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Single-molecule studies reveal the function of a third polymerase in the replisome.

ABSTRACT: The Escherichia coli replisome contains three polymerases, one more than necessary to duplicate the two parental strands. Using single-molecule studies, we reveal two advantages conferred by the third polymerase. First, dipolymerase replisomes are inefficient at synthesizing lagging strands, leaving single-strand gaps, whereas tripolymerase replisomes fill strands almost to completion. Second, tripolymerase replisomes are much more processive than dipolymerase replisomes. These features account for the unexpected three-polymerase-structure of bacterial replisomes.

SUBMITTER: Georgescu RE

PROVIDER: S-EPMC3721970 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

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Single-molecule studies reveal the function of a third polymerase in the replisome.

Georgescu Roxana E RE Kurth Isabel I O'Donnell Mike E ME

Nature structural & molecular biology 20111211 1

The Escherichia coli replisome contains three polymerases, one more than necessary to duplicate the two parental strands. Using single-molecule studies, we reveal two advantages conferred by the third polymerase. First, dipolymerase replisomes are inefficient at synthesizing lagging strands, leaving single-strand gaps, whereas tripolymerase replisomes fill strands almost to completion. Second, tripolymerase replisomes are much more processive than dipolymerase replisomes. These features account ...[more]

PMID: 22157955

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