Characterization of a Paenibacillus cell-associated xylanase with high activity on aryl-xylosides: a new subclass of family 10 xylanases.

摘要: The sequence of gene xynB encoding xylanase B from Paenibacillus sp. BP-23 was determined. It revealed an open reading frame 999 nucleotides a protein 38,561 Da. deduced amino acid shows that the N-terminal region enzyme lacks features signal peptide. When xylan-degrading system analysed in zymograms, it not secreted to extracellular medium but instead remained cell-associated, even late stationary-phase cultures. expressed Bacillus subtilis secreting host, also associated with cells. Sequence homology analysis showed belongs family 10 glycosyl hydrolases, exhibiting distinctive high six xylanases this family. homologous enzymes were found be devoid peptide and seem constitute, together B, separate group enzymes. They all have two conserved regions other xylanases, cluster after dendrogram analysis. We propose these constitute new subclass are hydrolyse xylooligosaccharides resulting xylan hydrolysis. Xylanase similar specific activity on aryl-xylosides xylans. This can correlated some, yet identified, trait catalytic plant xylan.