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Structural features of Chi recognition in AddAB with implications for RecBCD.

ABSTRACT: AddAB and RecBCD-type helicase-nuclease complexes control the first stage of bacterial homologous recombination (HR) - the resection of double strand DNA breaks. A switch in the activities of the complexes to initiate repair by HR is regulated by a short, species-specific DNA sequence known as a Crossover Hotspot Instigator (Chi) site. It has been shown that, upon encountering Chi, AddAB and RecBCD pause translocation before resuming at a reduced rate. Recently, the structure of B.subtilis AddAB in complex with its regulatory Chi sequence revealed the nature of Chi binding and the paused translocation state. Here the structural features associated with Chi binding are described in greater detail and discussed in relation to the related E.coli RecBCD system.

SUBMITTER: Wilkinson M

PROVIDER: S-EPMC4614115 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Structural features of Chi recognition in AddAB with implications for RecBCD.

Wilkinson Martin M Wigley Dale B DB

Cell cycle (Georgetown, Tex.) 20140101 18

AddAB and RecBCD-type helicase-nuclease complexes control the first stage of bacterial homologous recombination (HR) - the resection of double strand DNA breaks. A switch in the activities of the complexes to initiate repair by HR is regulated by a short, species-specific DNA sequence known as a Crossover Hotspot Instigator (Chi) site. It has been shown that, upon encountering Chi, AddAB and RecBCD pause translocation before resuming at a reduced rate. Recently, the structure of B.subtilis AddAB ...[more]

PMID: 25486468

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RecBCD Enzyme "Chi Recognition" Mutants Recognize Chi Recombination Hotspots in the Right DNA Context.

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RecBCD enzyme switches lead motor subunits in response to chi recognition.

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