1H8V

The X-ray Crystal Structure of the Trichoderma reesei Family 12 Endoglucanase 3, Cel12A, at 1.9 A Resolution

Summary for 1H8V

• Entry DOI: 10.2210/pdb1h8v/pdb
• Related: 1OA2 1OLQ
• Descriptor: ENDO-BETA-1,4-GLUCANASE, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: hydrolase, cellulase, cellulose degradation, gh family 12, glycosyl hydrolase
• Biological source: TRICHODERMA REESEI
• Total number of polymer chains: 6
• Total formula weight: 142167.30

Authors

Sandgren, M.,Shaw, A.,Ropp, T.H.,Wu, S.,Bott, R.,Cameron, A.D.,Stahlberg, J.,Mitchinson, C.,Jones, T.A. (deposition date: 2001-02-16, release date: 2001-04-24, Last modification date: 2024-10-16)

Primary citation

Sandgren, M.,Shaw, A.,Ropp, T.H.,Wu, S.,Bott, R.,Cameron, A.D.,Stahlberg, J.,Mitchinson, C.,Jones, T.A.
The X-Ray Crystal Structure of the Trichoderma Reesei Family 12 Endoglucanase 3, Cel12A, at 1.9 A Resolution
J.Mol.Biol., 308:295-, 2001

PubMed Abstract: We present the three-dimensional structure of Trichoderma reesei endoglucanase 3 (Cel12A), a small, 218 amino acid residue (24.5 kDa), neutral pI, glycoside hydrolase family 12 cellulase that lacks a cellulose-binding module. The structure has been determined using X-ray crystallography and refined to 1.9 A resolution. The asymmetric unit consists of six non-crystallographic symmetry-related molecules that were exploited to improve initial multiple isomorphous replacement phasing, and subsequent structure refinement. The enzyme contains one disulfide bridge and is glycosylated at Asp164 by a single N-acetyl glucosamine residue. The protein has the expected fold for a glycoside hydrolase clan-C family 12 enzyme. It contains two beta-sheets, of six and nine strands, packed on top of one another, and one alpha-helix. The concave surface of the nine-stranded beta-sheet forms a large substrate-binding groove in which the active-site residues are located. In the active site, we find a carboxylic acid trio, similar to that of glycoside hydrolase families 7 and 16. The strictly conserved Asp99 hydrogen bonds to the nucleophile, the invariant Glu116. The binding crevice is lined with both aromatic and polar amino acid side-chains which may play a role in substrate binding. The structure of the fungal family 12 enzyme presented here allows a complete structural characterization of the glycoside hydrolase-C clan.

PubMed: 11327768
DOI: 10.1006/JMBI.2001.4583

Experimental method

X-RAY DIFFRACTION (1.9 Å)