probe more firmly if a longer region of homology exists. However, with Dmc1 a triplet with a single internal (but not terminal) mismatch will contribute to the stability of probe binding to a similar extent as one without a mismatch. In this way, Dmc1 is specially suited to its role as a meiosis-specific recombinase, as this activity permits it more effectively to catalyze recombination between sequences that are not perfectly matched. Interactions DMC1 (gene) has been shown to interact with RAD51. The protein has also been shown to bind Tid1(Rdh54), Mei5/Sae3, and Hop2/Mnd1. All of these interacting proteins act to enhance Dmc1's activity in purified systems and are also implicated as being required for Dmc1 function in cells. Rad51 interaction with Dmc1 During meiosis, the two recombinases, Rad51 and Dmc1, interact with single-stranded DNA to form specialized filaments that are adapted for facilitating recombination between homologous chromosomes. Both Dmc1 and Rad51 have an intrinsic ability to self-aggregate. The presence of Rad51 filaments stabilizes adjacent Dmc1 filaments and conversely Dmc1 stabilizes adjacent Rad51 filaments. A model was proposed in which Dmc1 and Rad51 form separate filaments on the same single stranded DNA and cross-talk between the two recombinases affects their biochemical properties. During meiosis, even in the absence of Rad51 strand exchange activity, Dmc1 appears to be able to repair all meiotic DNA breaks, and this absence does not affect meiotic crossing over rates. References Further reading Genes on human chromosome 22