Cloning and characterization of replication protein A p32 complementary DNA in zebrafish (Danio rerio)

Replication protein A (RPA) is a heterotrimeric single-stranded DNA-binding protein (70, 32, and 14 kDa) that is an essential component of the DNA replication fork. A complementary DNA encoding zebrafish RPA 32-kDa subunit was isolated by screening a zebrafish embryo lambda APII cDNA library with a human RPA p32 cDNA probe. The zebrafish RPA p32 cDNA consisted of 1097 bp encoding 272 amino acid residues. The deduced amino acid sequence shows high similarity to mouse and human RPA p32. In vitro phosphorylation of zebrafish RPA protein by Cdc2 kinase was shown. A recombinant protein of zebrafish RPA p32 containing a short histidine tag at the NH(2)-terminus was overexpressed in Escherichia coli BL21(DE3) pLys using an inducible T7 expression system, and was purified by Ni-NTA affinity chromatography. In this article, cloning of the zebrafish RPA p32 cDNA is reported in relation to the study of DNA replication in fish.