Skip to main content
SLU publication database (SLUpub)

Research article2004Peer reviewed

Crystal complex structures reveal how substrate is bound in the -4 to the +2 binding sites of Humicola grisea cel12A

Sandgren M, Berglund GI, Shaw A, Stahlberg J, Kenne L, Desmet T, Mitchinson C

Abstract

As part of an ongoing enzyme discovery program to investigate the properties and catalytic mechanism of glycoside hydrolase family 12 (GH 12) endoglucanases, a GH family that contains several cellulases that are of interest in industrial applications, we have solved four new crystal structures of wild-type Humicola grisea Cel12A in complexes formed by soaking with cellobiose, cellotetraose, cellopentaose, and a thio-linked cellotetraose derivative (G(2)SG(2)). These complex structures allow mapping of the non-covalent interactions between the enzyme and the glucosyl chain bound in subsites -4 to +2 of the enzyme, and shed light on the mechanism and function of GH 12 cellulases. The unhydrolysed cellopentaose and the G2SG2 cello-oligomers span the active site of the catalytically active H. grisea Cel12A enzyme, with the pyranoside bound in subsite -1 displaying a S-1(3) skew boat conformation. After soaking in cellotetraose, the cello-oligomer that is found bound in site -4 to -1 contains a beta-1,3-linkage between the two cellobiose units in the oligomer, which is believed to have been formed by a transglycosylation reaction that has occurred during the ligand soak of the protein crystals. The close fit of this ligand and the binding sites occupied suggest a novel mixed beta-glucanase activity for this enzyme. (C) 2004 Elsevier Ltd. All rights reserved

Published in

Journal of Molecular Biology
2004, Volume: 342, number: 5, pages: 1505-1517
Publisher: ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD

      SLU Authors

    • Ståhlberg, Jerry

      • Department of Molecular Biology, Swedish University of Agricultural Sciences

        • Sandgren, Mats

          • Department of Molecular Biology, Swedish University of Agricultural Sciences

        Publication identifier

        DOI: https://doi.org/10.1016/j.jmb.2004.07.098

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/3263