Gary S L, Burgers M J
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
Nucleic Acids Res. 1995 Dec 25;23(24):4986-91. doi: 10.1093/nar/23.24.4986.
Yeast replication factor C (RF-C) is a multipolypeptide complex required for chromosomal DNA replication. Previously this complex was known to consist of at least four subunits. We here report the identification of a fifth RF-C subunit from Saccharomyces cerevisiae, encoded by the RFC5 (YBR0810) gene. This subunit exhibits highest homology to the 38 kDa subunit (38%) of human RF-C (activator 1). Like the other four RFC genes, the RFC5 gene is essential for yeast viability, indicating an essential function for each subunit. RFC5 mRNA is expressed at steady-state levels throughout the mitotic cell cycle. Upon overexpression in Escherichia coli Rfc5p has an apparent molecular mass of 41 kDa. Overproduction of RF-C activity in yeast is dependent on overexpression of the RFC5 gene together with overexpression of the RFC1-4 genes, indicating that the RFC5 gene product forms an integral subunit of this replication factor.
酵母复制因子C（RF-C）是染色体DNA复制所需的一种多亚基复合物。此前已知该复合物至少由四个亚基组成。我们在此报告从酿酒酵母中鉴定出第五个RF-C亚基，由RFC5（YBR0810）基因编码。该亚基与人类RF-C（激活因子1）的38 kDa亚基具有最高的同源性（38%）。与其他四个RFC基因一样，RFC5基因对酵母的生存能力至关重要，这表明每个亚基都具有重要功能。RFC5 mRNA在整个有丝分裂细胞周期中以稳定状态水平表达。在大肠杆菌中过表达时，Rfc5p的表观分子量为41 kDa。酵母中RF-C活性的过量产生依赖于RFC5基因与RFC1-4基因的共同过表达，这表明RFC5基因产物形成了该复制因子的一个完整亚基。
