Bunz F, Kobayashi R, Stillman B
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724.
Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):11014-8. doi: 10.1073/pnas.90.23.11014.
Replication factor C (RFC) is a multisubunit, DNA polymerase accessory protein required for the coordinated synthesis of both DNA strands during simian virus 40 DNA replication in vitro. Previous studies have shown that RFC is a DNA-dependent ATPase that binds in a structure-specific manner to the 3' end of a primer hybridized to a template DNA, an activity thought intrinsic to the 140-kDa component of this multisubunit complex. Here, the isolation and analysis of cDNAs encoding this subunit is described. Analysis of the full-length coding sequence revealed an open reading frame of 3.4 kb, encoding an 1148-amino acid protein with a predicted molecular mass of 130 kDa. A putative ATP-binding motif was observed that is similar to a motif in several of the smaller subunits of RFC and in functionally homologous replication factors of bacterial and viral origin. A "DEAD" box is also conserved among these proteins. The predicted protein shows significant identity with a DNA-binding protein of murine origin (B. Luckow, P. Lichter, and G. Schütz, personal communication). Regions of similarity were also seen between the amino acid sequences of the 140-kDa subunit of RFC, poly(ADP-ribose) polymerase, and bacterial DNA ligases--possibly representing a conserved structural feature of these proteins that bind similar DNA substrates.
复制因子C（RFC）是一种多亚基DNA聚合酶辅助蛋白，在体外猿猴病毒40 DNA复制过程中，对于两条DNA链的协同合成是必需的。先前的研究表明，RFC是一种依赖DNA的ATP酶，它以结构特异性方式结合到与模板DNA杂交的引物的3'末端，这种活性被认为是该多亚基复合物140-kDa组分所固有的。本文描述了编码该亚基的cDNA的分离和分析。对全长编码序列的分析揭示了一个3.4 kb的开放阅读框，编码一个1148个氨基酸的蛋白质，预测分子量为130 kDa。观察到一个推定的ATP结合基序，它类似于RFC几个较小亚基以及细菌和病毒来源的功能同源复制因子中的一个基序。在这些蛋白质中还保守着一个“DEAD”框。预测的蛋白质与鼠源DNA结合蛋白有显著的同源性（B. Luckow、P. Lichter和G. Schütz，个人交流）。在RFC 140-kDa亚基、聚（ADP-核糖）聚合酶和细菌DNA连接酶的氨基酸序列之间也发现了相似区域——可能代表了这些结合相似DNA底物的蛋白质的保守结构特征。
