Evolutionary relationship between Halobacterium cutirubrum and eukaryotes determined by use of aminoacyl-tRNA synthetases as phylogenetic probes

Abstract

The cross-species reactivities between tRNA and aminoacyl-tRNA synthetases were employed as a basis to estimate the relatedness of various prokaryotes to the eukaryotes. The tRNA of H. cutirubrum, unlike that of other prokaryotes tested, including Agrobacterium tumefaciens, Arthrobacter luteus, Bacillus subtilis, B. stearothermophilus, Escherichia coli, Micrococcus luteus, Myxococcus xanthus, Rhodopseudomonas sphaeroides and Thermus aquaticus, shared with yeast, rat liver and wheat germ tRNA a distinct preference for aminoacylation by eukaryotic synthetases from yeast as opposed to prokaryotic synthetases from either E. coli or R. spheroides. Phylogenetically, H. cutirubrum may be more closely related to the eukaryotes than to the eubacteria.