1EXP

BETA-1,4-GLYCANASE CEX-CD

Summary for 1EXP

• Entry DOI: 10.2210/pdb1exp/pdb
• Related PRD ID: PRD_900050
• Descriptor: BETA-1,4-D-GLYCANASE CEX-CD, beta-D-glucopyranose-(1-4)-2-deoxy-2-fluoro-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: cellulose degradation, hydrolase, glycosidase
• Biological source: Cellulomonas fimi
• Total number of polymer chains: 1
• Total formula weight: 34396.23

Authors

White, A.,Tull, D.,Johns, K.L.,Withers, S.G.,Rose, D.R. (deposition date: 1996-01-11, release date: 1997-01-27, Last modification date: 2024-11-06)

Primary citation

White, A.,Tull, D.,Johns, K.,Withers, S.G.,Rose, D.R.
Crystallographic observation of a covalent catalytic intermediate in a beta-glycosidase.
Nat.Struct.Biol., 3:149-154, 1996

PubMed Abstract: The three-dimensional structure of a catalytically competent glycosyl-enzyme intermediate of a retaining beta-1,4-glycanase has been determined at a resolution of 1.8 A by X-ray diffraction. A fluorinated slow substrate forms an alpha-D-glycopyranosyl linkage to one of the two invariant carboxylates, Glu 233, as supported in solution by 19F-NMR studies. The resulting ester linkage is coplanar with the cyclic oxygen of the proximal saccharide and is inferred to form a strong hydrogen bond with the 2-hydroxyl of that saccharide unit in natural substrates. The active-site architecture of this covalent intermediate gives insights into both the classical double-displacement catalytic mechanism and the basis for the enzyme's specificity.

PubMed: 8564541
DOI: 10.1038/nsb0296-149

Experimental method

X-RAY DIFFRACTION (1.8 Å)