Homo_sapiensFamily: IF-2 Number of Genes: 2
Ensembl IDSymbolEntrez IDRBD RBPome PRIExpresion PathwayPhenotype ParalogOrthologGO



IF-2 is a translation initiator in each of the three main phylogenetic domains (Eukaryotes [1] Bacteria [2] and Archaea [3]). IF2 interacts with formylmethionine-tRNA, GTP, IF1, IF3 and both ribosomal subunits [2]. Through these interactions, IF2 promotes the binding of the initiator tRNA to the A site in the smaller ribosomal subunit and catalyses the hydrolysis of GTP following initiation-complex formation [2].


Initiation factor 2 (IF-2) is one of the three factors required for the initiation of protein biosynthesis in bacteria [PUBMED:15755955]. IF-2 promotes the GTP-dependent binding of the initiator tRNA to the small subunit of the ribosome. IF-2 is a protein of about 70 to 95 kDa that contains a central GTP-binding domain flanked by a highly variable N-terminal domain and a more conserved C-terminal domain. Some members of this group undergo protein self splicing that involves a post-translational excision of the intein followed by peptide ligation.


  1. Aury JM, Jaillon O, Duret L, Noel B, Jubin C, Porcel BM, Segurens B, Daubin V, Anthouard V, Aiach N, Arnaiz O, Billaut A, Beisson J, Blanc I, Bouhouche K, Camara F, Duharcourt S, Guigo R, Gogendeau D, Katinka M, Keller AM, Kissmehl R, Klotz C, Koll F, Le , Nature. 2006;444:171-178.: Global trends of whole-genome duplications revealed by the ciliate Paramecium tetraurelia. PUBMED:17086204 EPMC:17086204 .

  2. Hedegaard J, Hauge M, Fage-Larsen J, Mortensen KK, Kilian M, Sperling-Petersen HU, Poulsen K;, Microbiology. 2000;146:1661-1670.: Investigation of the translation-initiation factor IF2 gene, infB, as a tool to study the population structure of Streptococcus agalactiae. PUBMED:10878130 EPMC:10878130 .

  3. Falb M, Pfeiffer F, Palm P, Rodewald K, Hickmann V, Tittor J, Oesterhelt D;, Genome Res. 2005;15:1336-1343.: Living with two extremes: conclusions from the genome sequence of Natronomonas pharaonis. PUBMED:16169924 EPMC:16169924.