405d
From Proteopedia
(New page: 200px<br /><applet load="405d" size="350" color="white" frame="true" align="right" spinBox="true" caption="405d, resolution 2.50Å" /> '''STRUCTURE OF A 16-ME...) |
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==Overview== | ==Overview== | ||
| - | The crystal structure of a 16-mer, the longest known RNA duplex, has been | + | The crystal structure of a 16-mer, the longest known RNA duplex, has been determined at 2.5 A resolution. The hexadecamer r(GCAGACUUAAAUCUGC) contains isolated C.A/A.C mismatches with two hydrogen bonds. The two hydrogen bonds in the mismatches suggests that N1 of A is protonated even though the crystallization was done at neutral pH. Therefore, the C.A mismatch is a C.A+ wobble similar to the G.U wobble. The two C.A+ pairs are isolated by four Watson-Crick pairs and flanked by five Watson-Crick base-pairs on either sides. Kinks/bends of 20 degrees are observed at the wobble sites. The Watson-Crick base-pair A5.U26 on the 5'-side of the first C6.A27(+) wobble has a twist angle of 27 degrees compared to the 3'-side U7.A28 pair of 36 degrees. The twist angles are reversed (37 degrees and 26 degrees) in the second A11(+).C22 wobble because of the approximate dyad in the molecule, the flanking base-pair sequences are A.U pairs. The wobbles expand the major groove to 7.1 A/7.3 A. The duplexes form helical columns and are tightly packed around the 31-screw axis. The minor grooves of adjacent columns in juxtaposition interact through the O2' atoms and the anionic phosphate oxygen atoms.Copyright 1998 Academic Press. |
==About this Structure== | ==About this Structure== | ||
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Structure of a 16-mer RNA duplex r(GCAGACUUAAAUCUGC)2 with wobble C.A+ mismatches., Pan B, Mitra SN, Sundaralingam M, J Mol Biol. 1998 Nov 13;283(5):977-84. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9799637 9799637] | Structure of a 16-mer RNA duplex r(GCAGACUUAAAUCUGC)2 with wobble C.A+ mismatches., Pan B, Mitra SN, Sundaralingam M, J Mol Biol. 1998 Nov 13;283(5):977-84. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9799637 9799637] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Mitra, S | + | [[Category: Mitra, S N.]] |
| - | [[Category: Pan, M | + | [[Category: Pan, M Sundaralingam B.]] |
[[Category: a-rna double helix]] | [[Category: a-rna double helix]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:11:55 2008'' |
Revision as of 17:11, 21 February 2008
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STRUCTURE OF A 16-MER RNA DUPLEX R(GCAGACUUAAAUCUGC)2 WITH WOBBLE LIKE A.C MISMATCHES
Overview
The crystal structure of a 16-mer, the longest known RNA duplex, has been determined at 2.5 A resolution. The hexadecamer r(GCAGACUUAAAUCUGC) contains isolated C.A/A.C mismatches with two hydrogen bonds. The two hydrogen bonds in the mismatches suggests that N1 of A is protonated even though the crystallization was done at neutral pH. Therefore, the C.A mismatch is a C.A+ wobble similar to the G.U wobble. The two C.A+ pairs are isolated by four Watson-Crick pairs and flanked by five Watson-Crick base-pairs on either sides. Kinks/bends of 20 degrees are observed at the wobble sites. The Watson-Crick base-pair A5.U26 on the 5'-side of the first C6.A27(+) wobble has a twist angle of 27 degrees compared to the 3'-side U7.A28 pair of 36 degrees. The twist angles are reversed (37 degrees and 26 degrees) in the second A11(+).C22 wobble because of the approximate dyad in the molecule, the flanking base-pair sequences are A.U pairs. The wobbles expand the major groove to 7.1 A/7.3 A. The duplexes form helical columns and are tightly packed around the 31-screw axis. The minor grooves of adjacent columns in juxtaposition interact through the O2' atoms and the anionic phosphate oxygen atoms.Copyright 1998 Academic Press.
About this Structure
405D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Structure of a 16-mer RNA duplex r(GCAGACUUAAAUCUGC)2 with wobble C.A+ mismatches., Pan B, Mitra SN, Sundaralingam M, J Mol Biol. 1998 Nov 13;283(5):977-84. PMID:9799637
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