Fuse or die: how to survive the loss of Dam in Vibrio cholerae.
Mol Microbiol
; 91(4): 665-78, 2014 Feb.
Article
em En
| MEDLINE
| ID: mdl-24308271
ABSTRACT
Dam methylates GATC sequences in γ-proteobacteria genomes, regulating several cellular functions including replication. In Vibrio cholerae, which has two chromosomes, Dam is essential for viability, owing to its role in chr2 replication initiation. In this study, we isolated spontaneous mutants of V. cholerae that were able to survive the deletion of dam. In these mutants, homologous recombination and chromosome dimer resolution are essential, unless DNA mismatch repair is inactivated. Furthermore, the initiator of chr2 replication, RctB, is no longer required. We show that, instead, replication of chr2 is insured by spontaneous fusion with chr1 and piggybacking its replication machinery. We report that natural fusion of chr1 and chr2 occurred by two distinct recombination pathways homologous recombination between repeated IS elements and site-specific recombination between dif sites. Lastly, we observed a preferential fusion of the two chromosomes in their terminus of replication.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Recombinação Genética
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Vibrio cholerae
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DNA Metiltransferases Sítio Específica (Adenina-Específica)
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Regulação Bacteriana da Expressão Gênica
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Viabilidade Microbiana
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
França