Translation initiation factor 2, beta subunit (IPR004458)

Short name: TIF2_bsu_arc

Overlapping homologous superfamilies

Family relationships



Archaeal transcription initiation factor 2 is, like its eukaryotic homologue, a heterotrimeric protein with alpha, beta and gamma subunits [PMID: 11980477]. It is thought play an essential role in the recognition of the correct codon for the start of translation, similar to the role of eukaryotic transcription initiation factor. The eukaryotic factor forms a ternary complex with the methionine initiator tRNA and GTP, which binds to the 40S ribosomal subunit as part of the 43S preinitiation complex [PMID: 11416183]. The beta and gamma subunits are responsible for recruiting the initiator tRNA and GTP, while the alpha subunit is involved in the regulation of the translation initiation process. The beta subunit has also been shown to interact with other transcription factors. All three subunits of the archaeal and eukaryotic factors are well conserved among the diverse species of eukaryotes and archaea, but do not occur in prokaryotes.

The archaeal beta subunit has an unfolded N-terminal domain, a mixed alpha/beta core domain and a C-terminal zinc finger [PMID: 14978306]. The N-terminal region is thought to interact with the gamma subunit, while the central and C-terminal domains are thought to provide RNA-binding sites.

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.