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Cleavage mechanism of human Mus81-Eme1 acting on Holliday-junction structures.

ABSTRACT: Recombination-mediated repair plays a central role in maintaining genomic integrity during DNA replication. The human Mus81-Eme1 endonuclease is involved in recombination repair, but the exact structures it acts on in vivo are not known. Using kinetic and enzymatic analysis of highly purified recombinant enzyme, we find that Mus81-Eme1 catalyzes coordinate bilateral cleavage of model Holliday-junction structures. Using a self-limiting, cruciform-containing substrate, we demonstrate that bilateral cleavage occurs sequentially within the lifetime of the enzyme-substrate complex. Coordinate bilateral cleavage is promoted by the highly cooperative nature of the enzyme and results in symmetrical cleavage of a cruciform structure, thus, Mus81-Eme1 can ensure coordinate, bilateral cleavage of Holliday junction-like structures.

SUBMITTER: Taylor ER

PROVIDER: S-EPMC2268786 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature

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Cleavage mechanism of human Mus81-Eme1 acting on Holliday-junction structures.

Taylor Ewan R ER McGowan Clare H CH

Proceedings of the National Academy of Sciences of the United States of America 20080229 10

Recombination-mediated repair plays a central role in maintaining genomic integrity during DNA replication. The human Mus81-Eme1 endonuclease is involved in recombination repair, but the exact structures it acts on in vivo are not known. Using kinetic and enzymatic analysis of highly purified recombinant enzyme, we find that Mus81-Eme1 catalyzes coordinate bilateral cleavage of model Holliday-junction structures. Using a self-limiting, cruciform-containing substrate, we demonstrate that bilatera ...[more]

PMID: 18310322

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Regulation of Mus81-Eme1 Holliday junction resolvase in response to DNA damage.

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Human Rad54 protein stimulates human Mus81-Eme1 endonuclease.

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Crystal structure of the Mus81-Eme1 complex.

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