Phylogenetic position of kinetoplastid protozoa inferred from the protein phylogenies of elongation factors 1alpha and 2.
Partial regions of the mRNA encoding a major part of translation elongation factor 2 (EF-2) from a kinetoplastid protozoan, Trypanosoma cruzi, were amplified by means of polymerase chain reaction and their primary structures were analyzed. The deduced amino acid sequence was aligned with those of other eukaryotic and archaebacterial EF-2s, and the phylogenetic relationships among eukaryotes were inferred by the maximum likelihood (ML) method. ML analyses of EF-2 phylogeny using six different stochastic models of amino acid substitutions consistently suggested that the phylogenetic position of T. cruzi is likely to be closer to higher eukaryotes than that inferred from the phylogeny of small subunit ribosomal RNA (SrRNA). These results are consistent with those for the elongation factor 1alpha (EF-1alpha) phylogeny. When the EF-1alpha and EF-2 phylogenies were totally evaluated, it became much clearer that the divergence of T. cruzi occurred later than that of a mitochondrion-lacking protozoan, Entamoeba histolytica, although this is not conclusive.
Laboratory of Gene Manipulation, Showa University, Shinagawa-ku, Tokyo.
Y
Y
Nakamura
T
T
Hashimoto
T
T
Kamaishi
J
J
Adachi
F
F
Nakamura
K
K
Okamoto
M
M
Hasegawa
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D004023:Dictyostelium / Q000502:physiology; D019143:Evolution, Molecular; D006801:Humans; D016830:Kinetoplastida / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008322:Mammals; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014349:Trypanosoma cruzi / Q000235:genetics / Q000502:physiology
D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D015800:Protozoan Proteins