2ylc

Structure of Salmonella typhimurium Hfq in complex with U6 RNA

spinqualitylabelsall models 2ylc, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ylc is a 1 chain structure with sequence from Salty. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SCN Related: 2ylb Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [HFQ_SALTY] RNA chaperone that binds small regulatory RNA (sRNAs) and mRNAs to facilitate mRNA translational regulation in response to envelope stress, environmental stress and changes in metabolite concentrations. Also binds with high specificity to tRNAs (By similarity). Plays a central regulatory role in the microbial response to space flight conditions. Is essential for virulence and is required for efficient invasion of non-phagocytic cells.[HAMAP-Rule:MF_00436] Publication Abstract from PubMed The homohexameric (L)Sm protein Hfq is a central mediator of small RNA-based gene regulation in bacteria. Hfq recognizes small regulatory RNAs (sRNAs) specifically, despite their structural diversity. This specificity could not be explained by previously described RNA-binding modes of Hfq. Here we present a distinct and preferred mode of Hfq-RNA interaction that involves the direct recognition of a uridine-rich RNA 3' end. This feature is common in bacterial RNA transcripts as a consequence of Rho-independent transcription termination and hence likely contributes significantly to the general recognition of sRNAs by Hfq. Isothermal titration calorimetry shows nanomolar affinity between Salmonella typhimurium Hfq and a hexauridine substrate. We determined a crystal structure of the complex that reveals a constricted RNA backbone conformation in the proximal RNA-binding site of Hfq, allowing for a direct protein contact of the 3' hydroxyl group. A free 3' hydroxyl group is crucial for the high-affinity interaction with Hfq also in the context of a full-length sRNA substrate, RybB. The capacity of Hfq to occupy and sequester the RNA 3' end has important implications for the mechanisms by which Hfq is thought to affect sRNA stability, turnover, and regulation. Structural basis for RNA 3'-end recognition by Hfq.,Sauer E, Weichenrieder O Proc Natl Acad Sci U S A. 2011 Aug 9;108(32):13065-70. Epub 2011 Jul 7. PMID:21737752 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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