1uu6
From Proteopedia
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X-RAY CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF HUMICOLA GRISEA CEL12A IN COMPLEX WITH A SOAKED CELLOPENTAOSE
Overview
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 (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.
About this Structure
1UU6 is a Single protein structure of sequence from Humicola grisea with as ligand. Active as Cellulase, with EC number 3.2.1.4 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Thu Feb 21 15:28:19 2008
