X-Ray Crystal Structures of Phanerochaete Chrysosporium Laminarinase 16A in Complex with Products from Lichenin and Laminarin Hydrolysis
Vasur, J., Kawai, R., Andersson, E., Igarashi, K., Sandgren, M., Samejima, M., Stahlberg, J.(2009) FEBS J 276: 3858
- PubMed: 19769746 
- DOI: https://doi.org/10.1111/j.1742-4658.2009.07099.x
- Primary Citation of Related Structures:  
2W39, 2W52 - PubMed Abstract: 
The 1,3(4)-beta-D-glucanases of glycoside hydrolase family 16 provide useful examples of versatile yet specific protein-carbohydrate interactions. In the present study, we report the X-ray structures of the 1,3(4)-beta-D-glucanase Phanerochaete chrysosporium Laminarinase 16A in complex with beta-glucan products from laminarin (1.6 A) and lichenin (1.1 A) hydrolysis. The G6G3G3G glucan, in complex with the enzyme, showed a beta-1,6 branch in the acceptor site. The G4G3G ligand-protein complex showed that there was no room for a beta-1,6 branch in the -1 or -2 subsites; furthermore, the distorted residue in the -1 subsite and the glucose in the -2 subsite required a beta-1,3 bond between them. These are the first X-ray crystal structures of any 1,3(4)-beta-D-glucanase in complex with glucan products. They provide details of both substrate and product binding in support of earlier enzymatic evidence.
Organizational Affiliation: 
Department of Molecular Biology, University of Agricultural Sciences, Uppsala, Sweden.