1i6k | pdb_00001i6k

1.7 HIGH RESOLUTION EXPERIMENTAL PHASES FOR TRYPTOPHANYL-TRNA SYNTHETASE COMPLEXED WITH TRYPTOPHANYL-5'AMP

spinqualitylabelsall models 1i6k, resolution 1.72Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1i6k is a 1 chain structure with sequence from Geobacillus stearothermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GOL, NH4, SO4, TYM NonStd Res: MSE Activity: Tryptophan--tRNA ligase, with EC number 6.1.1.2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum 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 Native data, anomalous data at three wavelengths and an independent peak-wavelength data set for SeMet-substituted protein have been collected from cryoprotected crystals of the TrpRS-adenylate product (TAM) complex to a resolution limit of 1.7 A. Independent phase sets were developed using SHARP and improved by solvent flipping with SOLOMON using molecular envelopes derived from experimental densities for, respectively, peak-wavelength SAD data from four different crystals, MAD data and their M(S)IRAS combinations with native data. Hendrickson-Lattman phase-probability coefficients from each phase set were used in BUSTER to drive maximum-likelihood refinements of well defined parts of the previously refined room-temperature 2.9 A structure. Maximum-entropy completion followed by manual rebuilding was then used to generate a model for the missing segments, bound ligand and solvent molecules. Surprisingly, peak-wavelength SAD experiments produced the smallest phase errors relative to the refined structures. Selenomethionylated models deviate from one another by 0.25 A and from the native model by 0.38 A, but all have r.m.s. deviations of approximately 1.0 A from the 2.9 A model. Difference Fourier calculations between amplitudes from the 300 K experiment and the new amplitudes at 100 K using 1.7 A model phases show no significant structural changes arising from temperature variation or addition of cryoprotectant. The main differences between low- and high-resolution structures arise from correcting side-chain rotamers in the core of the protein as well as on the surface. These changes improve various structure-validation criteria. High-resolution experimental phases for tryptophanyl-tRNA synthetase (TrpRS) complexed with tryptophanyl-5'AMP.,Retailleau P, Yin Y, Hu M, Roach J, Bricogne G, Vonrhein C, Roversi P, Blanc E, Sweet RM, Carter CW Jr Acta Crystallogr D Biol Crystallogr. 2001 Nov;57(Pt 11):1595-608. Epub, 2001 Oct 25. PMID:11679724 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA Synthetase

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