4mai
Structure of Aspergillus oryzae AA11 Lytic Polysaccharide Monooxygenase with Cu(I)
Structural highlights
FunctionLP11_ASPOR Lytic polysaccharide monooxygenase (LPMO) that depolymerizes chitin via the oxidation of scissile beta-(1-4)-glycosidic bonds, yielding C1 or C4 oxidation products (PubMed:24362702). Catalysis by LPMOs requires the reduction of the active-site copper from Cu(II) to Cu(I) by a reducing agent and H(2)O(2) or O(2) as a cosubstrate (PubMed:24362702). Active on chitin but has no activity on other substrates, including diverse mannans, cellulose and starch (data not shown) (PubMed:24362702). Primary chain cleavage yields predominantly aldonic acid oligosaccharides with even-numbered degrees of polymerization (PubMed:24362702).[1] Publication Abstract from PubMedLytic polysaccharide monooxygenases (LPMOs) are a recently discovered class of enzymes capable of oxidizing recalcitrant polysaccharides. They are attracting considerable attention owing to their potential use in biomass conversion, notably in the production of biofuels. Previous studies have identified two discrete sequence-based families of these enzymes termed AA9 (formerly GH61) and AA10 (formerly CBM33). Here, we report the discovery of a third family of LPMOs. Using a chitin-degrading exemplar from Aspergillus oryzae, we show that the three-dimensional structure of the enzyme shares some features of the previous two classes of LPMOs, including a copper active center featuring the 'histidine brace' active site, but is distinct in terms of its active site details and its EPR spectroscopy. The newly characterized AA11 family expands the LPMO clan, potentially broadening both the range of potential substrates and the types of reactive copper-oxygen species formed at the active site of LPMOs. Discovery and characterization of a new family of lytic polysaccharide monooxygenases.,Hemsworth GR, Henrissat B, Davies GJ, Walton PH Nat Chem Biol. 2014 Feb;10(2):122-6. doi: 10.1038/nchembio.1417. Epub 2013 Dec, 22. PMID:24362702[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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