2JKP

Structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron in complex with castanospermine

Summary for 2JKP

• Entry DOI: 10.2210/pdb2jkp/pdb
• Related: 2JKA 2JKE
• Descriptor: ALPHA-GLUCOSIDASE (ALPHA-GLUCOSIDASE SUSB), CASTANOSPERMINE, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: hydrolase, family 97, castanospermine, alpha-glucosidase, glycoside hydrolase, bacteroides thetaiotaomicron
• Biological source: BACTEROIDES THETAIOTAOMICRON
• Total number of polymer chains: 2
• Total formula weight: 167321.42

Authors

Gloster, T.M.,Turkenburg, J.P.,Potts, J.R.,Henrissat, B.,Davies, G.J. (deposition date: 2008-08-29, release date: 2008-09-30, Last modification date: 2023-12-13)

Primary citation

Gloster, T.M.,Turkenburg, J.P.,Potts, J.R.,Henrissat, B.,Davies, G.J.
Divergence of Catalytic Mechanism within a Glycosidase Family Provides Insight Into Evolution of Carbohydrate Metabolism by Human Gut Flora.
Chem.Biol., 15:1058-, 2008

PubMed Abstract: Enzymatic cleavage of the glycosidic bond yields products in which the anomeric configuration is either retained or inverted. Each mechanism reflects the dispositions of the enzyme functional groups; a facet of which is essentially conserved in 113 glycoside hydrolase (GH) families. We show that family GH97 has diverged significantly, as it contains both inverting and retaining alpha-glycosidases. This reflects evolution of the active center; a glutamate acts as a general base in inverting members, exemplified by Bacteroides thetaiotaomicron alpha-glucosidase BtGH97a, whereas an aspartate likely acts as a nucleophile in retaining members. The structure of BtGH97a and its complexes with inhibitors, coupled to kinetic analysis of active-site variants, reveals an unusual calcium ion dependence. 1H NMR analysis shows an inversion mechanism for BtGH97a, whereas another GH97 enzyme from B. thetaiotaomicron, BtGH97b, functions as a retaining alpha-galactosidase.

PubMed: 18848471
DOI: 10.1016/J.CHEMBIOL.2008.09.005

Experimental method

X-RAY DIFFRACTION (1.99 Å)