Lytic polysaccharide monooxygenases (LPMOs) boost enzymatic depolymerization of recalcitrant polysaccharides, such as chitin and cellulose. We have studied a chitin-active LPMO domain (JdLPMO10A) that is considerably smaller (15.5 kDa) than all structurally characterized LPMOs so far and that is part of a modular protein containing a GH18 chitinase. The 1.55 Å resolution structure revealed deletions of interacting loops that protrude from the core β-sandwich scaffold in larger LPMO10s. Despite these deletions, the enzyme is active on alpha- and beta-chitin, and the chitin-binding surface previously described for larger LPMOs is fully conserved. JdLPMO10A may represent a minimal scaffold needed to catalyse the powerful LPMO reaction.
Bibliographical noteFunding Information:
This work was supported by The Research Council of Norway through grants 214138 and 221576 and by the Vista programme of the Norwegian Academy of Science and Letters (grant 6510). We are grateful for synchrotron travel support from The Research Council of Norway (216625/F50) and support from the South- Eastern Norway Regional Health Authority (Grants No. 2012085 and 2015095; Regional Core Facility for Structural Biology to BD). We also thank the European Synchrotron Radiation Facility staff for help and beamtime at beamline ID29 (project MX-1468).
- Jonesia denitrificans
- lytic polysaccharide monooxygenase