2YG1

APO STRUCTURE OF CELLOBIOHYDROLASE 1 (CEL7A) FROM HETEROBASIDION ANNOSUM

Summary for 2YG1

• Entry DOI: 10.2210/pdb2yg1/pdb
• Descriptor: CELLULOSE 1,4-BETA-CELLOBIOSIDASE, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: hydrolase, glycoside hydrolase, cellulase, white-rot fungus, basidiomycete, forest pathogen
• Biological source: HETEROBASIDION ANNOSUM
• Total number of polymer chains: 2
• Total formula weight: 94904.17

Authors

Haddad-Momeni, M.,Hansson, H.,Mikkelsen, N.E.,Wang, X.,Svedberg, J.,Sandgren, M.,Stahlberg, J. (deposition date: 2011-04-11, release date: 2012-04-25, Last modification date: 2024-11-06)

Primary citation

Momeni, M.H.,Payne, C.M.,Hansson, H.,Mikkelsen, N.E.,Svedberg, J.,Engstrom, A.,Sandgren, M.,Beckham, G.T.,Stahlberg, J.
Structural, Biochemical, and Computational Characterization of the Glycoside Hydrolase Family 7 Cellobiohydrolase of the Tree-Killing Fungus Heterobasidion Irregulare.
J.Biol.Chem., 288:5861-, 2013

PubMed Abstract: Root rot fungi of the Heterobasidion annosum complex are the most damaging pathogens in temperate forests, and the recently sequenced Heterobasidion irregulare genome revealed over 280 carbohydrate-active enzymes. Here, H. irregulare was grown on biomass, and the most abundant protein in the culture filtrate was identified as the only family 7 glycoside hydrolase in the genome, which consists of a single catalytic domain, lacking a linker and carbohydrate-binding module. The enzyme, HirCel7A, was characterized biochemically to determine the optimal conditions for activity. HirCel7A was crystallized and the structure, refined at 1.7 Å resolution, confirms that HirCel7A is a cellobiohydrolase rather than an endoglucanase, with a cellulose-binding tunnel that is more closed than Phanerochaete chrysosporium Cel7D and more open than Hypocrea jecorina Cel7A, suggesting intermediate enzyme properties. Molecular simulations were conducted to ascertain differences in enzyme-ligand interactions, ligand solvation, and loop flexibility between the family 7 glycoside hydrolase cellobiohydrolases from H. irregulare, H. jecorina, and P. chrysosporium. The structural comparisons and simulations suggest significant differences in enzyme-ligand interactions at the tunnel entrance in the -7 to -4 binding sites and suggest that a tyrosine residue at the tunnel entrance of HirCel7A may serve as an additional ligand-binding site. Additionally, the loops over the active site in H. jecorina Cel7A are more closed than loops in the other two enzymes, which has implications for the degree of processivity, endo-initiation, and substrate dissociation. Overall, this study highlights molecular level features important to understanding this biologically and industrially important family of glycoside hydrolases.

PubMed: 23303184
DOI: 10.1074/JBC.M112.440891

Experimental method

X-RAY DIFFRACTION (1.9 Å)