocin A failed to unequivocally identify a putative metal cofactor; hence, indirect experiments utilizing NMR were undertaken to settle this question. Cd(2+) as a surrogate metal ion was reconstituted into EDTA-treated, metal-free recombinant zoocin, and (113)Cd-NMR was employed to explore binding in the protein for this ion. The Cd-substituted enzyme was found to have 80-85% of native streptococcolytic activity. A major (113)Cd resonance at 113.6 ppm was observed which with time split into resonances at 113.6 and 107.2 ppm. A minor (113)Cd resonance at 87.3 ppm was observed which increased in intensity with time. These Cd chemical shifts are indicative of two N atoms and two O atoms ligating directly to the metal site. On the basis of conserved amino acid residues in a homologous protein of known structure, LytM, the ligands in zoocin are tentatively assigned to H45, D49, H133, and some combination of water or buffer ions as the fourth oxygen donor in zoocin A. Comparison of the combined intensities for (113)Cd-substituted zoocin with a known quantity of another Cd-substituted protein gave Cd binding as approximately stoichiometric (1.2+/-0.2) with protein. Additional metal-removal and reconstitution experiments on the recombinant catalytic domain of zoocin implicate Zn(2+) as the metal cofactor. Therefore, the evidence supports zoocin as a single Zn(2+) ion binding metalloenzyme.


Assuntos
Proteínas de Bactérias/química , Cádmio/química , Sítios de Ligação , Isótopos , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/normas , Isótopos de Nitrogênio , Prótons , Padrões de Referência , Sensibilidade e Especificidade , Zinco/química
11.
Appl Environ Microbiol ; 73(17): 5507-15, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17630314

RESUMO

There is increasing concern regarding the presence of vancomycin-resistant enterococci in domestically farmed animals, which may act as reservoirs and vehicles of transmission for drug-resistant enterococci to humans, resulting in serious infections. In order to assess the potential for the use of monolaurin as a food preservative, it is important to understand both its target and potential mechanisms of resistance. A Tn917 mutant library of Enterococcus faecalis AR01/DGVS was screened for resistance (MIC, >100 microg/ml) to monolaurin. Three mutants were identified as resistant to monolaurin and were designated DGRM2, DGRM5, and DGRM12. The gene interrupted in all three mutants was identified as traB, which encodes an E. faecalis pheromone shutdown protein and whose complementation in trans restored monolaurin sensitivity in all three mutants. DGRM2 was selected for further characterization. E. faecalis DGRM2 showed increased resistance to gentamicin and chloramphenicol (inhibitors of protein synthesis), while no difference in the MIC was observed with the cell wall-active antibiotics penicillin and vancomycin. E. faecalis AR01/DGVS and DGRM2 were shown to have similar rates (30% cell lysis after 4 h) of cell autolytic activity when activated by monolaurin. Differences in cell surface hydrophobicity were observed between the wild type and the mutant, with the cell surface of the parent strain being significantly more hydrophobic. Analysis of the cell wall structure of DGRM2 by transmission electron microscopy revealed an increase in the apparent cell wall thickness and contraction of its cytoplasm. Taken together, these results suggest that the increased resistance of DGRM2 was due to a change in cell surface hydrophobicity, consequently limiting the diffusion of monolaurin to a potential target in the cytoplasmic membrane and/or cytoplasm of E. faecalis.


Assuntos
Farmacorresistência Bacteriana , Enterococcus faecalis/efeitos dos fármacos , Tensoativos/farmacologia , Animais , Proteínas de Bactérias/genética , Membrana Celular/química , Membrana Celular/ultraestrutura , Elementos de DNA Transponíveis , Cães , Farmacorresistência Bacteriana/genética , Enterococcus faecalis/crescimento & desenvolvimento , Enterococcus faecalis/isolamento & purificação , Ácidos Graxos/análise , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/veterinária , Interações Hidrofóbicas e Hidrofílicas , Lauratos/farmacologia , Mastite/microbiologia , Mastite/veterinária , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Monoglicerídeos/farmacologia , Mutagênese , Mutação
12.
FEMS Microbiol Lett ; 270(1): 155-61, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17319876

RESUMO

Zoocin A is a domain-structured peptidoglycan hydrolase produced by Streptococcus equi ssp. zooepidemicus 4881. [(14)C]-zoocin A was used to measure the amount of zoocin A bound to the surface of cells and to purified peptidoglycan. The sensitivity of various streptococci to zoocin A correlated with the amount of zoocin A bound (R(2)=0.8609). Peptidoglycan purified from Streptococcus oralis and Streptococcus rattus were able to bind zoocin A but remained resistant to hydrolysis. All Streptococcus pyogenes strains were extremely sensitive to zoocin A with minimum inhibition concentrations of 31.5 ng mL(-1) or less, suggesting that zoocin A may have potential for use as an enzybiotic.


Assuntos
Proteínas de Bactérias/farmacologia , Streptococcus equi/metabolismo , Streptococcus/metabolismo , Proteínas de Bactérias/metabolismo , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Radioisótopos de Carbono , Testes de Sensibilidade Microbiana , Peptidoglicano/metabolismo , Ligação Proteica , Streptococcus/efeitos dos fármacos , Streptococcus equi/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/metabolismo
13.
J Food Prot ; 67(7): 1438-43, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15270498

RESUMO

A laboratory scale system, partially reproducing dairy plant conditions, was developed to quantify the effectiveness of chlorine and alternative sanitizers in reducing the number of viable bacteria attached to stainless steel surfaces. Stainless steel tubes fouled in a continuous flow reactor were exposed to a standard clean-in-place regime (water rinse, 1% sodium hydroxide at 70 degrees C for 10 min, water rinse, 0.8% nitric acid at 70 degrees C for 10 min, water rinse) followed by exposure to either chlorine (200 ppm) or combinations of nisin (500 ppm), lauricidin (100 ppm), and the lactoperoxidase system (LPS) (200 ppm) for 10 min or 2, 4, 8, 18, or 24 h. There was significant variation in the effectiveness of the alkaline-acid wash steps in reducing cell numbers (log reduction between 0 and 2). Following a 10-min treatment, none of the sanitizers significantly reduced the number of attached cells. Two hours of exposure to chlorine, nisin + the LPS, or lauricidin + the LPS achieved 2.8, 2.2, and 1.6 log reductions, respectively. Exposure times > 2 h did not further decrease the number of viable bacteria attached to the stainless steel. The effectiveness of combinations of nisin, lauricidin, and the LPS was similar to that of chlorine (P > 0.05), and these sanitizers could be used to decontaminate the surfaces of small-volume or critical hard-to-clean milk processing equipment.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Contaminação de Equipamentos , Leite/microbiologia , Animais , Bactérias/crescimento & desenvolvimento , Bovinos , Cloro/farmacologia , Contagem de Colônia Microbiana , Indústria de Laticínios/métodos , Sinergismo Farmacológico , Feminino , Microbiologia de Alimentos , Glicerídeos/farmacologia , Lactoperoxidase , Lauratos/farmacologia , Monoglicerídeos , Nisina/farmacologia , Ácido Nítrico/farmacologia , Hidróxido de Sódio/farmacologia , Aço Inoxidável , Fatores de Tempo
14.
FEMS Microbiol Lett ; 236(2): 205-11, 2004 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-15251198

RESUMO

Zoocin A is a streptococcolytic enzyme produced by Streptococcus equi subsp. zooepidemicus 4881 that has an unknown site of action on the peptidoglycans of susceptible organisms. Analysis of a mutant strain in which the genes for zoocin A and resistance to zoocin A were inactivated revealed that this strain was more susceptible to beta-lactam antibiotics than the parental organism. Purified zoocin A had weak beta-lactamase activity, bound radioactive penicillin covalently, and its streptococcolytic activity was inhibited by penicillin. Thus, zoocin A is a penicillin-binding protein and presumably is a D-alanyl endopeptidase.


Assuntos
Proteínas de Bactérias/metabolismo , Endopeptidases/metabolismo , Proteínas de Ligação às Penicilinas/metabolismo , Streptococcus equi/enzimologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , Endopeptidases/genética , Endopeptidases/isolamento & purificação , Deleção de Genes , Genes Bacterianos , Dados de Sequência Molecular , Mutação , Proteínas de Ligação às Penicilinas/genética , Análise de Sequência de DNA , Streptococcus equi/genética , Resistência beta-Lactâmica , beta-Lactamases/genética , beta-Lactamases/isolamento & purificação , beta-Lactamases/metabolismo , beta-Lactamas/metabolismo , beta-Lactamas/farmacologia
15.
J Clin Microbiol ; 42(4): 1731-3, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15071034

RESUMO

porB PCR-amplicon restriction endonuclease analysis is a rapid, simple method developed to assess porB variation in nonserotypeable meningococci isolated during New Zealand's epidemic of meningococcal disease. Most nonserotypeable meningococci isolated between 1990 and 1999 inclusively either were type 4 (40.5%) or contained the porB variable region 1 (VR1)-19, VR2-D, VR3-7, and VR4-14a sequences (45.1%).


Assuntos
Enzimas de Restrição do DNA/metabolismo , Variação Genética , Neisseria meningitidis/classificação , Reação em Cadeia da Polimerase/métodos , Porinas/genética , Sequência de Aminoácidos , Técnicas de Tipagem Bacteriana , Surtos de Doenças , Humanos , Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/microbiologia , Dados de Sequência Molecular , Neisseria meningitidis/genética , Nova Zelândia/epidemiologia , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Sorotipagem
16.
J Clin Microbiol ; 42(4): 1742-5, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15071037

RESUMO

A multilocus restriction typing (MLRT) method was developed to reduce the number of sequencing reactions required to determine the clonal relationships among serogroup B meningococci causing an epidemic in New Zealand. MLRT was a rapid, simple, and inexpensive method, and the results had an excellent correlation with multilocus sequence typing results.


Assuntos
Enzimas de Restrição do DNA/metabolismo , Surtos de Doenças , Infecções Meningocócicas/epidemiologia , Neisseria meningitidis Sorogrupo B/classificação , Neisseria meningitidis Sorogrupo B/genética , Análise de Sequência de DNA , Alelos , Técnicas de Tipagem Bacteriana , Humanos , Infecções Meningocócicas/microbiologia , Nova Zelândia/epidemiologia , Valor Preditivo dos Testes
17.
Biochem Biophys Res Commun ; 317(2): 527-30, 2004 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-15063789

RESUMO

NMR was used to obtain spectroscopic evidence supporting a two domain model for zoocin A in which an N-terminal catalytic domain is linked by a threonine-proline rich linker to a target recognition domain responsible for recognizing the cell wall of bacteria susceptible to the bacteriolytic action of the enzyme. When cloned and separately expressed, each domain retains the folding found in the whole enzyme. Additionally, spectroscopy suggests that the target recognition domain has a conformation typical of a soluble globular protein, while the catalytic domain aggregates at low millimolar concentrations.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/classificação , Espectroscopia de Ressonância Magnética/métodos , Antibacterianos/química , Antibacterianos/classificação , Catálise , Ativação Enzimática , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
18.
FEMS Microbiol Lett ; 228(1): 115-9, 2003 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-14612246

RESUMO

To determine if the genes for lysostaphin endopeptidase (end) and lysostaphin resistance (epr) function in streptococci, we transferred these genes from Staphylococcus simulans biovar staphylolyticus into two strains of Streptococcus equi subsp. zooepidemicus. The end-containing streptococci were able to produce and process proendopeptidase. Strains containing epr were more resistant to lysis by the streptococcolytic enzyme zoocin A and amino acid analysis of the peptidoglycans of the epr-containing streptococci revealed insertion of serines in their cross bridges. This is the first report of the transfer of a femABX-like immunity factor resulting in a physiologically useful effect in a different genus.


Assuntos
Endopeptidases/genética , Lisostafina/metabolismo , Streptococcus equi/enzimologia , Streptococcus equi/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Endopeptidases/metabolismo , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Fatores R
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