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1i3x
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| - | [[Image:1i3x.gif|left|200px]] | ||
| - | < | + | ==SOLUTION STRUCTURE OF THE A LOOP OF 23S RIBOSOMAL RNA== |
| - | + | <StructureSection load='1i3x' size='340' side='right'caption='[[1i3x]]' scene=''> | |
| - | + | == Structural highlights == | |
| - | + | <table><tr><td colspan='2'>[[1i3x]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I3X OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1I3X FirstGlance]. <br> | |
| - | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> | |
| - | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1i3x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i3x OCA], [https://pdbe.org/1i3x PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1i3x RCSB], [https://www.ebi.ac.uk/pdbsum/1i3x PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1i3x ProSAT]</span></td></tr> | |
| - | + | </table> | |
| - | + | <div style="background-color:#fffaf0;"> | |
| - | ''' | + | == Publication Abstract from PubMed == |
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The A loop is an essential RNA component of the ribosome peptidyltransferase center that directly interacts with aminoacyl (A)-site tRNA. The A loop is highly conserved and contains a ubiquitous 2'-O-methyl ribose modification at position U2552. Here, we present the solution structure of a modified and unmodified A-loop RNA to define both the A-loop fold and the structural impact of the U2552 modification. Solution data reveal that the A-loop RNA has a compact structure that includes a noncanonical base pair between C2556 and U2552. NMR evidence is presented that the N3 position of C2556 has a shifted pKa and that protonation at C2556-N3 changes the C-U pair geometry. Our data indicate that U2552 methylation modifies the A-loop fold, in particular the dynamics and position of residues C2556 and U2555. We compare our structural data with the structure of the A loop observed in a recent 50S crystal structure [Ban, N., Nissen, P., Hansen, J., Moore, P. B. & Steitz, T. A. (2000) Science 289, 905--920; Nissen, P., Hansen, J., Ban, N., Moore, P. B. & Steitz, T. A. (2000) Science 289, 920--930]. The solution and crystal structures of the A loop are dramatically different, suggesting that a structural rearrangement of the A loop must occur on docking into the peptidyltransferase center. Possible roles of this docking event, the shifted pKa of C2556 and the U2552 2'-O-methylation in the mechanism of translation, are discussed. | The A loop is an essential RNA component of the ribosome peptidyltransferase center that directly interacts with aminoacyl (A)-site tRNA. The A loop is highly conserved and contains a ubiquitous 2'-O-methyl ribose modification at position U2552. Here, we present the solution structure of a modified and unmodified A-loop RNA to define both the A-loop fold and the structural impact of the U2552 modification. Solution data reveal that the A-loop RNA has a compact structure that includes a noncanonical base pair between C2556 and U2552. NMR evidence is presented that the N3 position of C2556 has a shifted pKa and that protonation at C2556-N3 changes the C-U pair geometry. Our data indicate that U2552 methylation modifies the A-loop fold, in particular the dynamics and position of residues C2556 and U2555. We compare our structural data with the structure of the A loop observed in a recent 50S crystal structure [Ban, N., Nissen, P., Hansen, J., Moore, P. B. & Steitz, T. A. (2000) Science 289, 905--920; Nissen, P., Hansen, J., Ban, N., Moore, P. B. & Steitz, T. A. (2000) Science 289, 920--930]. The solution and crystal structures of the A loop are dramatically different, suggesting that a structural rearrangement of the A loop must occur on docking into the peptidyltransferase center. Possible roles of this docking event, the shifted pKa of C2556 and the U2552 2'-O-methylation in the mechanism of translation, are discussed. | ||
| - | + | Solution structure of the A loop of 23S ribosomal RNA.,Blanchard SC, Puglisi JD Proc Natl Acad Sci U S A. 2001 Mar 27;98(7):3720-5. Epub 2001 Mar 20. PMID:11259644<ref>PMID:11259644</ref> | |
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| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | <div class="pdbe-citations 1i3x" style="background-color:#fffaf0;"></div> | |
| - | + | == References == | |
| - | [[Category: | + | <references/> |
| - | [[Category: | + | __TOC__ |
| - | [[Category: | + | </StructureSection> |
| - | + | [[Category: Large Structures]] | |
| + | [[Category: Blanchard SC]] | ||
| + | [[Category: Puglisi JD]] | ||
Current revision
SOLUTION STRUCTURE OF THE A LOOP OF 23S RIBOSOMAL RNA
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