Cullmann G, Fien K, Kobayashi R, Stillman B
Cold Spring Harbor Laboratory, New York 11724, USA.
Mol Cell Biol. 1995 Sep;15(9):4661-71. doi: 10.1128/MCB.15.9.4661.
Replication factor C (RFC) is a five-subunit DNA polymerase accessory protein that functions as a structure-specific, DNA-dependent ATPase. The ATPase function of RFC is activated by proliferating cell nuclear antigen. RFC was originally purified from human cells on the basis of its requirement for simian virus 40 DNA replication in vitro. A functionally homologous protein complex from Saccharomyces cerevisiae, called ScRFC, has been identified. Here we report the cloning, by either peptide sequencing or by sequence similarity to the human cDNAs, of the S. cerevisiae genes RFC1, RFC2, RFC3, RFC4, and RFC5. The amino acid sequences are highly similar to the sequences of the homologous human RFC 140-, 37-, 36-, 40-, and 38-kDa subunits, respectively, and also show amino acid sequence similarity to functionally homologous proteins from Escherichia coli and the phage T4 replication apparatus. All five subunits show conserved regions characteristic of ATP/GTP-binding proteins and also have a significant degree of similarity among each other. We have identified eight segments of conserved amino acid sequences that define a family of related proteins. Despite their high degree of sequence similarity, all five RFC genes are essential for cell proliferation in S. cerevisiae. RFC1 is identical to CDC44, a gene identified as a cell division cycle gene encoding a protein involved in DNA metabolism. CDC44/RFC1 is known to interact genetically with the gene encoding proliferating cell nuclear antigen, confirming previous biochemical evidence of their functional interaction in DNA replication.
复制因子C（RFC）是一种由五个亚基组成的DNA聚合酶辅助蛋白，作为一种结构特异性的、依赖DNA的ATP酶发挥作用。RFC的ATP酶功能由增殖细胞核抗原激活。RFC最初是根据其在体外对猿猴病毒40 DNA复制的需求从人细胞中纯化出来的。已鉴定出酿酒酵母中一种功能同源的蛋白质复合物，称为ScRFC。在这里，我们报告了通过肽测序或与人类cDNA的序列相似性克隆酿酒酵母基因RFC1、RFC2、RFC3、RFC4和RFC5。其氨基酸序列分别与同源的人类RFC 140 kDa、37 kDa、36 kDa、40 kDa和38 kDa亚基的序列高度相似，并且与来自大肠杆菌和噬菌体T4复制装置的功能同源蛋白也显示出氨基酸序列相似性。所有五个亚基都显示出ATP/GTP结合蛋白特有的保守区域，并且彼此之间也有显著程度的相似性。我们已经鉴定出八个保守氨基酸序列片段，它们定义了一个相关蛋白家族。尽管这五个RFC基因的序列相似度很高，但它们对酿酒酵母的细胞增殖都是必不可少的。RFC1与CDC44相同，CDC44是一个被鉴定为细胞分裂周期基因，编码一种参与DNA代谢的蛋白质。已知CDC44/RFC1与编码增殖细胞核抗原的基因发生遗传相互作用，这证实了它们在DNA复制中功能相互作用的先前生化证据。
