State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Danish Archaea Centre, Department of Biology, Copenhagen University, Copenhagen, Denmark.
J Bacteriol. 2014 Jul;196(13):2367-75. doi: 10.1128/JB.01552-14. Epub 2014 Apr 18.
Replication factor C (RFC) is known to function in loading proliferating cell nuclear antigen (PCNA) onto primed DNA, allowing PCNA to tether DNA polymerase for highly processive DNA synthesis in eukaryotic and archaeal replication. In this report, we show that an RFC complex from the hyperthermophilic archaea of the genus Sulfolobus physically interacts with DNA polymerase B1 (PolB1) and enhances both the polymerase and 3'-5' exonuclease activities of PolB1 in an ATP-independent manner. Stimulation of the PolB1 activity by RFC is independent of the ability of RFC to bind DNA but is consistent with the ability of RFC to facilitate DNA binding by PolB1 through protein-protein interaction. These results suggest that Sulfolobus RFC may play a role in recruiting DNA polymerase for efficient primer extension, in addition to clamp loading, during DNA replication.
复制因子 C（RFC）已知在加载增殖细胞核抗原（PCNA）到引发的 DNA 上起作用，允许 PCNA 将 DNA 聚合酶固定在 DNA 上，从而在真核生物和古菌的复制中进行高持续性的 DNA 合成。在本报告中，我们表明，来自嗜热古菌属 Sulfolobus 的 RFC 复合物与 DNA 聚合酶 B1（PolB1）物理相互作用，并以 ATP 非依赖性的方式增强 PolB1 的聚合酶和 3'-5'外切核酸酶活性。RFC 对 PolB1 活性的刺激与 RFC 结合 DNA 的能力无关，但与 RFC 通过蛋白-蛋白相互作用促进 PolB1 结合 DNA 的能力一致。这些结果表明，Sulfolobus RFC 可能除了加载夹之外，在 DNA 复制过程中还在招募 DNA 聚合酶以进行有效的引物延伸中发挥作用。
