1GZ1

Mutant D416A of the CELLOBIOHYDROLASE CEL6A FROM HUMICOLA INSOLENS in complex with methyl-cellobiosyl-4-deoxy-4-thio-beta-D-cellobioside

Summary for 1GZ1

• Entry DOI: 10.2210/pdb1gz1/pdb
• Related: 1BVW 1HGW 1HGY 1OC5 1OC6 1OC7 1OCB 1OCJ 1OCN 1QJW 1QK0 1QK2 2BVW
• Descriptor: CELLOBIOHYDROLASE II, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-4-thio-beta-D-glucopyranose-(1-4)-methyl beta-D-glucopyranoside, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: hydrolase, cellulose degradation, cellobiohydrolase, cellulase, glycoside hydrolase family 6, thiooligosaccharide
• Biological source: HUMICOLA INSOLENS
• Total number of polymer chains: 1
• Total formula weight: 40891.33

Authors

Varrot, A.,Frandsen, T.,Driguez, H.,Davies, G.J. (deposition date: 2002-05-13, release date: 2003-02-12, Last modification date: 2024-10-09)

Primary citation

Varrot, A.,Frandsen, T.,Driguez, H.,Davies, G.J.
Structure of the Humicola Insolens Cellobiohydrolase Cel6A D416A Mutant in Complex with a Non-Hydrolysable Substrate Analogue, Methyl Cellobiosyl-4-Thio-Beta-Cellobioside, at 1.9 A
Acta Crystallogr.,Sect.D, 58:2201-, 2002

PubMed Abstract: The enzymatic degradation of cellulose continues to be one of the most important enzyme-catalysed reactions. Glycoside hydrolases from family GH-6 hydrolyse cellulose with inversion of the configuration of the anomeric carbon. Whilst the catalytic proton donor has been clearly identified (Asp226 in Humicola insolens Cel6A), the identification and even the existence of a potential Brønsted base remains unclear. Equally controversial is the role of surface-loop flexibility. Here, the structure of the D416A mutant of the H. insolens cellobiohydrolase Cel6A in complex with a non-hydrolysable thiooligosaccharide methyl cellobiosyl-4-thio-beta-cellobioside at 1.9 A resolution is presented. Substrate distortion in the -1 subsite, to a (2)S(0) skew-boat conformation, is observed, similar to that seen in the analogous Trichoderma reesei Cel6A structure [Zou et al. (1999), Structure, 7, 1035-1045], but the active-centre N-terminal loop of the H. insolens enzyme is found in a more open conformation than described for previous structures.

PubMed: 12454501
DOI: 10.1107/S0907444902017006

Experimental method

X-RAY DIFFRACTION (1.9 Å)