4C4D

Covalent glycosyl-enzyme intermediate of Hypocrea jecorina Cel7a E217Q mutant trapped using DNP-2-deoxy-2-fluoro-cellotrioside

Summary for 4C4D

• Entry DOI: 10.2210/pdb4c4d/pdb
• Related: 4C4C
• Related PRD ID: PRD_900005
• Descriptor: CELLULOSE 1,4-BETA-CELLOBIOSIDASE, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-2-deoxy-2-fluoro-alpha-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: hydrolase, glycoside hydrolase, cellobiohydrolase, cellulase.
• Biological source: TRICHODERMA REESEI
• Total number of polymer chains: 1
• Total formula weight: 48128.24

Authors

Haddad-Momeni, M.,Mackenzie, L.,Sandgren, M.,Withers, S.G.,Stahlberg, J. (deposition date: 2013-09-05, release date: 2014-01-08, Last modification date: 2024-10-16)

Primary citation

Knott, B.C.,Haddad Momeni, M.,Crowley, M.F.,Mackenzie, L.F.,Gotz, A.W.,Sandgren, M.,Withers, S.G.,Stahlberg, J.,Beckham, G.T.
The Mechanism of Cellulose Hydrolysis by a Two-Step, Retaining Cellobiohydrolase Elucidated by Structural and Transition Path Sampling Studies.
J.Am.Chem.Soc., 136:321-, 2014

PubMed Abstract: Glycoside hydrolases (GHs) cleave glycosidic linkages in carbohydrates, typically via inverting or retaining mechanisms, the latter of which proceeds via a two-step mechanism that includes formation of a glycosyl-enzyme intermediate. We present two new structures of the catalytic domain of Hypocrea jecorina GH Family 7 cellobiohydrolase Cel7A, namely a Michaelis complex with a full cellononaose ligand and a glycosyl-enzyme intermediate, that reveal details of the 'static' reaction coordinate. We also employ transition path sampling to determine the 'dynamic' reaction coordinate for the catalytic cycle. The glycosylation reaction coordinate contains components of forming and breaking bonds and a conformational change in the nucleophile. Deglycosylation proceeds via a product-assisted mechanism wherein the glycosylation product, cellobiose, positions a water molecule for nucleophilic attack on the anomeric carbon of the glycosyl-enzyme intermediate. In concert with previous structures, the present results reveal the complete hydrolytic reaction coordinate for this naturally and industrially important enzyme family.

PubMed: 24341799
DOI: 10.1021/JA410291U

Experimental method

X-RAY DIFFRACTION (1.32 Å)