title: Purification and properties of family-10 endo-1,4-beta-xylanase from Penicillium citrinum and structural organization of encoding gene.
abstract: An extracellular endo-1,4-beta-xylanase was purified from the culture filtrate of a filamentous fungus, Penicillium citrinum strain FERM P-15944, grown on birch-wood xylan. The purified enzyme showed a single band on SDS-PAGE with an apparent M(r) of 31.6 kDa. The xylanase activity was optimal at pH 6.0 and 50 degrees C. Southern blot analysis indicated that the xylanase gene (xynB) was present as a single copy in the genome. The genomic DNA and cDNAs encoding this protein were cloned and sequenced. An open reading frame of xynB was interrupted by nine introns and encoded a presumed prepropeptide of 25 amino acids and a mature protein of 302 amino acids. Sequence alignment and the constructed neighbor-joining tree showed that the P. citrinum enzyme belongs to glycoside hydrolase family 10 and is closely related to several other xylanases from penicillia and black aspergilli. The xynB cDNA was functionally expressed in the methylotrophic yeast Pichia pastoris.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Wakiyama
authors.forename: Hidenori
authors.initials: H
authors.lastname: Tanaka
authors.forename: Koji
authors.initials: K
authors.lastname: Yoshihara
authors.forename: Sachio
authors.initials: S
authors.lastname: Hayashi
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ohta
mesh_terms: D000595:Amino Acid Sequence; D029662:Betula / Q000737:chemistry; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D005800:Genes, Fungal; D016366:Open Reading Frames; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D010843:Pichia / Q000235:genetics / Q000254:growth & development; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D014990:Xylans / Q000737:chemistry; D001617:beta-Glucosidase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D005656:Fungal Proteins; D011994:Recombinant Proteins; D014990:Xylans; D001617:beta-Glucosidase; D043364:Endo-1,4-beta Xylanases; C090001:XynB xylanase