Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAs 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 (G2SG2). 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 S31 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. 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 J Mol Biol. 2004 Oct 1;342(5):1505-17. PMID:15364577[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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