The
xynA gene encoding a xylanase from the recently isolated
Bacillus sp. strain BP-7 has been cloned and expressed in
Escherichia coli. Recombinant xylanase A showed high activity on xylans from hardwoods and cereals, and exhibited maximum activity at pH 6 and 60°C. The enzyme remained stable after incubation at 50°C and pH 7 for 3 h, and it was strongly inhibited by Mn
2+, Fe
3+, Pb
2+, and Hg
2+. Analysis of xylanase A in zymograms showed an apparent molecular size of 24 kDa and a pI of above 9. The amino acid sequence of xylanase A, as deduced from
xynA gene, shows homology to alkaline pI-low molecular weight xylanases of family 11 such as XynA from
Bacillus subtilis. Analysis of codon usage in
xynA from
Bacillus sp. BP-7 shows that the G+C content at the first and second codon positions is notably different from the mean values found for glycosyl hydrolase genes from
Bacillus subtilis.