Translation initiation factor IF-1 (IPR004368)

Short name: TIF_IF1

Overlapping homologous superfamilies

Family relationships



This family consists of translation initiation factor IF-1 as found in bacteria and chloroplasts. This protein, about 70 residues in length, consists largely of an S1 RNA binding domain (IPR003029) [PMID: 9008164].

Translation initiation includes a number of interrelated steps preceding the formation of the first peptide bond. In Escherichia coli, the initiation mechanism requires, in addition to mRNA, fMet-tRNA, and ribosomal subunits, the presence of three additional proteins (initiation factors IF1, IF2, and IF3) and at least one GTP molecule. The three initiation factors influence both the kinetics and the stability of ternary complex formation. IF1 is the smallest of the three factors. IF1 enhances the rate of 70S ribosome subunit association and dissociation and the interaction of 30S ribosomal subunit with IF2 and IF3. It stimulates 30S complex formation. In addition, by binding to the A-site of the 30S ribosomal subunit, IF1 may contribute to the fidelity of the selection of the initiation site of the mRNA [PMID: 9135158, PMID: 16938378, PMID: 11228145, PMID: 10860719, PMID: 14600024].

GO terms

Biological Process

GO:0006413 translational initiation

Molecular Function

GO:0003743 translation initiation factor activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.