Phylogenetic Analysis of Evolutionary Relationships of the Planctomycete Division of the Domain Bacteria Based on Amino Acid Sequences of Elongation Factor Tu |
| |
Authors: | Cheryl Jenkins John A Fuerst |
| |
Institution: | (1) Department of Microbiology, University of Washington, Seattle, WA 98195–7242, USA, US;(2) Department of Microbiology and Parsitology, University of Queensland, Brisbane, Queensland 4072, Australia, AU |
| |
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.
Received: 21 August 2000 / Accepted: 8 January 2001 |
| |
Keywords: | : Planctomycetes — Planctomycetales— Elongation factor — EF-Tu — Domain Bacteria — Long-branch attraction — Deep-branching divisions |
本文献已被 SpringerLink 等数据库收录! |
|