EIF1AX

Eukaryotic translation initiation factor 1A, X-chromosomal (eIF1A) is a protein that in humans is encoded by the EIF1AX gene. This gene encodes an essential eukaryotic translation initiation factor. The protein is a component of the 43S pre-initiation complex (PIC), which mediates the recruitment of the small 40S ribosomal subunit to the 5' cap of messenger RNAs.

Function

See also: Eukaryotic_translation § Cap-dependent_initiation

eIF1A is an important part of the translation intiation mechanism. It is located at the A-site of the small ribosomal subunit. During translation initiation, the 43S pre-initiation complex scans along the mRNA in search of a start codon. eIF1A's N-terminal tail interacts with the initiator tRNA and the start codon by extending into the P-site, thereby increasing the fidelity of start codon selection. After the start codon has been selected and eIF1, eIF2, and eIF5 have left the pre-initiation complex, eIF5B is recruited to continue the initiation process. Here, eIF1A interacts with eIF5B such that eIF5B is remodeled into a conformation that allows joining of the large ribosomal subunit. After the joining of the subunit, it is the dissociation of eIF1A that permits eIF5B to rearrange again, placing the tRNA in its final position.

Clinical significance

Mutations in this gene have been recurrently seen associated to cases of uveal melanoma with disomy 3. eIF1A is mutated in thyroid cancers.

Interactions

EIF1AX has been shown to interact with IPO13.

See also

• Eukaryotic initiation factors

External links

• Overview of all the structural information available in the PDB for UniProt: P47813 (Eukaryotic translation initiation factor 1A, X-chromosoma) at the PDBe-KB.