title: Isolation and characterization of a novel GH67 α-glucuronidase from a mixed culture.
abstract: Hemicelluloses represent a large reservoir of carbohydrates that can be utilized for renewable products. Hydrolysis of hemicellulose into simple sugars is inhibited by its various chemical substituents. The glucuronic acid substituent is removed by the enzyme α-glucuronidase. A gene (deg75-AG) encoding a putative α-glucuronidase enzyme was isolated from a culture of mixed compost microorganisms. The gene was subcloned into a prokaryotic vector, and the enzyme was overexpressed and biochemically characterized. The DEG75-AG enzyme had optimum activity at 45 °C. Unlike other α-glucuronidases, the DEG75-AG had a more basic pH optimum of 7-8. When birchwood xylan was used as substrate, the addition of DEG75-AG increased hydrolysis twofold relative to xylanase alone.
authors.affiliation: USDA-ARS-WRRC, Albany, CA 94710, USA. Charles.Lee@ars.usda.gov
authors.forename: Charles C
authors.initials: CC
authors.lastname: Lee
authors.forename: Rena E
authors.initials: RE
authors.lastname: Kibblewhite
authors.forename: Kurt
authors.initials: K
authors.lastname: Wagschal
authors.forename: Ruiping
authors.initials: R
authors.lastname: Li
authors.forename: George H
authors.initials: GH
authors.lastname: Robertson
authors.forename: William J
authors.initials: WJ
authors.lastname: Orts
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism; D004926:Escherichia coli; D020723:Glucuronic Acid / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000378:metabolism; D012988:Soil Microbiology; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D011134:Polysaccharides; D014990:Xylans; C007916:hemicellulose; D020723:Glucuronic Acid; D006026:Glycoside Hydrolases; C096734:alpha-glucuronidase; D043364:Endo-1,4-beta Xylanases