Remarkable Conservation of Translation Initiation Factors: IF1/eIF1A and IF2/eIF5B are Universally Distributed Phylogenetic Markers

• Published in: IUBMB life 2001-05, Vol.51 (5), p.321-327
• Main Authors: Sørensen, Hans Peter, Hedegaard, Jakob, Sperling‐Petersen, Hans Uffe, Mortensen, Kim Kusk
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Biosynthesis; Components; Conserved Sequence; Escherichia coli - genetics; Eukaryotic Initiation Factor-1 - genetics; Eukaryotic Initiation Factor-5; Evolution; Evolution, Molecular; Genetic Markers; Genome; Geobacillus stearothermophilus - genetics; Haemophilus - genetics; Humans; If1/EIF1A; If2/EIF5B; Initiation; Markers; Methanobacterium - genetics; Molecular; Molecular Sequence Data; Peptide Initiation Factors - genetics; Phylogeny; Protein; Ribosomal; Sequence Homology, Amino Acid; Translation; Universal
• ISSN: 1521-6543; 1521-6551
• DOI: 10.1080/152165401317190842

Initiation of protein biosynthesis is an essential process occurring in cells throughout the three phylogenetic domains, Bacteria, Archaea, and Eucarya. IF1/eIF1A and IF2/eIF5B, two conserved translation initiation factors are involved in this important step of protein biosynthesis. The essentiality, universal distribution, conservation, and interspecies functional homology of both factors are a unique combination of properties ideal for molecular phylogenetic studies as demonstrated by the extensively compared SSU rRNAs. Here, we assess the use of IF1/eIF1A and IF2/eIF5B in universal and partial phylogenetic studies by comparison of sequence information from species within all three phylogenetic domains and among closely related strains of Haemophilus parainfluenzae . We conclude that the amino acid sequence of IF1/eIF1A‐IF2/eIF5B is a universal phylogenetic marker and that the nucleotide sequence of the IF2/eIF5B G‐domain is more credible than SSU rRNA for the construction of partial phylogenies among closely related species and strains. Because of these two application levels, IF1/eIF1AIF2/eIF5B is a phylogenetic “dual level” marker.