β-Fructosidases of Planctomycetes: Structure and Evolution

Abstract Planctomycetes are widespread and abundant in many natural ecosystems. Their large genomes encode a vast assortment of glycoside hydrolases, resulting in the high glycolytic potential of these bacteria. This work is devoted to the study of genetic diversity of potential β-fructosidases in planctomycetes. Analysis of genomic sequences revealed a key role of members of one subfamily (32b) within the GH32 family of glycoside hydrolases in fructan utilization. Phylogenetic analysis demonstrated multiple lateral transfers of the corresponding genes both among planctomycetes and into bacteria of several other phyla. The domain architecture of planctomycetal β-fructosidases is discussed, including the presence or absence of a substrate-binding domain from the CBM38 family.