title: Determinants of regioselective hydroxylation in the fungal polysaccharide monooxygenases.
abstract: The ubiquitous fungal polysaccharide monooxygenases (PMOs) (also known as GH61 proteins, LPMOs, and AA9 proteins) are structurally related but have significant variation in sequence. A heterologous expression method in Neurospora crassa was developed as a step toward connecting regioselectivity of the chemistry to PMO phylogeny. Activity assays, as well as sequence and phylogenetic analyses, showed that the majority of fungal PMOs fall into three major groups with distinctive active site surface features. PMO1s and PMO2s hydroxylate glycosidic positions C1 and C4, respectively. PMO3s hydroxylate both C1 and C4. A subgroup of PMO3s (PMO3*) hydroxylate C1. Mutagenesis studies showed that an extra subdomain of about 12 amino acids contribute to C4 oxidation in the PMO3 family.
authors.affiliation: Department of Chemistry, The Scripps Research Institute , La Jolla, California 92037, United States.
authors.forename: Van V
authors.initials: VV
authors.lastname: Vu
authors.forename: William T
authors.initials: WT
authors.lastname: Beeson
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Phillips
authors.forename: Jamie H D
authors.initials: JH
authors.lastname: Cate
authors.forename: Michael A
authors.initials: MA
authors.lastname: Marletta
mesh_terms: D000595:Amino Acid Sequence; D002236:Carbohydrate Conformation; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006900:Hydroxylation; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000201:enzymology*; D010802:Phylogeny; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D013237:Stereoisomerism
chemical_list: D005656:Fungal Proteins; D011134:Polysaccharides; D006899:Mixed Function Oxygenases