1h4v

HISTIDYL-TRNA SYNTHETASE from Thermus Thermophilus (ligand free)

spinqualitylabelsall models 1h4v, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1h4v is a 1 chain structure with sequence from Thermus thermophilus HB27. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.4Å Ligands: SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SYH_THET2 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 We describe the recognition by Thermus thermophilus prolyl-tRNA synthetase (ProRSTT) of proline, ATP and prolyl-adenylate and the sequential conformational changes occurring when the substrates bind and the activated intermediate is formed. Proline and ATP binding cause respectively conformational changes in the proline binding loop and motif 2 loop. However formation of the activated intermediate is necessary for the final conformational ordering of a ten residue peptide ("ordering loop") close to the active site which would appear to be essential for functional tRNA 3' end binding. These induced fit conformational changes ensure that the enzyme is highly specific for proline activation and aminoacylation. We also present new structures of apo and AMP bound histidyl-tRNA synthetase (HisRS) from T. thermophilus which we compare to our previous structures of the histidine and histidyl-adenylate bound enzyme. Qualitatively, similar results to those observed with T. thermophilus prolyl-tRNA synthetase are found. However histidine binding is sufficient to induce the co-operative ordering of the topologically equivalent histidine binding loop and ordering loop. These two examples contrast with most other class II aminoacyl-tRNA synthetases whose pocket for the cognate amino acid side-chain is largely preformed. T. thermophilus prolyl-tRNA synthetase appears to be the second class II aminoacyl-tRNA synthetase, after HisRS, to use a positively charged amino acid instead of a divalent cation to catalyse the amino acid activation reaction. A succession of substrate induced conformational changes ensures the amino acid specificity of Thermus thermophilus prolyl-tRNA synthetase: comparison with histidyl-tRNA synthetase.,Yaremchuk A, Tukalo M, Grotli M, Cusack S J Mol Biol. 2001 Jun 15;309(4):989-1002. PMID:11399074 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA synthetase 3D structures

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