Crystal structure and RNA-binding properties of an Hfq homolog from the deep-branching Aquificae: conservation of the lateral RNA-binding mode
Crystal structure and RNA-binding properties of an Hfq homolog from the deep-branching Aquificae: conservation of the lateral RNA-binding mode
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深分支 Aquiificae 的 Hfq 同源物的晶体结构和 RNA 结合特性：横向 RNA 结合模式的保守
DOI：
10.1107/s2059798317000031
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Mura, Cameron
中科院分区：
文献类型：
--
作者：
Stanek, Kimberly A.;Patterson-West, Jennifer;Randolph, Peter S.;Mura, Cameron
宿主因子Hfq作为Sm家族的细菌分支，是一种RNA结合蛋白，参与mRNA表达和周转的转录后调节。Hfq通过结合小调节RNA（sRNA）和它们相应的mRNA靶标并使它们紧密接近来促进两者之间的配对。Hfq同源物自组装成具有至少两个结合RNA的不同表面的同源六聚体环。最近，另一个结合位点，被称为“侧缘”，已经涉及sRNA·mRNA退火;该位点的RNA结合特性似乎相当微妙，其进化保守程度尚不清楚。一个Hfq同源物已被确定在深分支的嗜热Aquifex aeolicus（Aae），但很少有人知道Hfq的结构和功能的基础细菌谱系，如Aquificae。因此，Aae Hfq被克隆、过表达、纯化、结晶和生化表征。在空间群P1和P6中确定了Aae Hfq的结构，两者都达到1.5 μ m分辨率，并发现了对尿苷和腺苷丰富的RNA的纳摩尔级结合亲和力。 与U6 RNA的共结晶揭示了Aae Hfq六聚体的外缘具有对尿嘧啶具有选择性的明确定义的结合口袋。这种Aae Hfq结构，结合同源物的生物化学和生物物理学特征，揭示了侧向RNA结合模式的深层进化保守性，并为进一步研究Hfq相关的RNA生物学在古细菌门奠定了基础。
The host factor Hfq, as the bacterial branch of the Sm family, is an RNA-binding protein involved in the post-transcriptional regulation of mRNA expression and turnover. Hfq facilitates pairing between small regulatory RNAs (sRNAs) and their corresponding mRNA targets by binding both RNAs and bringing them into close proximity. Hfq homologs self-assemble into homo-hexameric rings with at least two distinct surfaces that bind RNA. Recently, another binding site, dubbed the `lateral rim', has been implicated in sRNA·mRNA annealing; the RNA-binding properties of this site appear to be rather subtle, and its degree of evolutionary conservation is unknown. An Hfq homolog has been identified in the phylogenetically deep-branching thermophile Aquifex aeolicus (Aae), but little is known about the structure and function of Hfq from basal bacterial lineages such as the Aquificae. Therefore, Aae Hfq was cloned, overexpressed, purified, crystallized and biochemically characterized. Structures of Aae Hfq were determined in space groups P1 and P6, both to 1.5 Å resolution, and nanomolar-scale binding affinities for uridine- and adenosine-rich RNAs were discovered. Co-crystallization with U6 RNA reveals that the outer rim of the Aae Hfq hexamer features a well defined binding pocket that is selective for uracil. This Aae Hfq structure, combined with biochemical and biophysical characterization of the homolog, reveals deep evolutionary conservation of the lateral RNA-binding mode, and lays a foundation for further studies of Hfq-associated RNA biology in ancient bacterial phyla.
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影响因子：
14.9
作者：
Wang W;Wang L;Wu J;Gong Q;Shi Y
通讯作者：
Shi Y
影响因子：
4.3
作者：
Mura, Cameron;McCrimmon, Colin M.;Sawaya, Michael R.
通讯作者：
Sawaya, Michael R.
R.G.Duggleby：“酶学方法”
DOI：
--
发表时间：
--
期刊：
影响因子：
--
作者：
通讯作者：
--
DOI：
10.1073/pnas.92.19.8793
发表时间：
1995-09-12
影响因子：
11.1
作者：
WILSON, KS;VONHIPPEL, PH
通讯作者：
VONHIPPEL, PH
影响因子：
2.8
作者：
Murina, V. N.;Melnik, B. S.;Nikulin, A. D.
通讯作者：
Nikulin, A. D.