4oqu: Difference between revisions
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''' | ==Structure of the SAM-I/IV riboswitch (env87(deltaU92))== | ||
<StructureSection load='4oqu' size='340' side='right' caption='[[4oqu]], [[Resolution|resolution]] 3.20Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4oqu]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4OQU OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4OQU FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SAM:S-ADENOSYLMETHIONINE'>SAM</scene><br> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4oqu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4oqu OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4oqu RCSB], [http://www.ebi.ac.uk/pdbsum/4oqu PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
In bacteria, sulfur metabolism is regulated in part by seven known families of riboswitches that bind S-adenosyl-l-methionine (SAM). Direct binding of SAM to these mRNA regulatory elements governs a downstream secondary structural switch that communicates with the transcriptional and/or translational expression machinery. The most widely distributed SAM-binding riboswitches belong to the SAM clan, comprising three families that share a common SAM-binding core but differ radically in their peripheral architecture. Although the structure of the SAM-I member of this clan has been extensively studied, how the alternative peripheral architecture of the other families supports the common SAM-binding core remains unknown. We have therefore solved the X-ray structure of a member of the SAM-I/IV family containing the alternative "PK-2" subdomain shared with the SAM-IV family. This structure reveals that this subdomain forms extensive interactions with the helix housing the SAM-binding pocket, including a highly unusual mode of helix packing in which two helices pack in a perpendicular fashion. Biochemical and genetic analysis of this RNA reveals that SAM binding induces many of these interactions, including stabilization of a pseudoknot that is part of the regulatory switch. Despite strong structural similarity between the cores of SAM-I and SAM-I/IV members, a phylogenetic analysis of sequences does not indicate that they derive from a common ancestor. | |||
Structural basis for diversity in the SAM clan of riboswitches.,Trausch JJ, Xu Z, Edwards AL, Reyes FE, Ross PE, Knight R, Batey RT Proc Natl Acad Sci U S A. 2014 May 6;111(18):6624-9. doi:, 10.1073/pnas.1312918111. Epub 2014 Apr 21. PMID:24753586<ref>PMID:24753586</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Batey, R T.]] | |||
[[Category: Edwards, A L.]] | |||
[[Category: Reyes, F E.]] | |||
[[Category: Trausch, J J.]] | |||
[[Category: Aptamer]] | |||
[[Category: Pseudoknot]] | |||
[[Category: Regulation]] | |||
[[Category: Riboswitch]] | |||
[[Category: Rna]] | |||
[[Category: S-adenosylmethionine]] | |||
Revision as of 08:06, 4 June 2014
Structure of the SAM-I/IV riboswitch (env87(deltaU92))Structure of the SAM-I/IV riboswitch (env87(deltaU92))
Structural highlights
Publication Abstract from PubMedIn bacteria, sulfur metabolism is regulated in part by seven known families of riboswitches that bind S-adenosyl-l-methionine (SAM). Direct binding of SAM to these mRNA regulatory elements governs a downstream secondary structural switch that communicates with the transcriptional and/or translational expression machinery. The most widely distributed SAM-binding riboswitches belong to the SAM clan, comprising three families that share a common SAM-binding core but differ radically in their peripheral architecture. Although the structure of the SAM-I member of this clan has been extensively studied, how the alternative peripheral architecture of the other families supports the common SAM-binding core remains unknown. We have therefore solved the X-ray structure of a member of the SAM-I/IV family containing the alternative "PK-2" subdomain shared with the SAM-IV family. This structure reveals that this subdomain forms extensive interactions with the helix housing the SAM-binding pocket, including a highly unusual mode of helix packing in which two helices pack in a perpendicular fashion. Biochemical and genetic analysis of this RNA reveals that SAM binding induces many of these interactions, including stabilization of a pseudoknot that is part of the regulatory switch. Despite strong structural similarity between the cores of SAM-I and SAM-I/IV members, a phylogenetic analysis of sequences does not indicate that they derive from a common ancestor. Structural basis for diversity in the SAM clan of riboswitches.,Trausch JJ, Xu Z, Edwards AL, Reyes FE, Ross PE, Knight R, Batey RT Proc Natl Acad Sci U S A. 2014 May 6;111(18):6624-9. doi:, 10.1073/pnas.1312918111. Epub 2014 Apr 21. PMID:24753586[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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