Phylogeny of β-xylanases from Planctomycetes

Here, we present the results of a computational analysis of a group of hypothetical GH10 endo-β-xylanases from the Planctomycetes, a bacterial phylum with poorly characterized functional capabilities. These proteins are encoded in all analyzed genomes of heterotrophic Planctomycetes and form a phylogenetically distinct and tight cluster. In addition, we determined nucleotide sequences for endo-β-xylanase genes from five strains of Isosphaera-Singulisphaera group of the Planctomycetes. The trees constructed for the 16S rRNA genes and the inferred amino acid sequences of endo-β-xylanases were highly congruent, thus suggesting the vertical transfer of endo-β-xylanase genes and their functional importance in Planctomycetes.