IFIT proteins

[1] So far, four families of this protein have been identified in humans which are IFIT1, IFIT2, IFIT3, and IFIT5 and other variants have been found in different species for example there three mouse members (IFIT1, IFIT2, and IFIT3).

These proteins differ from each other in having different numbers of tetratricopeptide repeats (TPRs) which typically contains 34 amino acids with the consensus sequence [WLF]-X(2)-[LIM]-[GAS]-X (2)-[YLF]-X(8)-[ASE]-X(3)-[FYL]-X(2)-[ASL]-X(4)-[PKE] that adopts a basic helix-turn-helix fold.

It is thought that the gene encoding IFIT proteins in different species has a common ancestry.

[3][4] IFIT proteins are suggested to show anti viral activity in three ways:(see figure)[2] 1.

Experimental data and the three dimensional structure of IFIT1 reveals that the proteins bind to viral PPP RNA in a sequence specific manner.

Widespread gene birth, loss and conversion in vertebrate IFIT genes: A summary table of the IFIT genes of vertebrate species
IFITs, play various roles in blocking virus and host protein translation