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The Deinococcus-Thermus phylum and the effect of rRNA composition on phylogenetic tree constructionThrough comparative analysis of 16S ribosomal RNA sequences, it can be shown that two seemingly dissimilar types of eubacteria Deinococcus and the ubiquitous hot spring organism Thermus are distantly but specifically related to one another. This confirms an earlier report based upon 16S rRNA oligonucleotide cataloging studies (Hensel et al., 1986). Their two lineages form a distinctive grouping within the eubacteria that deserved the taxonomic status of a phylum. The (partial) sequence of T. aquaticus rRNA appears relatively close to those of other thermophilic eubacteria. e.g. Thermotoga maritima and Thermomicrobium roseum. However, this closeness does not reflect a true evolutionary closeness; rather it is due to a "thermophilic convergence", the result of unusually high G+C composition in the rRNAs of thermophilic bacteria. Unless such compositional biases are taken into account, the branching order and root of phylogenetic trees can be incorrectly inferred.
Document ID
20040089061
Document Type
Reprint (Version printed in journal)
Authors
Weisburg, W. G. (University of Illinois Urbana 61801, United States)
Giovannoni, S. J.
Woese, C. R.
Date Acquired
August 21, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Systematic and applied microbiology
Volume: 11
ISSN: 0723-2020
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: BSR87-05352
CONTRACT_GRANT: GM 34527
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Exobiology