The phyla Planctomycetes, Verrucomicrobia, Chlamydiae, and Lentisphaerae, Poribacteria and OP3 comprise bacteria that share a common ancestor but show highly diverse biological and ecological features. Together they constitute the PVC superphylum. Using large scale comparative genome sequence analysis we identified a protein uniquely shared among all known members of the PVC superphylum. We provide evidence that this signature protein is expressed by representative members of the PVC superphylum. Its predicted structure, physicochemical characteristics, overexpression in E. coli and gel retardation assays with purified signature protein suggest a housekeeping function with unspecific DNA/RNA binding activity. P... More
The phyla Planctomycetes, Verrucomicrobia, Chlamydiae, and Lentisphaerae, Poribacteria and OP3 comprise bacteria that share a common ancestor but show highly diverse biological and ecological features. Together they constitute the PVC superphylum. Using large scale comparative genome sequence analysis we identified a protein uniquely shared among all known members of the PVC superphylum. We provide evidence that this signature protein is expressed by representative members of the PVC superphylum. Its predicted structure, physicochemical characteristics, overexpression in E. coli and gel retardation assays with purified signature protein suggest a housekeeping function with unspecific DNA/RNA binding activity. Phylogenetic analysis demonstrated that the signature protein is a suitable phylogenetic marker for members of the PVC superphylum, and the screening of published metagenome data indicated the existence of additional PVC members. This study provides further evidence for a common evolutionary history of the PVC superphylum and presents a unique case in which a single protein serves as an evolutionary link between otherwise highly diverse members of major bacterial groups.
