2ayh
From Proteopedia
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CRYSTAL AND MOLECULAR STRUCTURE AT 1.6 ANGSTROMS RESOLUTION OF THE HYBRID BACILLUS ENDO-1,3-1,4-BETA-D-GLUCAN 4-GLUCANOHYDROLASE H(A16-M)
Overview
H(A16-M) is a hybrid endo-1,3-1,4-beta-D-glucan 4-glucanohydrolase from, Bacillus. Its crystal structure was refined using synchrotron X-ray, diffraction data up to a maximal resolution of 0.16 nm. The R value of the, resulting model is 14.3% against 21,032 reflections > 2 sigma. 93% of the, amino acid residues are in the most favorable regions of the Ramachandran, diagram, and geometrical parameters are in accordance with other proteins, solved at high resolution. As shown earlier [Keitel, T., Simon, O., Borriss, R. & Heinemann, U. (1993) Proc. Natl Acad. Sci. USA 90, 5287-5291], the protein folds into a compact jellyroll-type beta-sheet, structure. A systematic analysis of the secondary structure reveals the, presence of two major antiparallel beta-sheets and a three-stranded minor, mixed sheet. Amino acid residues involved in catalysis and substrate, binding are located inside a deep channel spanning the surface of the, protein. To investigate the stereochemical cause of the observed, specificity of endo-1,3-1,4-beta-D-glucan 4-glucanohydrolases towards, beta-1,4 glycosyl bonds adjacent to beta-1,3 bonds, the high-resolution, crystal structure has been used to model an enzyme-substrate complex. It, is proposed that productive substrate binding to the subsites p1, p2 and, p3 of H(A16-M) requires a beta-1,3 linkage between glucose units bound to, p1 and p2.
About this Structure
2AYH is a Single protein structure of sequence from Hibberdia with CA as ligand. This structure superseeds the now removed PDB entry 1AYH. Active as Licheninase, with EC number 3.2.1.73 Full crystallographic information is available from OCA.
Reference
Crystal and molecular structure at 0.16-nm resolution of the hybrid Bacillus endo-1,3-1,4-beta-D-glucan 4-glucanohydrolase H(A16-M)., Hahn M, Keitel T, Heinemann U, Eur J Biochem. 1995 Sep 15;232(3):849-58. PMID:7588726
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