Identification and properties of the crenarchaeal single-stranded DNA binding protein from Sulfolobus solfataricus
Identification and properties of the crenarchaeal single-stranded DNA binding protein from Sulfolobus solfataricus
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DOI：
10.1093/nar/29.4.914
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发表时间：
2001-02-15
影响因子：
14.9
通讯作者：
White, MF
中科院分区：
文献类型：
--
作者：
Wadsworth, RIM;White, MF
单链DNA结合蛋白(SSB)在细胞和病毒产生单链DNA的过程中起着核心作用，包括DNA复制、同源重组和DNA修复途径。SSB使用四个‘OB-折叠’(寡核苷酸/低聚糖结合折叠)结构域结合DNA，这些结构域可以组织成各种整体的四级结构。因此，真细菌SSB是同源四聚体，而真核RPA蛋白是-异三聚体，真毛虫蛋白的亚基组成有很大的差异。我们证明了古生菌SSB蛋白是一种丰富的蛋白质，具有独特的结构组织，以单体形式存在于溶液中，并以DNA结合的方式多聚体存在。该蛋白以分布的方式与单链DMA结合，结合部位大小类似于每个单体5个核苷酸，Sulfolobus SSB缺乏在真核和真毛虫蛋白中发现的锌指基序，而是具有灵活的C-末端尾巴，对胰酶消化敏感，这是DNA结合所不需要的。与大肠杆菌SSB相比，尾巴可能在DNA复制和修复过程中发挥蛋白质-蛋白质相互作用的作用。
Single-stranded DNA binding proteins (SSBs) play central roles in cellular and viral processes involving the:generation of single-stranded DNA, These include DNA replication, homologous recombination and DNA repair pathways. SSBs bind DNA using four 'OB-fold' (oligonucleotide/oligosaccharide binding fold) domains that can be organised in a variety of overall quaternary structures. Thus eubacterial SSBs are homotetrameric whilst the eucaryal RPA protein is a-heterotrimer and euryarchaeal proteins vary significantly in their subunit compositions, We demonstrate that the crenarchaeal SSB protein is an abundant protein with a unique structural organisation, existing as a monomer in solution and multimerising on DNA binding. The protein binds single-stranded DMA distributively with a binding site size of similar to5 nt per monomer, Sulfolobus SSB lacks the zinc finger motif found in the eucaryal and euryarchaeal proteins, possessing instead a flexible C-terminal tail, sensitive to trypsin digestion, that is not required for DNA binding, In comparison with Escherichia coli SSB, the tail may play a role in protein-protein interactions during DNA replication and repair.