Localization of an accessory helicase at the replisome is critical in sustaining efficient genome duplication.
Nucleic Acids Res
; 39(3): 949-57, 2011 Feb.
Article
em En
| MEDLINE
| ID: mdl-20923786
ABSTRACT
Genome duplication requires accessory helicases to displace proteins ahead of advancing replication forks. Escherichia coli contains three helicases, Rep, UvrD and DinG, that might promote replication of protein-bound DNA. One of these helicases, Rep, also interacts with the replicative helicase DnaB. We demonstrate that Rep is the only putative accessory helicase whose absence results in an increased chromosome duplication time. We show also that the interaction between Rep and DnaB is required for Rep to maintain rapid genome duplication. Furthermore, this Rep-DnaB interaction is critical in minimizing the need for both recombinational processing of blocked replication forks and replisome reassembly, indicating that colocalization of Rep and DnaB minimizes stalling and subsequent inactivation of replication forks. These data indicate that E. coli contains only one helicase that acts as an accessory motor at the fork in wild-type cells, that such an activity is critical for the maintenance of rapid genome duplication and that colocalization with the replisome is crucial for this function. Given that the only other characterized accessory motor, Saccharomyces cerevisiae Rrm3p, associates physically with the replisome, our demonstration of the functional importance of such an association indicates that colocalization may be a conserved feature of accessory replicative motors.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA Helicases
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Proteínas de Escherichia coli
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DNA Polimerase Dirigida por DNA
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Replicação do DNA
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Escherichia coli
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DnaB Helicases
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Complexos Multienzimáticos
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Reino Unido