3qsu

<StructureSection load='3qsu' size='340' side='right' caption='[[3qsu]], [[Resolution|resolution]] 2.20&Aring;' scene=''>

<table><tr><td colspan='2'>[[3qsu]] is a 16 chain structure with sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus_subsp._aureus_ect-r_2 Staphylococcus aureus subsp. aureus ect-r 2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3QSU OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3QSU FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3gib|3gib]], [[1kq1|1kq1]], [[1kq2|1kq2]], [[3hsb|3hsb]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ECTR2_1161, hfq ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=889933 Staphylococcus aureus subsp. aureus ECT-R 2])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3qsu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qsu OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3qsu RCSB], [http://www.ebi.ac.uk/pdbsum/3qsu PDBsum]</span></td></tr>

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== Publication Abstract from PubMed ==

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)(3)A, 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 beta3 and beta4 eliminate the adenosine-specificity site (A-site) and create the L-site. Binding studies show that Sa Hfq binds (AU)(3)A approximately (AG)(3)A &gt;/= (AC)(3)A &gt; (AA)(3)A 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.

Structural mechanism of Staphylococcus aureus Hfq binding to an RNA A-tract.,Horstmann N, Orans J, Valentin-Hansen P, Shelburne SA 3rd, Brennan RG Nucleic Acids Res. 2012 Sep 10. PMID:22965117<ref>PMID:22965117</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Staphylococcus aureus subsp. aureus ect-r 2]]

[[Category: Brennan, R]]

[[Category: Horstmann, N]]

[[Category: Link, T M]]

[[Category: Translational regulator]]