1ukp

Crystal structure of soybean beta-amylase mutant substituted at surface region

spinqualitylabelsall models 1ukp, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ukp is a 4 chain structure with sequence from Glycine max. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AMYB_SOYBN 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 In spite of the high similarity of amino acid sequence and three-dimensional structure between soybean beta-amylase (SBA) and sweet potato beta-amylase (SPB), their quaternary structure is quite different, being a monomer in SBA and a tetramer in SPB. Because most of the differences in amino acid sequences are found in the surface region, we tested the tetramerization of SBA by examining mutations of residues located at the surface. We designed the SBA tetramer using the SPB tetramer structure as a model and calculating the change of accessible surface area (DeltaASA) for each residue in order to select sites for the mutation. Two different mutant genes encoding SB3 (D374Y/L481R/P487D) and SB4 (K462S added to SB3), were constructed for expression in Escherichia coli and the recombinant proteins were purified. They existed as a monomer in solution, but gave completely different crystals from the native SBA. The asymmetric unit of the mutants contains four molecules, while that of native SBA contains one. The interactions of the created interfaces revealed that there were more intermolecular interactions in the SB3 than in the SB4 tetramer. The substituted charged residues on the surface are involved in interactions with adjacent molecules in a different way, forming a new crystal packing pattern. Change in the crystal packing of soybean beta-amylase mutants substituted at a few surface amino acid residues.,Kang YN, Adachi M, Mikami B, Utsumi S Protein Eng. 2003 Nov;16(11):809-17. PMID:14631070 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Amylase 3D structures

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