2xim

ARGININE RESIDUES AS STABILIZING ELEMENTS IN PROTEINS

spinqualitylabelsall models 2xim, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2xim is a 4 chain structure with sequence from Actinoplanes missouriensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MG, XYL Activity: Xylose isomerase, with EC number 5.3.1.5 Resources: FirstGlance, OCA, 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 Site-specific substitutions of arginine for lysine in the thermostable D-xylose isomerase (XI) from Actinoplanes missouriensis are shown to impart significant heat stability enhancement in the presence of sugar substrates most probably by interfering with nonenzymatic glycation. The same substitutions are also found to increase heat stability in the absence of any sugar derivatives, where a mechanism based on prevention of glycation can no longer be invoked. This rather conservative substitution is moreover shown to improve thermostability in two other structurally unrelated proteins, human copper, zinc-superoxide dismutase (CuZnSOD) and D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Bacillus subtilis. The stabilizing effect of Lys----Arg substitutions is rationalized on the basis of a detailed analysis of the crystal structures of wild-type XI and of engineered variants with Lys----Arg substitution at four distinct locations, residues 253, 309, 319, and 323. Molecular model building analysis of the structures of wild-type and mutant CuZnSOD (K9R) and GAPDH (G281K and G281R) is used to explain the observed stability enhancement in these proteins. In addition to demonstrating that even thermostable proteins can lend themselves to further stability improvement, our findings provide direct evidence that arginine residues are important stabilizing elements in proteins. Moreover, the stabilizing role of electrostatic interactions, particularly between subunits in oligomeric proteins, is documented. Arginine residues as stabilizing elements in proteins.,Mrabet NT, Van den Broeck A, Van den brande I, Stanssens P, Laroche Y, Lambeir AM, Matthijssens G, Jenkins J, Chiadmi M, van Tilbeurgh H, et al. Biochemistry. 1992 Mar 3;31(8):2239-53. PMID:1540579 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also D-xylose isomerase

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