title: Symbiotic Streptomyces sp. TN119 GH 11 xylanase: a new pH-stable, protease- and SDS-resistant xylanase.
abstract: A pH-stable and protease-resistant xylanase (XynB119) was identified from Streptomyces sp. TN119, a strain isolated from the gut luminal contents of longhorned beetle (Batocera horsfieldi) larvae. Using the GC TAIL-PCR method, the 1,026-bp coding gene (xynB119) with 67.3% GC content was successfully cloned and expressed in Escherichia coli. It encodes a 341-residue polypeptide with a calculated molecular mass of 35.9 kDa, including a putative 41-residue signal peptide, a catalytic domain of glycosyl hydrolase (GH) family 11, a short Gly/Pro-rich linker, and a family 2 cellulose-binding domain (CBM 2). The deduced amino acid sequence is most similar to (61.9% identity) an endo-1,4-β-xylanase from Streptomyces thermoviolaceus OPC-520. Purified recombinant XynB119 exhibited peak activity at 50 °C and pH 7.0, remained stable over a broad pH range (retaining >70% activity after incubation at pH 1.0-11.0 for 1 h at 37 °C without substrate), had strong protease resistance (retaining >90% activity after proteolytic treatment at 37 °C for 1 h) and SDS resistance (at 100 mM). These properties make XynB119 promising for application in the feed industry and valuable for basic research. Compared to r-XynB119, the r-XynB119 derivative without CBM 2 and linker region (r-XynB119d) exhibited a decreased pH stability of >25% at extreme pHs (pH 1.0-3.0 and pH 11.0-12.0).
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing 100081, People's Republic of China.
authors.forename: Junpei
authors.initials: J
authors.lastname: Zhou
authors.forename: Pengjun
authors.initials: P
authors.lastname: Shi
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Huoqing
authors.initials: H
authors.lastname: Huang
authors.forename: Kun
authors.initials: K
authors.lastname: Meng
authors.forename: Peilong
authors.initials: P
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001482:Base Composition; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000378:metabolism; D021382:Protein Sorting Signals / Q000235:genetics; D016415:Sequence Alignment; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D021382:Protein Sorting Signals; D012967:Sodium Dodecyl Sulfate; D043364:Endo-1,4-beta Xylanases; D010447:Peptide Hydrolases