title: Phylogenetic analysis of evolutionary relationships of the planctomycete division of the domain bacteria based on amino acid sequences of elongation factor Tu.
abstract: Sequences from the tuf gene coding for the elongation factor EF-Tu were amplified and sequenced from the genomic DNA of Pirellula marina and Isosphaera pallida, two species of bacteria within the order Planctomycetales. A near-complete (1140-bp) sequence was obtained from Pi. marina and a partial (759-bp) sequence was obtained for I. pallida. Alignment of the deduced Pi. marina EF-Tu amino acid sequence against reference sequences demonstrated the presence of a unique 11-amino acid sequence motif not present in any other division of the domain Bacteria. Pi. marina shared the highest percentage amino acid sequence identity with I. pallida but showed only a low percentage identity with other members of the domain Bacteria. This is consistent with the concept of the planctomycetes as a unique division of the Bacteria. Neither primary sequence comparison of EF-Tu nor phylogenetic analysis supports any close relationship between planctomycetes and the chlamydiae, which has previously been postulated on the basis of 16S rRNA. Phylogenetic analysis of aligned EF-Tu amino acid sequences performed using distance, maximum-parsimony, and maximum-likelihood approaches yielded contradictory results with respect to the position of planctomycetes relative to other bacteria. It is hypothesized that long-branch attraction effects due to unequal evolutionary rates and mutational saturation effects may account for some of the contradictions.
authors.affiliation: Department of Microbiology, University of Washington, Seattle, WA 98195-7242, USA.
authors.forename: C
authors.initials: C
authors.lastname: Jenkins
authors.forename: J A
authors.initials: JA
authors.lastname: Fuerst
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D002689:Chlamydia / Q000737:chemistry / Q000145:classification / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D019143:Evolution, Molecular; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010444:Peptide Elongation Factor Tu / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D010444:Peptide Elongation Factor Tu