IFIT1
Domain
RNA recognition is mediated by a convoluted intramolecular fold of the TPR repeats (TPR eddy), which scaffolds unique additional helices that form an RNA binding cleft.
Function
Interferon-induced antiviral RNA-binding protein that specifically binds single-stranded RNA bearing a 5'-triphosphate group (PPP-RNA), thereby acting as a sensor of viral single-stranded RNAs and inhibiting expression of viral messenger RNAs. Single-stranded PPP-RNAs, which lack 2'-O-methylation of the 5' cap and bear a 5'-triphosphate group instead, are specific from viruses, providing a molecular signature to distinguish between self and non-self mRNAs by the host during viral infection. Directly binds PPP-RNA in a non-sequence-specific manner. Viruses evolved several ways to evade this restriction system such as encoding their own 2'-O-methylase for their mRNAs or by stealing host cap containing the 2'-O-methylation (cap snatching mechanism). Exhibits antiviral activity against several viruses including human papilloma and hepatitis C viruses.
Post-translational modifications
Phosphorylated.
ISGylated.
Sequence Similarities
Belongs to the IFIT family.
Cellular localization
- Cytoplasm
Alternative names
G10P1, IFI56, IFNAI1, ISG56, IFIT1, Interferon-induced protein with tetratricopeptide repeats 1, IFIT-1, Interferon-induced 56 kDa protein, IFI-56K, P56