Symbiotic Streptomyces sp. TN119 GH 11 xylanase: a new pH-stable, protease- and SDS-resistant xylanase.
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).
Zhou
Junpei
J
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.
Shi
Pengjun
P
Zhang
Rui
R
Huang
Huoqing
H
Meng
Kun
K
Yang
Peilong
P
Yao
Bin
B
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
D001426:Bacterial Proteins; D021382:Protein Sorting Signals; D012967:Sodium Dodecyl Sulfate; D043364:Endo-1,4-beta Xylanases; D010447:Peptide Hydrolases