InterPro domain: IPR033309

Budding yeast Mus81 complexes with Mms4 (EME1 or EME2 in humans) to form a structure-specific endonuclease that targets branched DNA structures with a 5'-end at the branch nick [ 1 , 2 ]. Its typical substrates include 3'-flap structures, replication forks and nicked Holliday junctions [ 3 , 4 ].

Similar to MUS81-EME1, human MUS81-EME2 cleaves 3'-flaps, replication forks and nicked Holliday junctions, and exhibits limited endonuclease activity with intact Holliday junctions. However, MUS81-EME2 can also cleave a variety of DNA structures including D-loop recombination intermediates and nicked duplex [ 5 , 6 ].

1. Functional domains required for the Saccharomyces cerevisiae Mus81-Mms4 endonuclease complex formation and nuclear localization. DNA Repair (Amst.) 2, 1435-47
2. Human MUS81 complexes stimulate flap endonuclease 1. FEBS J. 279, 2412-30
3. DNA REPAIR. Mus81 and converging forks limit the mutagenicity of replication fork breakage. Science 349, 742-7
4. Mus81 cleavage of Holliday junctions: a failsafe for processing meiotic recombination intermediates? EMBO J. 26, 1891-901
5. Substrate specificity of the MUS81-EME2 structure selective endonuclease. Nucleic Acids Res. 42, 3833-45
6. Human MUS81-EME2 can cleave a variety of DNA structures including intact Holliday junction and nicked duplex. Nucleic Acids Res. 42, 5846-62