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1i3y
From Proteopedia
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'''SOLUTION STRUCTURE OF THE A LOOP OF 23S RIBOSOMAL RNA.''' | '''SOLUTION STRUCTURE OF THE A LOOP OF 23S RIBOSOMAL RNA.''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | + | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I3Y OCA]. | |
==Reference== | ==Reference== | ||
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:[http://www.ncbi.nlm.nih.gov/pubmed/11259644 11259644] | 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:[http://www.ncbi.nlm.nih.gov/pubmed/11259644 11259644] | ||
| - | [[Category: Protein complex]] | ||
[[Category: Blanchard, S C.]] | [[Category: Blanchard, S C.]] | ||
[[Category: Puglisi, J D.]] | [[Category: Puglisi, J D.]] | ||
[[Category: 23s rrna]] | [[Category: 23s rrna]] | ||
| - | [[Category: | + | [[Category: A loop]] |
| - | [[Category: | + | [[Category: A site]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 19:32:42 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 16:32, 2 May 2008
SOLUTION STRUCTURE OF THE A LOOP OF 23S RIBOSOMAL RNA.
Overview
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.
About this Structure
Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Fri May 2 19:32:42 2008
