REPLICATION PROTEIN-A - A HETEROTRIMERIC, SINGLE-STRANDED DNA-BINDINGPROTEIN REQUIRED FOR EUKARYOTIC DNA METABOLISM

Replication protein A [RPA; also known as replication factor A (RFA) a nd human single-stranded DNA-binding protein] is a single-stranded DNA -binding protein that is required for multiple processes in eukaryotic DNA metabolism, including DNA replication, DNA repair, and recombinat ion. RPA homologues have been identified in all eukaryotic organisms e xamined and are all abundant heterotrimeric proteins composed of subun its of approximately 70, 30, and 14 kDa. Members of this family bind n onspecifically to single-stranded DNA and interact with and/or modify the activities of multiple proteins. In cells, RPA is phosphorylated b y DNA-dependent protein kinase when RPA is bound to single-stranded DN A (during S phase and after DNA damage). Phosphorylation of RPA may pl ay a role in coordinating DNA metabolism in the cell. RPA may also hav e a role in modulating gene expression.