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Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44

A genomic analysis of Comamonas testosteroni S44 revealed a gene that encodes a LysR family transcriptional regulator (here named czoR, czo for cefazolin) located upstream of a putative class A β-lactamase encoding gene (here named czoA). A putative DNA-binding motif of the Fe–S cluster assembly reg...

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Autores principales: Zhuang, Weiping, Liu, Hongliang, Li, Jingxin, Chen, Lu, Wang, Gejiao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5744064/
https://www.ncbi.nlm.nih.gov/pubmed/29312251
http://dx.doi.org/10.3389/fmicb.2017.02573
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author Zhuang, Weiping
Liu, Hongliang
Li, Jingxin
Chen, Lu
Wang, Gejiao
author_facet Zhuang, Weiping
Liu, Hongliang
Li, Jingxin
Chen, Lu
Wang, Gejiao
author_sort Zhuang, Weiping
collection PubMed
description A genomic analysis of Comamonas testosteroni S44 revealed a gene that encodes a LysR family transcriptional regulator (here named czoR, czo for cefazolin) located upstream of a putative class A β-lactamase encoding gene (here named czoA). A putative DNA-binding motif of the Fe–S cluster assembly regulator IscR was identified in the czoR–czoA intergenic region. Real-time RT-PCR and lacZ fusion expression assays indicated that transcription of czoA and czoR were induced by multiple β-lactams. CzoA expressed in Escherichia coli was shown to contribute to susceptibility to a wide range of β-lactams judged from minimum inhibitory concentrations. In vitro enzymatic assays showed that CzoA hydrolyzed seven β-lactams, including benzylpenicillin, ampicillin, cefalexin, cefazolin, cefuroxime, ceftriaxone, and cefepime. Deletion of either iscR or czoR increased susceptibility to cefalexin and cefazolin, while complemented strains restored their wild-type susceptibility levels. Electrophoretic mobility shift assays (EMSA) demonstrated that CzoR and IscR bind to different sites of the czoR–czoA intergenic region. Precise CzoR- and IscR-binding sites were confirmed via DNase I footprinting or short fragment EMSA. When cefalexin or cefazolin was added to cultures, czoR deletion completely inhibited czoA expression but did not affect iscR transcription, while iscR deletion decreased the expressions of both czoR and czoA. These results reveal that CzoR positively affects the expression of czoA with its own expression upregulated by IscR.
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spelling pubmed-57440642018-01-08 Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44 Zhuang, Weiping Liu, Hongliang Li, Jingxin Chen, Lu Wang, Gejiao Front Microbiol Microbiology A genomic analysis of Comamonas testosteroni S44 revealed a gene that encodes a LysR family transcriptional regulator (here named czoR, czo for cefazolin) located upstream of a putative class A β-lactamase encoding gene (here named czoA). A putative DNA-binding motif of the Fe–S cluster assembly regulator IscR was identified in the czoR–czoA intergenic region. Real-time RT-PCR and lacZ fusion expression assays indicated that transcription of czoA and czoR were induced by multiple β-lactams. CzoA expressed in Escherichia coli was shown to contribute to susceptibility to a wide range of β-lactams judged from minimum inhibitory concentrations. In vitro enzymatic assays showed that CzoA hydrolyzed seven β-lactams, including benzylpenicillin, ampicillin, cefalexin, cefazolin, cefuroxime, ceftriaxone, and cefepime. Deletion of either iscR or czoR increased susceptibility to cefalexin and cefazolin, while complemented strains restored their wild-type susceptibility levels. Electrophoretic mobility shift assays (EMSA) demonstrated that CzoR and IscR bind to different sites of the czoR–czoA intergenic region. Precise CzoR- and IscR-binding sites were confirmed via DNase I footprinting or short fragment EMSA. When cefalexin or cefazolin was added to cultures, czoR deletion completely inhibited czoA expression but did not affect iscR transcription, while iscR deletion decreased the expressions of both czoR and czoA. These results reveal that CzoR positively affects the expression of czoA with its own expression upregulated by IscR. Frontiers Media S.A. 2017-12-22 /pmc/articles/PMC5744064/ /pubmed/29312251 http://dx.doi.org/10.3389/fmicb.2017.02573 Text en Copyright © 2017 Zhuang, Liu, Li, Chen and Wang. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Zhuang, Weiping
Liu, Hongliang
Li, Jingxin
Chen, Lu
Wang, Gejiao
Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title_full Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title_fullStr Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title_full_unstemmed Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title_short Regulation of Class A β-Lactamase CzoA by CzoR and IscR in Comamonas testosteroni S44
title_sort regulation of class a β-lactamase czoa by czor and iscr in comamonas testosteroni s44
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5744064/
https://www.ncbi.nlm.nih.gov/pubmed/29312251
http://dx.doi.org/10.3389/fmicb.2017.02573
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