Characterization of a thermostable xylanase from an alkaliphilic Bacillus sp.
A xylanase gene (xyn10) from alkaliphilic Bacillus sp. N16-5 was cloned and expressed in Pichia pastoris. The deduced amino acid sequence has 85% identity with xylanase xyn10A from B. halodurans and contains two potential N-glycosylation sites. The glycosylated Xyn10 with MW 48 kDa can hydrolyze birchwood and oatspelt xylan. The enzyme had optimum activity at pH 7 and 70°C, with the specific activity of 92.5U/mg. The Xyn10 retained over 90% residual activity at 60°C for 30 min but lost all activity at 80°C over 15 min. Most tested ions showed no or slight inhibition effects on enzyme activity.
Zhang
Guimin
G
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
Mao
Liangwei
L
Zhao
Yueju
Y
Xue
Yanfen
Y
Ma
Yanhe
Y
D001407:Bacillus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004795:Enzyme Stability; D015870:Gene Expression; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors; D014990:Xylans / Q000378:metabolism; D014995:Xylosidases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D004269:DNA, Bacterial; D011994:Recombinant Proteins; D014990:Xylans; D014995:Xylosidases