Involved in DNA mismatch repair and meiotic recombination processes. Facilitates crossovers between homologs during meiosis (By similarity). Heterooligomer of MSH4 and MSH5. Interacts with HJURP. Widely expressed, with high levels in testis and ovary, including granulosa cells (PubMed:9740671, PubMed:28175301). Also expressed in fetal ovary and adrenal gland (PubMed:28175301). The disease is caused by variants affecting the gene represented in this entry. Belongs to the DNA mismatch repair MutS family.