1bs2
From Proteopedia
(New page: 200px<br /><applet load="1bs2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bs2, resolution 2.75Å" /> '''YEAST ARGINYL-TRNA S...) |
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- | [[Image:1bs2.gif|left|200px]]<br /><applet load="1bs2" size=" | + | [[Image:1bs2.gif|left|200px]]<br /><applet load="1bs2" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bs2, resolution 2.75Å" /> | caption="1bs2, resolution 2.75Å" /> | ||
'''YEAST ARGINYL-TRNA SYNTHETASE'''<br /> | '''YEAST ARGINYL-TRNA SYNTHETASE'''<br /> | ||
==Overview== | ==Overview== | ||
- | The crystal structure of arginyl-tRNA synthetase (ArgRS) from | + | The crystal structure of arginyl-tRNA synthetase (ArgRS) from Saccharomyces cerevisiae, a class I aminoacyl-tRNA synthetase (aaRS), with L-arginine bound to the active site has been solved at 2.75 A resolution and refined to a crystallographic R-factor of 19.7%. ArgRS is composed predominantly of alpha-helices and can be divided into five domains, including the class I-specific active site. The N-terminal domain shows striking similarity to some completely unrelated proteins and defines a module which should participate in specific tRNA recognition. The C-terminal domain, which is the putative anticodon-binding module, displays an all-alpha-helix fold highly similar to that of Escherichia coli methionyl-tRNA synthetase. While ArgRS requires tRNAArg for the first step of the aminoacylation reaction, the results show that its presence is not a prerequisite for L-arginine binding. All H-bond-forming capability of L-arginine is used by the protein for the specific recognition. The guanidinium group forms two salt bridge interactions with two acidic residues, and one H-bond with a tyrosine residue; these three residues are strictly conserved in all ArgRS sequences. This tyrosine is also conserved in other class I aaRS active sites but plays several functional roles. The ArgRS structure allows the definition of a new framework for sequence alignments and subclass definition in class I aaRSs. |
==About this Structure== | ==About this Structure== | ||
- | 1BS2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with ARG as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Arginine--tRNA_ligase Arginine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.19 6.1.1.19] Full crystallographic information is available from [http:// | + | 1BS2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=ARG:'>ARG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Arginine--tRNA_ligase Arginine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.19 6.1.1.19] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BS2 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: protein biosynthesis]] | [[Category: protein biosynthesis]] | ||
- | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:58:28 2008'' |
Revision as of 09:58, 21 February 2008
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YEAST ARGINYL-TRNA SYNTHETASE
Overview
The crystal structure of arginyl-tRNA synthetase (ArgRS) from Saccharomyces cerevisiae, a class I aminoacyl-tRNA synthetase (aaRS), with L-arginine bound to the active site has been solved at 2.75 A resolution and refined to a crystallographic R-factor of 19.7%. ArgRS is composed predominantly of alpha-helices and can be divided into five domains, including the class I-specific active site. The N-terminal domain shows striking similarity to some completely unrelated proteins and defines a module which should participate in specific tRNA recognition. The C-terminal domain, which is the putative anticodon-binding module, displays an all-alpha-helix fold highly similar to that of Escherichia coli methionyl-tRNA synthetase. While ArgRS requires tRNAArg for the first step of the aminoacylation reaction, the results show that its presence is not a prerequisite for L-arginine binding. All H-bond-forming capability of L-arginine is used by the protein for the specific recognition. The guanidinium group forms two salt bridge interactions with two acidic residues, and one H-bond with a tyrosine residue; these three residues are strictly conserved in all ArgRS sequences. This tyrosine is also conserved in other class I aaRS active sites but plays several functional roles. The ArgRS structure allows the definition of a new framework for sequence alignments and subclass definition in class I aaRSs.
About this Structure
1BS2 is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Active as Arginine--tRNA ligase, with EC number 6.1.1.19 Full crystallographic information is available from OCA.
Reference
L-arginine recognition by yeast arginyl-tRNA synthetase., Cavarelli J, Delagoutte B, Eriani G, Gangloff J, Moras D, EMBO J. 1998 Sep 15;17(18):5438-48. PMID:9736621
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