Functional characterization of two SOS-regulated genes involved in mitomycin C resistance in Caulobacter crescentus.
DNA Repair (Amst)
; 33: 78-89, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26162909
The SOS response is a universal bacterial regulon involved in the cellular response to DNA damage and other forms of stress. In Caulobacter crescentus, previous work has identified a plethora of genes that are part of the SOS regulon, but the biological roles of several of them remain to be determined. In this study, we report that two genes, hereafter named mmcA and mmcB, are involved in the defense against DNA damage caused by mitomycin C (MMC), but not against lesions induced by other common DNA damaging agents, such as UVC light, methyl methanesulfonate (MMS) and hydrogen peroxide. mmcA is a conserved gene that encodes a member of the glyoxalases/dioxygenases protein family, and acts independently of known DNA repair pathways. On the other hand, epistasis analysis showed that mmcB acts in the same pathway as imuC (dnaE2), and is required specifically for MMC-induced mutagenesis, but not for that induced by UV light, suggesting a role for MmcB in translesion synthesis-dependent repair of MMC damage. We show that the lack of MMC-induced mutability in the mmcB strain is not caused by lack of proper SOS induction of the imuABC operon, involved in translesion synthesis (TLS) in C. crescentus. Based on this data and on structural analysis of a close homolog, we propose that MmcB is an endonuclease which creates substrates for ImuABC-mediated TLS patches.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Resposta SOS em Genética
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Mitomicina
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Caulobacter crescentus
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Genes Bacterianos
Idioma:
En
Revista:
DNA Repair (Amst)
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda