ISOLATION AND CHARACTERIZATION OF RAD51C, A NEW HUMAN MEMBER OF THE RAD51 FAMILY OF RELATED GENES

The yeast and human RAD51 genes encode strand-transfer proteins that a re thought to be involved in both recombinational repair of DNA damage and meiotic recombination, In yeast, the Rad51 family of related prot eins also includes Rad55, Rad57 and Dmc1, In mammalian cells, five gen es in this family have been identified (HsRAD51, XRCC2, XRCC3, RAD41B/ hREC2 and HsDMC1), and here we report the isolation of the sixth membe r, RAD51C, RAD51C was originally identified by a computer screen of th e EST database, A full-length similar to 1.3 kb cDNA clone has been is olated that encodes a protein of 376 aa, having a 18-26% aa identity w ith other human Rad51 family members. RAD51C includes a previously map ped sequenced-tagged site location near the end of chromosome 17q. The RAD51C transcript is expressed in various human tissues, with highest level of expression in testis, followed by heart muscle, spleen and p rostate, Yeast two-hybrid experiments indicate that the Rad51C protein binds to two other members of the Rad51 protein family (Xrcc3 and Rad 51B) but not to itself, These findings suggest that Rad51C may functio n similarly to the yeast Rad55 or Rad57 proteins, rather than as a Rad 51 functional homolog.