Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
Bioessays. 2010 Aug;32(8):687-97. doi: 10.1002/bies.200900196.
In bacteria, PriA protein, a conserved DEXH-type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA-binding property allows it to recognize and stabilize stalled forks and the structures derived from them. Cells must cope with fork stalls caused by various replication stresses to complete replication of the entire genome. Failure of the stalled fork stabilization process and eventual restart could lead to various forms of genomic instability. The low viability of priA null cells indicates a frequent occurrence of fork stall during normal growth that needs to be properly processed. PriA specifically recognizes the 3'-terminus of the nascent leading strand or the invading strand in a displacement (D)-loop by the three-prime terminus binding pocket (TT-pocket) present in its unique DNA binding domain. Elucidation of the structural basis for recognition of arrested forks by PriA should provide useful insight into how stalled forks are recognized in eukaryotes.
在细菌中，PriA 蛋白是一种保守的 DEXH 型 DNA 解旋酶，在复制叉停滞时的复制起始中发挥核心作用。它独特的 DNA 结合特性使其能够识别和稳定停滞的复制叉及其衍生结构。细胞必须应对各种复制应激引起的复制叉停滞，以完成整个基因组的复制。停滞复制叉稳定过程的失败和最终的重新启动可能导致各种形式的基因组不稳定性。priA 缺失细胞的低存活率表明，在正常生长过程中经常会出现复制叉停滞，需要正确处理。PriA 蛋白通过其独特的 DNA 结合域中的三末端结合口袋（TT-口袋）特异性识别新生前导链的 3'末端或入侵链的置换（D）环。阐明 PriA 识别停滞复制叉的结构基础，应该为了解真核生物中如何识别停滞复制叉提供有用的线索。
