Cloning and characterization of the xyn11A gene from Lentinula edodes

• Published in: The Protein Journal 2005-01, Vol.24 (1), p.21-26
• Main Authors: Lee, Charles C, Wong, Dominic W S, Robertson, George H
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Bacteria; Base Sequence; Cloning; Cloning, Molecular; Endo-1,4-beta Xylanases - chemistry; Endo-1,4-beta Xylanases - genetics; Endo-1,4-beta Xylanases - isolation & purification; Endo-1,4-beta Xylanases - metabolism; Enzymes; Hydrogen-Ion Concentration; Lentinula edodes; Microbiology; Molecular Sequence Data; Pichia pastoris; Polymers; RNA - genetics; RNA - metabolism; Sequence Homology, Amino Acid; Shiitake Mushrooms - enzymology; Shiitake Mushrooms - genetics; Substrate Specificity; Temperature; Xylans - metabolism
• ISSN: 1572-3887; 1875-8355; 1573-4943
• DOI: 10.1007/s10930-004-0602-0

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.