Replication protein A

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Replication protein A C terminal
Symbol RPA_C
Pfam PF08784
InterPro IPR014892

Replication protein A (RPA) is a protein that binds to single-stranded DNA in eukaryotic cells.[1] During DNA replication, RPA prevents single-stranded DNA (ssDNA) from winding back on itself or from forming secondary structures. This keeps DNA unwound for the polymerase to replicate it. RPA also binds to ssDNA during the initial phase of homologous recombination, an important process in DNA repair and prophase I of meiosis. Hypersensitivity to DNA damaging agents can be caused by mutations in the RPA gene.[2] Like its role in DNA replication, this keeps ssDNA from binding to itself (self-complementizing) so that the resulting nucleoprotein filament can then be bound by Rad51 and its cofactors.[3] RPA also binds to DNA during the Nucleotide Excision Repair process. This binding stabilizes the repair complex during the repair process. A bacterial homolog is called single-strand binding protein (SSB).


RPA is a heterotrimer, composed of the subunits RPA1 (70kDa subunit), RPA2 (32kDa subunit) and RPA3 (14kDa subunit). The three RPA subunits contain OB-folds (oligonucleotide/oligosaccharide binding).


  1. ^ Wold, MS (1997). "Replication protein A: heterotrimeric, single-stranded DNA-binding protein required for eukaryotic DNA metabolism". Annual Review of Biochemistry 66 (1): 61–92. doi:10.1146/annurev.biochem.66.1.61. PMID 9242902. 
  2. ^ Zou, Yue; Liu, Yiyong; Wu, Xiaoming; Shell, Steven M. (2006-08-01). "Functions of human replication protein A (RPA): from DNA replication to DNA damage and stress responses". Journal of Cellular Physiology 208 (2): 267–273. doi:10.1002/jcp.20622. ISSN 0021-9541. PMC 3107514. PMID 16523492. 
  3. ^ Xuan, L; Wolf-Dietrich, H (2008). "Homologous recombination in DNA repair and DNA damage tolerance". Cell Research 18 (99): 99–113. doi:10.1038/cr.2008.1. PMC 3087377. PMID 18166982.