title: Cloning, characterization and phylogenetic relationships of stxI, a endoxylanase-encoding gene from Streptomyces thermonitrificans NTU-88.
abstract: A thermostable xylanase gene (stxI) obtained from Streptomyces thermonitrificans NTU-88 on domain analysis revealed an N-terminal catalytic domain featuring homology to a known xylanase within the glycoside hydrolase family 11. Recombinant STXI retained more than 60% of its activity following its incubation for at 60 degrees C for 24h. These characteristics were close to thermophile and mesophile Streptomyces strains. The main hydrolysis products of xylan degraded by STXI included large xylooligosaccharide fragments. These results indicated that STXI was a typical endoxylanase. As regards the phylogenetic relationships of GH11, STXI and the other xylanase deriving from Streptomyces were included in a subgroup of the aerobic bacterial group. This result implied that the evolutionary relationships between the various xylanases deriving from Streptomyces strains were convergent.
authors.affiliation: Institute of Biotechnology, National Pingtung University of Science and Technology, Pingtung, Taiwan, ROC.
authors.forename: Hsueh-Ling
authors.initials: HL
authors.lastname: Cheng
authors.forename: Pei-Min
authors.initials: PM
authors.lastname: Wang
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Chen
authors.forename: Shang-Shyng
authors.initials: SS
authors.lastname: Yang
authors.forename: Yo-Chia
authors.initials: YC
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D001420:Bacteria, Aerobic / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001482:Base Composition; D001483:Base Sequence; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D043364:Endo-1,4-beta Xylanases; D004795:Enzyme Stability; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D043364:Endo-1,4-beta Xylanases