Structure of a C1/C4-oxidizing AA9 lytic polysaccharide monooxygenase from the thermophilic fungus Malbranchea cinnamomea
Scott Mazurkewich, Andrea Seveso, Silvia Hüttner, Gisela Brändén, Johan Larsbrink [1]
Molecular Tour
The thermophilic fungus Malbranchea cinnamomea encodes eight lytic polysaccharide monooxygenases (LPMOs) from the Auxiliary Activities family 9 (AA9), four of which have been shown to oxidatively cleave various polysaccharides. Here we solved the , which is a C1/C4-oxidizing LPMO able to cleave both crystalline and soluble glycans. The structure is colored from N- to C-terminus, blue to red. The copper ion and the residues coordinating it are shown. The position of the succinimide found in place of Asp10 in the loop between strands β1 and β2 is identified by a white arrow and the loops forming the flat surface comprising the substrate binding face are labelled (L2, L3, L8, LS, LC). The structure reveals that McAA9F has an overall similar fold as other solved AA9 enzymes, but also has different loop structures than what have previously been linked to activity on soluble oligosaccharides. The structure further contains a rare succinimide substitution that has not been seen in other LPMOs.
References
- ↑ Mazurkewich S, Seveso A, Huttner S, Branden G, Larsbrink J. Structure of a C1/C4-oxidizing AA9 lytic polysaccharide monooxygenase from the thermophilic fungus Malbranchea cinnamomea. Acta Crystallogr D Struct Biol. 2021 Aug 1;77(Pt 8):1019-1026. doi:, 10.1107/S2059798321006628. Epub 2021 Jul 29. PMID:34342275 doi:http://dx.doi.org/10.1107/S2059798321006628