Arluison Veronique, Mutyam Shravan K, Mura Cameron, Marco Sergio, Sukhodolets Maxim V
Institut de Biologie Physico-Chimique, CNRS UPR 9073 conventionnee avec l'université Paris 7, 75005 Paris, France.
Protein Sci. 2007 Sep;16(9):1830-41. doi: 10.1110/ps.072883707. Epub 2007 Jul 27.
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.
Sm 样蛋白是普遍存在的环状寡聚体，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联，并且人们普遍认为它们的活性是通过核酸的被动结合来发挥的。我们早期对大肠杆菌 Sm 样蛋白 Hfq 的研究提供了首个证据，表明 Hfq 是一种 ATP 结合蛋白。通过结合生化和遗传技术，我们现已确定了 Hfq 中一个可能的 ATP 结合位点，并测试了 Hfq 的 ATP 结合亲和力和化学计量。RNA 足迹分析和结合分析结果表明，Hfq-RNA 复合物结合 ATP 会导致其显著不稳定。RNA 足迹分析表明，在 ATP 存在下，与 Hfq 结合的 RNA 片段会发生去保护，这表明它们被该蛋白释放。本文报道的结果拓宽了 Hfq 和其他 Sm 样蛋白在体内潜在作用的范围。
