Nasheuer H P, von Winkler D, Schneider C, Dornreiter I, Gilbert I, Fanning E
Institute for Biochemistry, LMU München, Federal Republic of Germany.
Chromosoma. 1992;102(1 Suppl):S52-9. doi: 10.1007/BF02451786.
The single-stranded DNA binding protein RP-A is required in SV40 DNA in vitro replication. The RP-A purified from calf thymus contains 4 polypeptides with molecular weights 70kDa, 53kDa, 32kDa, and 14kDa. The p70 subunit and its proteolysed form p53 are recognized by the monoclonal antibody 70C (Kenny et al. (1990)) and bind to ssDNA. The p70 and p32 subunits of bovine RP-A are phosphorylated by CDC2-cyclin B kinase. Bovine RP-A supports the origin dependent unwinding of SV40 DNA by T antigen. Furthermore, bovine RP-A can efficiently substitute for human RP-A in SV40 DNA replication in vitro. A modified blotting technique revealed that RP-A interacts specifically and directly with the p48 subunit of DNA polymerase alpha-primase complex.
单链DNA结合蛋白RP-A是SV40 DNA体外复制所必需的。从小牛胸腺纯化的RP-A含有4种分子量分别为70kDa、53kDa、32kDa和14kDa的多肽。p70亚基及其经蛋白酶水解的形式p53可被单克隆抗体70C识别（肯尼等人，1990年），并与单链DNA结合。牛RP-A的p70和p32亚基被CDC2-细胞周期蛋白B激酶磷酸化。牛RP-A支持T抗原对SV40 DNA的依赖于起始点的解旋。此外，在体外SV40 DNA复制中，牛RP-A可以有效地替代人RP-A。一种改良的印迹技术表明，RP-A与DNA聚合酶α-引发酶复合物的p48亚基特异性且直接相互作用。
