Roles of functional loops and the C-terminal segment of a single-stranded DNA binding protein elucidated by x-ray structure analysis
Roles of functional loops and the C-terminal segment of a single-stranded DNA binding protein elucidated by x-ray structure analysis
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DOI：
10.1093/oxfordjournals.jbchem.a022611
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发表时间：
2000-02-01
影响因子：
2.7
通讯作者：
Yasuoka, N
中科院分区：
文献类型：
--
作者：
Matsumoto, T;Morimoto, Y;Yasuoka, N
大肠杆菌单链DNA结合蛋白(EcoSSB)在DNA复制、重组和修复中起着核心作用：EcoSSB的三级结构是在2.2埃分辨率下确定的。这比之前报道的分辨率要高得多。晶体是从均一的完整蛋白质中生长出来的，但晶体中的EcoSSB四聚体含有截短的亚基，缺少部分C-末端，所确定的结构包括具有重要生物学意义的柔性环和C-末端区域，并揭示了凹陷的存在。这些凹陷包括对单链DNA结合重要的残基。单链DNA可以安装在凹面上，并通过与形成柔性盖子的环相互作用来进一步稳定。它似乎可能在单链DNA的结合中发挥核心作用。
The single-stranded DNA (ssDNA) binding protein from Escherichia coli (EcoSSB) plays a central role in DNA replication, recombination, and repair: The tertiary structure of EcoSSB was determined at 2.2 Angstrom resolution. This is rather higher resolution than previously reported. Crystals were grown from the homogeneous intact protein but the EcoSSB tetramer in the crystals contains truncated subunits lacking a part of the C-terminal, The structure determined includes biologically important flexible loops and C-terminal regions, and revealed the existence of concavities. These concavities include the residues important for ssDNA binding. An ssDNA can be fitted on the concavities and further stabilized through interactions with the loops forming flexible lids. It seems likely to play a central role in the binding of ssDNA.