Linear diffusion on DNA despite high-affinity binding by a DNA polymerase processivity factor.
Linear diffusion on DNA despite high-affinity binding by a DNA polymerase processivity factor.
复制标题
尽管 DNA 聚合酶持续因子具有高亲和力结合，但 DNA 上仍呈线性扩散。
DOI：
10.1016/s1097-2765(01)00355-0
复制
发表时间：
2001
期刊：
影响因子：
16
通讯作者：
Coen,DM
中科院分区：
文献类型：
--
作者：
Randell,JC;Coen,DM
寡聚体的“滑动钳”持续合成因子，如PCNA，被认为依赖于与DNA的松散的拓扑学关联来沿着dsDNA自由滑动。与PCNA不同，单纯疱疹病毒DNA聚合酶的持续合成能力亚基UL 42是单体，并且对dsDNA具有固有的亲和力，其对于序列独立的DNA结合蛋白而言非常高。使用DNA酶足迹法测定，我们证明，UL 42易位与催化亚基的聚合酶在链延伸。此外，足迹法和电泳迁移率变动分析表明，尽管其紧密的DNA结合，UL 42能够以17和47 bp/s之间的速率在DNA上线性扩散。因此，我们的研究结果表明，尽管深刻的生化差异与滑动夹，UL 42可以自由地滑动下游的催化亚基在DNA复制。
The oligomeric "sliding clamp" processivity factors, such as PCNA, are thought to rely on a loose, topological association with DNA to slide freely along dsDNA. Unlike PCNA, the processivity subunit of the herpes simplex virus DNA polymerase, UL42, is a monomer and has an intrinsic affinity for dsDNA that is remarkably high for a sequence-independent DNA binding protein. Using a DNase footprinting assay, we demonstrate that UL42 translocates with the catalytic subunit of the polymerase during chain elongation. In addition, footprinting and electrophoretic mobility shift assays show that, despite its tight DNA binding, UL42 is capable of linear diffusion on DNA at a rate of between 17 and 47 bp/s. Our results thus suggest that, despite profound biochemical differences with the sliding clamps, UL42 can freely slide downstream with the catalytic subunit during DNA replication.