Gene cloning, expression, and characterization of a thermostable xylanase from Nesterenkonia xinjiangensis CCTCC AA001025.
An endo-beta-1,4-xylanase-encoding gene, xyn11NX, was cloned from Nesterenkonia xinjiangensis CCTCC AA001025 and expressed in Escherichia coli. The gene encoded a 192-amino acid polypeptide and a putative 50-amino acid signal peptide. The deduced amino acid sequence exhibited a high degree of similarity with the xylanases from Streptomyces thermocyaneoviolaceus (68%) and Thermobifida fusca (66%) belonging to glycoside hydrolase family 11. After purification to homogeneity, the recombinant Xyn11NX exhibited optimal activity at pH 7.0 and 55 degrees C and remained stable at weakly acidic to alkaline pH (pH 5.0-11.0). The enzyme was thermostable, retaining more than 80% of the initial activity after incubation at 60 degrees C for 1 h and more than 40% of the activity at 90 degrees C for 15 min. The K (m) and V (max) values for oat spelt xylan and birchwood xylan were 16.08 mg ml(-1) and 45.66 micromol min(-1) mg(-1) and 9.22 mg ml(-1) and 16.05 micromol min(-1) mg(-1), respectively. The predominant hydrolysis products were xylobiose and xylotriose when using oat spelt xylan or birchwood xylan as substrate.
Kui
Hong
H
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.
Luo
Huiying
H
Shi
Pengjun
P
Bai
Yingguo
Y
Yuan
Tiezheng
T
Wang
Yaru
Y
Yang
Peilong
P
Dong
Shouliang
S
Yao
Bin
B
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008835:Micrococcaceae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment
D001426:Bacterial Proteins; D043364:Endo-1,4-beta Xylanases