title: Universally conserved translation initiation factors.
abstract: The process by which translation is initiated has long been considered similar in Bacteria and Eukarya but accomplished by a different unrelated set of factors in the two cases. This not only implies separate evolutionary histories for the two but also implies that at the universal ancestor stage, a translation initiation mechanism either did not exist or was of a different nature than the extant processes. We demonstrate herein that (i) the "analogous" translation initiation factors IF-1 and eIF-1A are actually related in sequence, (ii) the "eukaryotic" translation factor SUI1 is universal in distribution, and (iii) the eukaryotic/archaeal translation factor eIF-5A is homologous to the bacterial translation factor EF-P. Thus, the rudiments of translation initiation would seem to have been present in the universal ancestor stage. However, significant development and refinement subsequently occurred independently on both the bacterial lineage and on the archaeal/eukaryotic line.
authors.affiliation: Department of Microbiology, University of Illinois at Urbana-Champaign, B103 Chemistry and Life Sciences, MC 110, 407 South Goodwin, Urbana, IL 61801, USA. nikos@darwin.life.uiuc.edu
authors.forename: N C
authors.initials: NC
authors.lastname: Kyrpides
authors.forename: C R
authors.initials: CR
authors.lastname: Woese
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001105:Archaea; D017124:Conserved Sequence; D015977:Eukaryotic Initiation Factor-1 / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors / Q000737:chemistry; D010448:Peptide Initiation Factors / Q000737:chemistry*; D016601:RNA-Binding Proteins; D016415:Sequence Alignment; D000097574:Eukaryotic Translation Initiation Factor 5A
chemical_list: D015977:Eukaryotic Initiation Factor-1; D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins; D000097574:Eukaryotic Translation Initiation Factor 5A; C026022:eukaryotic peptide initiation factor-1A; C020746:factor EF-P