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Publication Abstract from PubMed

Crystal structures of a beta-1,3-glucanase from the thermophilic fungus Chaetomium thermophilum were determined at 1.20 and 1.42A resolution in the free and glucose-bound form, respectively. This is the third structure of a family 55 glycoside hydrolase (GH55) member and the second from a fungus. Based on comparative structural studies and site-directed mutagenesis, Glu654 is proposed as the catalytic acid residue. The substrate binding cleft exhibits restricted access on one side, rendering the enzyme as an exo-beta-1,3-glucanase as confirmed also by thin layer chromatography experiments. A lack of stacking interactions was found at the substrate binding cleft, suggesting that interactions at positions -1, +1 and +2 are sufficient to orientate the substrate. A binding pocket was identified that could explain binding of branched laminarin and accumulation of laminaritriose.

Crystal structure and biological implications of a glycoside hydrolase family 55 beta-1,3-glucanase from Chaetomium thermophilum.,Papageorgiou AC, Chen J, Li D Biochim Biophys Acta. 2017 May 4. pii: S1570-9639(17)30084-5. doi:, 10.1016/j.bbapap.2017.05.002. PMID:28479293^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.