The Mus81-Mms4 structure-selective endonuclease requires nicked DNA junctions to undergo conformational changes and bend its DNA substrates for cleavage.

ABSTRACT: Mus81-Mms4/EME1 is a DNA structure-selective endonuclease that cleaves joint DNA molecules that form during homologous recombination in mitotic and meiotic cells. Here, we demonstrate by kinetic analysis using physically tethered DNA substrates that budding yeast Mus81-Mms4 requires inherent rotational flexibility in DNA junctions for optimal catalysis. Förster Resonance Energy Transfer experiments further reveal that recognition of 3'-flap and nicked Holliday junction substrates by Mus81-Mms4 involves induction of a sharp bend with a 100° angle between two duplex DNA arms. In addition, thiol crosslinking of Mus81-Mms4 bound to DNA junctions demonstrates that the heterodimer undergoes a conformational change induced by joint DNA molecules with preferred structural properties. The results f

SUBMITTER: Mukherjee S 

PROVIDER: S-EPMC4041439 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature