Impact of the Copper Second Coordination Sphere on Catalytic Performance and Substrate Specificity of a Bacterial Lytic Polysaccharide Monooxygenase.

ABSTRACT: Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of glycosidic bonds in recalcitrant polysaccharides, such as cellulose and chitin, using a single copper cofactor bound in a conserved histidine brace with a more variable second coordination sphere. Cellulose-active LPMOs in the fungal AA9 family and in a subset of bacterial AA10 enzymes contain a His-Gln-Tyr second sphere motif, whereas other cellulose-active AA10s have an Arg-Glu-Phe motif. To shine a light on the impact of this variation, we generated single, double, and triple mutations changing the His²¹⁶-Gln²¹⁹-Tyr²²¹ motif in cellulose- and chitin-oxidizing MaAA10B toward Arg-Glu-Phe. These mutations generally reduced enzyme performance due to rapid inactivation under

SUBMITTER: Hall KR 

PROVIDER: S-EPMC11137697 | biostudies-literature | 2024 May

REPOSITORIES: biostudies-literature