Sm-like protein Hfq: Location of the ATP-binding site and the effect of ATP on Hfq-RNA complexes
Sm-like protein Hfq: Location of the ATP-binding site and the effect of ATP on Hfq-RNA complexes
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DOI：
10.1110/ps.072883707
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发表时间：
2007-09-01
期刊：
影响因子：
8
通讯作者：
Sukhodolets, Maxim V.
中科院分区：
文献类型：
--
作者：
Arluison, Veronique;Mutyam, Shravan K.;Sukhodolets, Maxim V.
Sm样蛋白是一类广泛存在的环状寡聚体，具有多种核酸结合活性。它们在功能上与涉及RNA的各种细胞事件相关，并且通常认为它们的活性是通过核酸的被动结合来发挥的。我们早期对Sm样大肠杆菌蛋白Hfq的研究提供了第一个证据，表明Hfq是一种ATP结合蛋白。使用生物化学和遗传技术相结合，我们现在已经确定了一个合理的ATP结合位点在Hfq和测试Hfq的ATP结合亲和力和化学计量。RNA足迹和结合分析的结果表明，ATP结合的Hfq-RNA复合物的结果在其显着的不稳定。RNA足迹法表明在ATP存在下Hfq结合的RNA束的脱保护，表明它们被蛋白质释放。本文报道的结果拓宽了Hfq和其他Sm样蛋白的潜在体内作用的范围。
Sm-like proteins are ubiquitous ring-shaped oligomers that exhibit a variety of nucleic acid-binding activities. They have been linked functionally to various cellular events involving RNA, and it is generally believed that their activity is exerted via the passive binding of nucleic acids. Our earlier studies of the Sm-like Escherichia coli protein Hfq provided the first evidence indicating that Hfq is an ATP-binding protein. Using a combination of biochemical and genetic techniques, we have now determined a plausible ATP-binding site in Hfq and tested Hfq's ATP-binding affinity and stoichiometry. The results of RNA footprinting and binding analyses suggest that ATP binding by the Hfq-RNA complex results in its significant destabilization. RNA footprinting indicates deprotection of Hfq-bound RNA tracts in the presence of ATP, suggestive of their release by the protein. The results reported herein broaden the scope of potential in vivo roles for Hfq and other Sm-like proteins.