Gene cloning, sequencing, and biochemical characterization of endoxylanase from Thermoanaerobacterium saccharolyticum B6A-RI.
The gene encoding endoxylanase (xynA) from Thermoanaerobacterium saccharolyticum B6A-RI was cloned and expressed in Escherichia coli. A putative 33-amino-acid signal peptide, which corresponded to the N-terminal amino acids, was encoded by xynA. An open reading frame of 3,471 bp, corresponding to 1,157 amino acid residues, was found, giving the xynA gene product a molecular mass of 130 kDa. xynA from T. saccharolyticum B6A-RI had strong similarity to genes from family F beta-glycanases. The temperature and pH optimum for the activity of the cloned endoxylanase were 70 degrees C and 5.5, respectively. The cloned endoxylanase A was stable at 75 degrees C for 60 min and displayed a specific activity of 227.4 U/mg of protein on oat spelt xylan. The cloned xylanase was an endo-acting enzyme.
Lee
Y E
YE
Department of Microbiology and Public Health, Michigan State University, East Lansing 48824.
Lowe
S E
SE
Zeikus
J G
JG
D001421:Bacteria, Anaerobic / Q000201:enzymology* / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D043364:Endo-1,4-beta Xylanases; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D021382:Protein Sorting Signals / Q000235:genetics; D014990:Xylans
D004269:DNA, Bacterial; D021382:Protein Sorting Signals; D014990:Xylans; D006026:Glycoside Hydrolases; D043364:Endo-1,4-beta Xylanases