title: Protein phylogeny of translation elongation factor EF-1 alpha suggests microsporidians are extremely ancient eukaryotes.
abstract: Partial regions of the mRNA encoding a major part of translation elongation factor 1 alpha (EF-1 alpha) from a mitochondrion-lacking protozoan, Glugea plecoglossi, that belongs to microsporidians, were amplified by polymerase chain reaction (PCR) and their primary structures were analyzed. The deduced amino acid sequence was highly divergent from typical EF-1 alpha's of eukaryotes, although it clearly showed a eukaryotic feature when aligned with homologs of the three primary kingdoms. Maximum likelihood (ML) analyses on the basis of six different stochastic models of amino acid substitutions and a maximum parsimony (MP) analysis consistently suggest that among eukaryotic species being analyzed, G. plecoglossi is likely to represent the earliest offshoot of eukaryotes. Microsporidians might be the extremely ancient eukaryotes which have diverged before an occurrence of mitochondrial symbiosis.
authors.affiliation: Department of Medical Biology, Showa University, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kamaishi
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: F
authors.initials: F
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Murata
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: K
authors.initials: K
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D019143:Evolution, Molecular; D006801:Humans; D016816:Microsporida / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D016054:DNA, Protozoan; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors