1vbn
From Proteopedia
(New page: 200px<br /><applet load="1vbn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vbn, resolution 2.70Å" /> '''Escherichia coli tyr...) |
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| - | [[Image:1vbn.gif|left|200px]]<br /><applet load="1vbn" size=" | + | [[Image:1vbn.gif|left|200px]]<br /><applet load="1vbn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1vbn, resolution 2.70Å" /> | caption="1vbn, resolution 2.70Å" /> | ||
'''Escherichia coli tyrosyl-tRNA synthetase mutant complexed with Tyr-AMS'''<br /> | '''Escherichia coli tyrosyl-tRNA synthetase mutant complexed with Tyr-AMS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The genetic code in a eukaryotic system has been expanded by the | + | The genetic code in a eukaryotic system has been expanded by the engineering of Escherichia coli tyrosyl-tRNA synthetase (TyrRS) with the Y37V and Q195C mutations (37V195C), which specifically recognize 3-iodo-L-tyrosine rather than L-tyrosine. In the present study, we determined the 3-iodo-L-tyrosine- and L-tyrosine-bound structures of the 37V195C mutant of the E. coli TyrRS catalytic domain at 2.0-A resolution. The gamma-methyl group of Val-37 and the sulfur atom of Cys-195 make van der Waals contacts with the iodine atom of 3-iodo-L-tyrosine. The Val-37 and Cys-195 side chains are rigidly fixed by the neighboring residues forming the hydrophobic core of the TyrRS. The major roles of the two mutations are different for the 3-iodo-L-tyrosine-selective recognition in the first step of the aminoacylation reaction (the amino acid activation step): the Y37V mutation eliminates the fatal steric repulsion with the iodine atom, and the Q195C mutation reduces the L-tyrosine misrecognition. The structure of the 37V195C mutant TyrRS complexed with an L-tyrosyladenylate analogue was also solved, indicating that the 3-iodo-L-tyrosine and L-tyrosine side chains are similarly discriminated in the second step (the aminoacyl transfer step). These results demonstrate that the amino acid-binding pocket on the 37V195C mutant is optimized for specific 3-iodo-L-tyrosine recognition. |
==About this Structure== | ==About this Structure== | ||
| - | 1VBN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with YSA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Tyrosine--tRNA_ligase Tyrosine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.1 6.1.1.1] Full crystallographic information is available from [http:// | + | 1VBN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=YSA:'>YSA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Tyrosine--tRNA_ligase Tyrosine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.1 6.1.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VBN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Kobayashi, T.]] | [[Category: Kobayashi, T.]] | ||
[[Category: Nishimura, S.]] | [[Category: Nishimura, S.]] | ||
| - | [[Category: RSGI, RIKEN | + | [[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]] |
[[Category: Sakamoto, K.]] | [[Category: Sakamoto, K.]] | ||
[[Category: Sekine, R.]] | [[Category: Sekine, R.]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:33:43 2008'' |
Revision as of 13:33, 21 February 2008
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Escherichia coli tyrosyl-tRNA synthetase mutant complexed with Tyr-AMS
Overview
The genetic code in a eukaryotic system has been expanded by the engineering of Escherichia coli tyrosyl-tRNA synthetase (TyrRS) with the Y37V and Q195C mutations (37V195C), which specifically recognize 3-iodo-L-tyrosine rather than L-tyrosine. In the present study, we determined the 3-iodo-L-tyrosine- and L-tyrosine-bound structures of the 37V195C mutant of the E. coli TyrRS catalytic domain at 2.0-A resolution. The gamma-methyl group of Val-37 and the sulfur atom of Cys-195 make van der Waals contacts with the iodine atom of 3-iodo-L-tyrosine. The Val-37 and Cys-195 side chains are rigidly fixed by the neighboring residues forming the hydrophobic core of the TyrRS. The major roles of the two mutations are different for the 3-iodo-L-tyrosine-selective recognition in the first step of the aminoacylation reaction (the amino acid activation step): the Y37V mutation eliminates the fatal steric repulsion with the iodine atom, and the Q195C mutation reduces the L-tyrosine misrecognition. The structure of the 37V195C mutant TyrRS complexed with an L-tyrosyladenylate analogue was also solved, indicating that the 3-iodo-L-tyrosine and L-tyrosine side chains are similarly discriminated in the second step (the aminoacyl transfer step). These results demonstrate that the amino acid-binding pocket on the 37V195C mutant is optimized for specific 3-iodo-L-tyrosine recognition.
About this Structure
1VBN is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Tyrosine--tRNA ligase, with EC number 6.1.1.1 Full crystallographic information is available from OCA.
Reference
Structural basis of nonnatural amino acid recognition by an engineered aminoacyl-tRNA synthetase for genetic code expansion., Kobayashi T, Sakamoto K, Takimura T, Sekine R, Kelly VP, Kamata K, Nishimura S, Yokoyama S, Proc Natl Acad Sci U S A. 2005 Feb 1;102(5):1366-71. Epub 2005 Jan 25. PMID:15671170
Page seeded by OCA on Thu Feb 21 15:33:43 2008
Categories: Escherichia coli | Single protein | Tyrosine--tRNA ligase | Kamata, K. | Kobayashi, T. | Nishimura, S. | RSGI, RIKEN Structural Genomics/Proteomics Initiative. | Sakamoto, K. | Sekine, R. | Takimura, T. | Yokoyama, S. | YSA | Ligase | Riken structural genomics/proteomics initiative | Rsgi | Structural genomics
