4pbt

Crystal structure of the M. jannaschii G2 tRNA synthetase variant bound to 4-trans-cyclooctene-amidopheylalanine (Tco-amF)

spinqualitylabelsall models 4pbt, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4pbt is a 1 chain structure with sequence from Methanocaldococcus jannaschii DSM 2661. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: 2LQ, GOL, P4G Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SYY_METJA 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). Publication Abstract from PubMed The site-specific incorporation of non-canonical amino acids (ncAAs) into proteins is an important tool for understanding biological function. Traditionally, each new ncAA targeted for incorporation requires a resource-consuming process of generating new ncAA aminoacyl tRNA synthetase/tRNACUA pairs. However, the discovery that some tRNA synthetases are "permissive", in that they can incorporate multiple ncAAs, means that it is no longer always necessary to develop a new synthetase for each newly desired ncAA. Developing a better understanding of what factors make ncAA synthetases more permissive would increase the utility of this new approach. Here, we characterized two synthetases selected for the same ncAA that have markedly different "permissivity profiles." Remarkably, the more permissive synthetase incorporated an ncAA for which we had not been able to generate a synthetase through de novo selection methods. Crystal structures revealed that the two synthetases recognize their parent ncAA through a conserved core of interactions, with the more permissive synthetase displaying a greater degree of flexibility in its interaction geometries. We also observed that intraprotein interactions not directly involved in ncAA binding can play a crucial role in synthetase permissivity and suggest that optimization of such interactions might provide an avenue to engineering synthetases with enhanced permissivity. Gleaning Unexpected Fruits from Hard-Won Synthetases: Probing Principles of Permissivity in Non-canonical Amino Acid-tRNA Synthetases.,Cooley RB, Karplus PA, Mehl RA Chembiochem. 2014 Jul 11. doi: 10.1002/cbic.201402180. PMID:25044993 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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