This family includes a conserved region from the Mus7 protein [1]. Mus7 is involved in the repair of replication-associated DNA damage in the fission yeast Schizosaccharomyces pombe. Mus7 functions in the same pathway as Mus81, a subunit of the Mus81-Eme1 structure-specific endonuclease, which has been implicated in the repair of the replication-associated DNA damage [1]. The MMS22 proteins are involved in repairing double-stranded DNA breaks created by the cleavage reaction of topoisomerase II [2].

1: The novel gene mus7(+) is involved in the repair of replication-associated DNA damage in fission yeast. Yokoyama M, Inoue H, Ishii C, Murakami Y; DNA Repair (Amst). 2007;0:0-1. PMID:17307401

2: Mms22p protects Saccharomyces cerevisiae from DNA damage induced by topoisomerase II. Baldwin EL, Berger AC, Corbett AH, Osheroff N; Nucleic Acids Res 2005;33:1021-1030. PMID:15718301