PHYLOGENY BASED ON ELONGATION-FACTOR TU REFLECTS THE PHENOTYPIC FEATURES OF MYCOPLASMAS BETTER THAN THAT BASED ON 16S RIBOSOMAL-RNA

A universal phylogenetic tree of organisms from all kingdoms was const ructed by the use of elongation factor Tu (EF-Tu) as the marker molecu le. As in the 16S ribosomal RNA (16S rRNA)-based phylogeny, the EF-Tu tree divides eukaryotes, archaebacteria and prokaryotes into three mai n branches. Furthermore, the EF-Tu-based tree shows, in contrast to th e 16S rRNA tree, some interesting evolutionary relationships between m ycoplasmas, better reflecting phenotypic features of these organisms.