title: Cloning and characterization of the xyn11A gene from Lentinula edodes.
abstract: Hemicellulose represents a rich source of biomass that can be converted into useful chemical feedstocks. One of the main components of hemicellulose is xylan, a polymer of xylose residues. Xylanase enzymes that hydrolyze xylan are therefore of great commercial interest. We have cloned a gene (xyn11A) that encodes a 283-amino acid xylanase enzyme from the fungus Lentinula edodes. The enzyme has a pI of 4.6 and belongs to the highly conserved glycosyl hydrolase family 11. The xylanase gene was cloned into a Pichia pastoris expression vector that secretes active enzyme into both solid and liquid media. The optimal reaction conditions were at pH 4.5 and 50 degrees C. The enzyme had a Km of 1.5 mg/ml and a Vmax of 2.1 mmol/min/mg. Xyn11A produced primarily xylobiose, xylotriose, and xylotetraose from a birchwood xylan substrate. This is the first report on the cloning of a hemicellulase gene from L. edodes.
authors.affiliation: Western Regional Research Center, USDA-ARS, Albany, CA 94710, USA. clee@pw.usda.gov
authors.forename: Charles C
authors.initials: CC
authors.lastname: Lee
authors.forename: Dominic W S
authors.initials: DW
authors.lastname: Wong
authors.forename: George H
authors.initials: GH
authors.lastname: Robertson
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020942:Shiitake Mushrooms / Q000201:enzymology / Q000235:genetics*; D013379:Substrate Specificity; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D014990:Xylans; D012313:RNA; D043364:Endo-1,4-beta Xylanases