Oyama T, Ishino Y, Cann I K, Ishino S, Morikawa K
Department of Structural Biology and, Biomolecular Engineering Research Institute, 6-2-3 Furuedai, Suita-City, 565-0874, Osaka, Japan.
Mol Cell. 2001 Aug;8(2):455-63. doi: 10.1016/s1097-2765(01)00328-8.
In eukaryotic DNA replication, replication factor-C (RFC) acts as the clamp loader, which correctly installs the sliding clamp onto DNA strands at replication forks. The eukaryotic RFC is a complex consisting of one large and four small subunits. We have determined the crystal structure of the clamp loader small subunit (RFCS) from Pyrococcus furiosus. The six subunits, of which four bind ADP in their canonical nucleotide binding clefts, assemble into a dimer of semicircular trimers. The crescent-like architecture of each subunit formed by the three domains resembles that of the delta' subunit of the E. coli clamp loader. The trimeric architecture of archaeal RFCS, with its mobile N-terminal domains, involves intersubunit interactions that may be conserved in eukaryotic functional complexes.
在真核生物DNA复制过程中，复制因子C（RFC）充当夹子加载器，它能在复制叉处将滑动夹子正确地安装到DNA链上。真核生物RFC是一个由一个大亚基和四个小亚基组成的复合体。我们已经确定了嗜热栖热菌夹子加载器小亚基（RFCS）的晶体结构。六个亚基（其中四个在其典型的核苷酸结合裂隙中结合ADP）组装成一个半圆形三聚体的二聚体。由三个结构域形成的每个亚基的新月形结构类似于大肠杆菌夹子加载器的δ'亚基。古菌RFCS的三聚体结构及其可移动的N端结构域涉及亚基间相互作用，这种相互作用可能在真核生物功能复合体中保守。
