1AYX
CRYSTAL STRUCTURE OF GLUCOAMYLASE FROM SACCHAROMYCOPSIS FIBULIGERA AT 1.7 ANGSTROMS
Summary for 1AYX
| Entry DOI | 10.2210/pdb1ayx/pdb |
| Descriptor | GLUCOAMYLASE, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL (3 entities in total) |
| Functional Keywords | glucoamylase, hydrolase, glycosidase, polysaccharide degradation |
| Biological source | Saccharomycopsis fibuligera |
| Total number of polymer chains | 1 |
| Total formula weight | 54782.11 |
| Authors | Sevcik, J.,Hostinova, E.,Gasperik, J.,Solovicova, A.,Wilson, K.S.,Dauter, Z. (deposition date: 1997-11-12, release date: 1998-05-13, Last modification date: 2024-02-07) |
| Primary citation | Sevcik, J.,Solovicova, A.,Hostinova, E.,Gasperik, J.,Wilson, K.S.,Dauter, Z. Structure of glucoamylase from Saccharomycopsis fibuligera at 1.7 A resolution. Acta Crystallogr.,Sect.D, 54:854-866, 1998 Cited by PubMed Abstract: The yeast Saccharomycopsis fibuligera produces a glucoamylase which belongs to sequence family 15 of glycosyl hydrolases. The structure of the non-glycosyl-ated recombinant enzyme has been determined by molecular replacement and refined against 1.7 A resolution synchrotron data to an R factor of 14.6%. This is the first report of the three-dimensional structure of a yeast family 15 glucoamylase. The refinement from the initial molecular-replacement model was not straightforward. It involved the use of an unrestrained automated refinement procedure (uARP) in combination with the maximum-likelihood refinement program REFMAC. The enzyme consists of 492 amino-acid residues and has 14 alpha-helices, 12 of which form an (alpha/alpha)6 barrel. It contains a single catalytic domain but no starch-binding domain. The fold of the molecule and the active site are compared to the known structure of the catalytic domain of a fungal family 15 glucoamylase and are shown to be closely similar. The active- and specificity-site residues are especially highly conserved. The model of the acarbose inhibitor from the analysis of the fungal enzyme fits tightly into the present structure. The active-site topology is a pocket and hydrolysis proceeds with inversion of the configuration at the anomeric carbon. The enzyme acts as an exo-glycosyl hydrolase. There is a Tris [2-amino-2-(hydroxymethyl)-1,3-propanediol] molecule acting as an inhibitor in the active-site pocket. PubMed: 9757101DOI: 10.1107/S0907444998002005 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.7 Å) |
Structure validation
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