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Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues

Pseudomonas aeruginosa is one of the most virulent and resistant non-fermenting Gram-negative pathogens in the clinic. Unfortunately, P. aeruginosa has acquired genes encoding metallo-β-lactamases (MβLs), enzymes able to hydrolyze most β-lactam antibiotics. SPM-1 is an MβL produced only by P. aerugi...

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Autores principales: González, Lisandro J., Moreno, Diego M., Bonomo, Robert A., Vila, Alejandro J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3879351/
https://www.ncbi.nlm.nih.gov/pubmed/24391494
http://dx.doi.org/10.1371/journal.ppat.1003817
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author González, Lisandro J.
Moreno, Diego M.
Bonomo, Robert A.
Vila, Alejandro J.
author_facet González, Lisandro J.
Moreno, Diego M.
Bonomo, Robert A.
Vila, Alejandro J.
author_sort González, Lisandro J.
collection PubMed
description Pseudomonas aeruginosa is one of the most virulent and resistant non-fermenting Gram-negative pathogens in the clinic. Unfortunately, P. aeruginosa has acquired genes encoding metallo-β-lactamases (MβLs), enzymes able to hydrolyze most β-lactam antibiotics. SPM-1 is an MβL produced only by P. aeruginosa, while other MβLs are found in different bacteria. Despite similar active sites, the resistance profile of MβLs towards β-lactams changes from one enzyme to the other. SPM-1 is unique among pathogen-associated MβLs in that it contains “atypical” second sphere residues (S84, G121). Codon randomization on these positions and further selection of resistance-conferring mutants was performed. MICs, periplasmic enzymatic activity, Zn(II) requirements, and protein stability was assessed. Our results indicated that identity of second sphere residues modulates the substrate preferences and the resistance profile of SPM-1 expressed in P. aeruginosa. The second sphere residues found in wild type SPM-1 give rise to a substrate selectivity that is observed only in the periplasmic environment. These residues also allow SPM-1 to confer resistance in P. aeruginosa under Zn(II)-limiting conditions, such as those expected under infection. By optimizing the catalytic efficiency towards β-lactam antibiotics, the enzyme stability and the Zn(II) binding features, molecular evolution meets the specific needs of a pathogenic bacterial host by means of substitutions outside the active site.
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spelling pubmed-38793512014-01-03 Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues González, Lisandro J. Moreno, Diego M. Bonomo, Robert A. Vila, Alejandro J. PLoS Pathog Research Article Pseudomonas aeruginosa is one of the most virulent and resistant non-fermenting Gram-negative pathogens in the clinic. Unfortunately, P. aeruginosa has acquired genes encoding metallo-β-lactamases (MβLs), enzymes able to hydrolyze most β-lactam antibiotics. SPM-1 is an MβL produced only by P. aeruginosa, while other MβLs are found in different bacteria. Despite similar active sites, the resistance profile of MβLs towards β-lactams changes from one enzyme to the other. SPM-1 is unique among pathogen-associated MβLs in that it contains “atypical” second sphere residues (S84, G121). Codon randomization on these positions and further selection of resistance-conferring mutants was performed. MICs, periplasmic enzymatic activity, Zn(II) requirements, and protein stability was assessed. Our results indicated that identity of second sphere residues modulates the substrate preferences and the resistance profile of SPM-1 expressed in P. aeruginosa. The second sphere residues found in wild type SPM-1 give rise to a substrate selectivity that is observed only in the periplasmic environment. These residues also allow SPM-1 to confer resistance in P. aeruginosa under Zn(II)-limiting conditions, such as those expected under infection. By optimizing the catalytic efficiency towards β-lactam antibiotics, the enzyme stability and the Zn(II) binding features, molecular evolution meets the specific needs of a pathogenic bacterial host by means of substitutions outside the active site. Public Library of Science 2014-01-02 /pmc/articles/PMC3879351/ /pubmed/24391494 http://dx.doi.org/10.1371/journal.ppat.1003817 Text en https://creativecommons.org/publicdomain/zero/1.0/ This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration, which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.
spellingShingle Research Article
González, Lisandro J.
Moreno, Diego M.
Bonomo, Robert A.
Vila, Alejandro J.
Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title_full Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title_fullStr Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title_full_unstemmed Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title_short Host-Specific Enzyme-Substrate Interactions in SPM-1 Metallo-β-Lactamase Are Modulated by Second Sphere Residues
title_sort host-specific enzyme-substrate interactions in spm-1 metallo-β-lactamase are modulated by second sphere residues
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3879351/
https://www.ncbi.nlm.nih.gov/pubmed/24391494
http://dx.doi.org/10.1371/journal.ppat.1003817
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