Structural mechanism of Staphylococcus aureus Hfq binding to an RNA A-tract.
Structural mechanism of Staphylococcus aureus Hfq binding to an RNA A-tract.
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DOI：
10.1093/nar/gks809
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发表时间：
2012-11
影响因子：
14.9
通讯作者：
Brennan RG
中科院分区：
文献类型：
--
作者：
Horstmann N;Orans J;Valentin-Hansen P;Shelburne SA 3rd;Brennan RG
Hfq是一种转录后调节因子，通过结合富含AU的序列和A区以促进sRNA与靶mRNA的退火并影响RNA稳定性，在细菌基因表达中起关键作用。为了了解来自革兰氏阳性细菌金黄色葡萄球菌（Sa）的Hfq如何结合A束RNA，我们确定了Sa Hfq-腺嘌呤寡核糖核苷酸复合物的晶体结构。该结构揭示了远端面上的二分RNA结合基序，其由嘌呤核苷酸特异性位点（R-位点）和非识别性连接位点（L-位点）组成。（R-L）-结合基序也被枯草芽孢杆菌Hfq用于结合（AG）3A，其不同于大肠杆菌Hfq的（A-R-N）三联多聚（A）RNA-结合基序，其中Sa Hfq R-位点强烈偏好腺苷，更芳香并且允许腺嘌呤环更深地插入。在革兰氏阳性细菌Hfqs中保守的R位点腺嘌呤堆积残基Phe 30以及β3和β4构象的改变消除了腺苷特异性位点（A位点）并产生了L位点。结合研究表明，Sa Hfq与（Au）3A结合，其中（AG）3A ≥（AC）3A >（AA）3A，L位残基Lys 33起重要作用。（R-L）基序可能被来自大多数革兰氏阳性细菌的Hfqs用于结合交替的（A-N）n RNA。
Hfq is a post-transcriptional regulator that plays a key role in bacterial gene expression by binding AU-rich sequences and A-tracts to facilitate the annealing of sRNAs to target mRNAs and to affect RNA stability. To understand how Hfq from the Gram-positive bacterium Staphylococcus aureus (Sa) binds A-tract RNA, we determined the crystal structure of an Sa Hfq–adenine oligoribonucleotide complex. The structure reveals a bipartite RNA-binding motif on the distal face that is composed of a purine nucleotide-specificity site (R-site) and a non-discriminating linker site (L-site). The (R–L)-binding motif, which is also utilized by Bacillus subtilis Hfq to bind (AG)3A, differs from the (A–R–N) tripartite poly(A) RNA-binding motif of Escherichia coli Hfq whereby the Sa Hfq R-site strongly prefers adenosine, is more aromatic and permits deeper insertion of the adenine ring. R-site adenine-stacking residue Phe30, which is conserved among Gram-positive bacterial Hfqs, and an altered conformation about β3 and β4 eliminate the adenosine-specificity site (A-site) and create the L-site. Binding studies show that Sa Hfq binds (AU)3A ≈ (AG)3A ≥ (AC)3A > (AA)3A and L-site residue Lys33 plays a significant role. The (R–L) motif is likely utilized by Hfqs from most Gram-positive bacteria to bind alternating (A–N)n RNA.
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影响因子：
14.9
作者：
Lavery R;Moakher M;Maddocks JH;Petkeviciute D;Zakrzewska K
通讯作者：
Zakrzewska K
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
2.9
作者：
DEHASETH, PL;UHLENBECK, OC
通讯作者：
UHLENBECK, OC
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
6.7
作者：
Felden B;Vandenesch F;Bouloc P;Romby P
通讯作者：
Romby P