Discussion

A Twisted Protein

Figure 2: MIF4G, viewed along the cylindrical axes of the alpha helices. (Marcotrigiano et al.) Each colour represents an alpha helix hairpin. Black line indicates a groove between two hairpins.

The above results demonstrate a parallel, highly similar structure of eIF4G-like protein to human MIF4G (PDB: 1hu3). While there is a lack of conclusive studies and evidence on our protein of interest, the established protein MIF4G can be utilised as a model to formulate predictions on its structure. According to Wagner et al., MIF4G contains five helical hairpins oriented in a right-handed solenoid, and is similar to the HEAT [Huntingtin, elongation factor 3, a subunit of protein phosphatase 2A (PP2A), and target of rapamycin] domain (wagner et al). The overall protein resembles a crescent, with its superhelical axis perpendicular to the cylindrical axes of the alpha helices (marcotrigiano et al.). The helical hairpins are stacked one on top of the other to confer the protein its overall crescent shape.

MIF4G binds to eIF4A, an RNA helicase, and RNA, hence rendering its role in regulating cell translation. A protease-resistant region identified by proteolysis and mass spectrometry is speculated to be the binding site for eIF4A (marcotrigiano et al.).