1vbn

Escherichia coli tyrosyl-tRNA synthetase mutant complexed with Tyr-AMS

spinqualitylabelsall models 1vbn, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1vbn is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: YSA Related: 1udf, 1udj, 1vbm Activity: Tyrosine--tRNA ligase, with EC number 6.1.1.1 Resources: FirstGlance, OCA, RCSB, PDBsum, TOPSAN Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA Synthetase

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