Phylogenetic depth of Thermotoga maritima inferred from analysis of the fus gene : amino acid sequence of elongation factor G and organization of the Thermotoga str operon

• Published in: Journal of molecular evolution 1991-08, Vol.33 (2), p.142-151
• Main Authors: TIBONI, O, CANTONI, R, CRETI, R, CAMMARANO, P, SANANGELANTONI, A. M
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Base Sequence; Biological and medical sciences; Biological evolution; Cloning, Molecular; Codon; DNA; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetics of eukaryotes. Biological and molecular evolution; Gram-Negative Anaerobic Bacteria - classification; Gram-Negative Anaerobic Bacteria - genetics; Molecular Sequence Data; Operon; Peptide Elongation Factor G; Peptide Elongation Factors - genetics; Phylogeny; Restriction Mapping; Sequence Alignment; Thermotoga maritima
• ISSN: 0022-2844; 1432-1432
• DOI: 10.1007/BF02193628

The gene (fus) coding for elongation factor G (EF-G) of the extremely thermophilic eubacterium Thermotoga maritima was identified and sequenced. The EF-G coding sequence (2046 bp) was found to lie in an operon-like structure between the ribosomal protein S7 gene (rpsG) and the elongation factor Tu (EF-Tu) gene (tuf). The rpsG, fus, and tuf genes follow each other immediately in that order, which corresponds to the order of the homologous genes in the str operon of Escherichia coli. The derived amino acid sequence of the EF-G protein (682 residues) was aligned with the homologous sequences of other eubacteria, eukaryotes (hamster), and archaebacteria (Methanococcus vannielii). Unrooted phylogenetic dendrograms, obtained both from the amino acid and the nucleotide sequence alignments, using a variety of methods, lend further support to the notion that the (present) root of the (eu)bacterial tree lies between Thermotoga and the other bacterial lineages.