2007 Volume 76 Issue 3 Pages 3_129-3_135
Replication protein A (Rpa) is a heterotrimeric protein complex, composed of three tightly associated subunits of RPA70 (Rpa1), RPA32 (Rpa2) and RPA14 (Rpa3) in the case of human cells. The Rpa is known to be required for almost all aspects of cellular DNA metabolism. In the present study, we isolated and characterized the cDNAs orthologous to the Homo sapience RPA2 and RPA3, BmRPA2 and BmRPA3, respectively, from the silkworm, Bombyx mori. Each gene has a single conserved OB-fold domain. Although there was a higher level of homology among Rpa2s from different species, those of Rpa3s were very low. Furthermore, the analysis using yeast two-hybrid system revealed that the BmRpa2 and BmRpa3 form a tight heterotrimeric complex with BmRpa1. In addition, we confirmed the silkworm Rpa complex binds single-stranded DNA, but not double-stranded DNA.
