1riq
From Proteopedia
(New page: 200px<br /><applet load="1riq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1riq, resolution 2.14Å" /> '''The crystal structur...) |
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| - | [[Image:1riq.gif|left|200px]]<br /><applet load="1riq" size=" | + | [[Image:1riq.gif|left|200px]]<br /><applet load="1riq" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1riq, resolution 2.14Å" /> | caption="1riq, resolution 2.14Å" /> | ||
'''The crystal structure of the catalytic fragment of the alanyl-tRNA synthetase'''<br /> | '''The crystal structure of the catalytic fragment of the alanyl-tRNA synthetase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Early work on aminoacylation of alanine-specific tRNA (tRNA(Ala)) by | + | Early work on aminoacylation of alanine-specific tRNA (tRNA(Ala)) by alanyl-tRNA synthetase (AlaRS) gave rise to the concept of an early "second genetic code" imbedded in the acceptor stems of tRNAs. A single conserved and position-specific G:U base pair in the tRNA acceptor stem is the key identity determinant. Further understanding has been limited due to lack of a crystal structure of the enzyme. We determined a 2.14 A crystal structure of the 453 amino acid catalytic fragment of Aquifex aeolicus AlaRS. It contains the catalytic domain characteristic of class II synthetases, a helical domain with a hairpin motif critical for acceptor-stem recognition, and a C-terminal domain of a mixed alpha/beta fold. Docking of tRNA(Ala) on AlaRS shows critical contacts with the three domains, consistent with previous mutagenesis and functional data. It also suggests conformational flexibility within the C domain, which might allow for the positional variation of the key G:U base pair seen in some tRNA(Ala)s. |
==About this Structure== | ==About this Structure== | ||
| - | 1RIQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquifex_aeolicus Aquifex aeolicus]. Active as [http://en.wikipedia.org/wiki/Alanine--tRNA_ligase Alanine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.7 6.1.1.7] Full crystallographic information is available from [http:// | + | 1RIQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aquifex_aeolicus Aquifex aeolicus]. Active as [http://en.wikipedia.org/wiki/Alanine--tRNA_ligase Alanine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.7 6.1.1.7] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RIQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Aquifex aeolicus]] | [[Category: Aquifex aeolicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Lovato, M | + | [[Category: Lovato, M A.]] |
| - | [[Category: McRee, D | + | [[Category: McRee, D E.]] |
| - | [[Category: Otero, F | + | [[Category: Otero, F J.]] |
| - | [[Category: Pouplana, L | + | [[Category: Pouplana, L Ribas de.]] |
[[Category: Schimmel, P.]] | [[Category: Schimmel, P.]] | ||
| - | [[Category: Skene, R | + | [[Category: Skene, R J.]] |
| - | [[Category: Swairjo, M | + | [[Category: Swairjo, M A.]] |
| - | [[Category: Yang, X | + | [[Category: Yang, X L.]] |
[[Category: beta sheet and flanking helices]] | [[Category: beta sheet and flanking helices]] | ||
[[Category: class ii aminoacyl-trna synthetase]] | [[Category: class ii aminoacyl-trna synthetase]] | ||
[[Category: helix-loop-helix motif]] | [[Category: helix-loop-helix motif]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:51:18 2008'' |
Revision as of 12:51, 21 February 2008
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The crystal structure of the catalytic fragment of the alanyl-tRNA synthetase
Overview
Early work on aminoacylation of alanine-specific tRNA (tRNA(Ala)) by alanyl-tRNA synthetase (AlaRS) gave rise to the concept of an early "second genetic code" imbedded in the acceptor stems of tRNAs. A single conserved and position-specific G:U base pair in the tRNA acceptor stem is the key identity determinant. Further understanding has been limited due to lack of a crystal structure of the enzyme. We determined a 2.14 A crystal structure of the 453 amino acid catalytic fragment of Aquifex aeolicus AlaRS. It contains the catalytic domain characteristic of class II synthetases, a helical domain with a hairpin motif critical for acceptor-stem recognition, and a C-terminal domain of a mixed alpha/beta fold. Docking of tRNA(Ala) on AlaRS shows critical contacts with the three domains, consistent with previous mutagenesis and functional data. It also suggests conformational flexibility within the C domain, which might allow for the positional variation of the key G:U base pair seen in some tRNA(Ala)s.
About this Structure
1RIQ is a Single protein structure of sequence from Aquifex aeolicus. Active as Alanine--tRNA ligase, with EC number 6.1.1.7 Full crystallographic information is available from OCA.
Reference
Alanyl-tRNA synthetase crystal structure and design for acceptor-stem recognition., Swairjo MA, Otero FJ, Yang XL, Lovato MA, Skene RJ, McRee DE, Ribas de Pouplana L, Schimmel P, Mol Cell. 2004 Mar 26;13(6):829-41. PMID:15053876
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