Cloning, expression and nucleotide sequences of two xylanase genes from Paenibacillus sp.

Two genes, xynA and xynB, encoding xylanases from Paenibacillus sp. KCTC 88 48P were cloned and expressed in Escherichia coli, and their nucleotide seq uences were determined. The xylanases of E. coli transformants were release d into the extracellular culture fluid in the absence of xylan. The structu ral gene of xynA, 636 bp, encoded a protein of 212 amino acids, while the x ynB gene consisted of 951 bp open reading frame for a protein of 317 amino acids. The amino acid sequence of the xynA gene showed 83% similarity to th e xylanase of Aeromonas caviae, and belonged to the family 11 glycosyl hydr olases. The deduced amino acid sequence of the xynB gene, however, showed 5 1% similarity to the xylanase of Rhodothermus marinus, and belonged to the family 10 glycosyl hydrolases.