1bww
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BENCE-JONES IMMUNOGLOBULIN REI VARIABLE PORTION, T39K MUTANT
OverviewOverview
The X-ray structure of the T39K mutant of the variable domain of a human, immunoglobulin kappa light chain has been determined at room temperature, to 1.7 A resolution with a conventional R factor of 0. 182. T39K, crystallizes in the triclinic space group P1 [a = 35.4 (1), b = 40.1 (1), c = 43.1 (1) A, alpha = 66.9 (1), beta = 85.4 (1), gamma = 73.8 (1), degrees ]. The unit-cell contains two monomers, related by a, non-crystallographic twofold axis. The use of a novel type of local, non-crystallographic symmetry restraints on related isotropic displacement, parameters and 1-4 distances as incorporated in the refinement program, SHELXL improves the model and quality of the maps, but local differences, between both monomers in areas subject to different packing contacts can, still be observed. 12 overall anisotropic scaling parameters were refined., These may have compensated for the difficulties in accurately scaling, single rotation axis image plate data from a triclinic crystal, because of, the scarcity of common equivalent reflections. The final model has been, used to perform a number of tests on anisotropic scaling, non-crystallographic symmetry, anisotropic refinement, determination of, standard uncertainties and bulk solvent correction. It is remarkable that, removal of the NCS restraints from the final model caused Rfree to, increase. These tests clarify the strategies for optimum use of SHELXL for, refinement at medium as opposed to atomic resolution.
About this StructureAbout this Structure
1BWW is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
1.7 A structure of the stabilized REIv mutant T39K. Application of local NCS restraints., Uson I, Pohl E, Schneider TR, Dauter Z, Schmidt A, Fritz HJ, Sheldrick GM, Acta Crystallogr D Biol Crystallogr. 1999 Jun;55(Pt 6):1158-67. PMID:10329778
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