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. Method: X-ray diffraction, Resolution 2.7Å Ligands: YSA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT, TOPSAN Function SYY_ECOLI Catalyzes the attachment of tyrosine to tRNA(Tyr) in a two-step reaction: tyrosine is first activated by ATP to form Tyr-AMP and then transferred to the acceptor end of tRNA(Tyr).[HAMAP-Rule:MF_02006] 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 3D structures

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