Novel structural features of xylanase A1 from Paenibacillus sp. JDR-2.
The Gram-positive bacterium Paenibacillus sp. JDR-2 (PbJDR2) has been shown to
have novel properties in the utilization of the abundant but chemically complex
hemicellulosic sugar glucuronoxylan. Xylanase A1 of PbJDR2 (PbXynA1) has been
implicated in an efficient process in which extracellular depolymerization of
this polysaccharide is coupled to assimilation and intracellular metabolism.
PbXynA1is a 154kDa cell wall anchored multimodular glycosyl hydrolase family 10
(GH10) xylanase. In this work, the 38kDa catalytic module of PbXynA1 has been
structurally characterized revealing several new features not previously
observed in structures of GH10 xylanases. These features are thought to
facilitate hydrolysis of highly substituted, chemically complex xylans that may
be the form found in close proximity to the cell wall of PbJDR2, an organism
shown to have a preference for growth on polymeric glucuronoxylan.