Introduction

Gene expression is highly regulated by complex protein translation systems. Expression within the eucaryotic cell is especially complicated, involving the mature mRNA, the ribosomal subunits and other protein factors. Furthermore, each component has to interact in a specific function i.e. the small ribosomal subunit has to recognise a start codon, and the large ribosomal subunit has to be recruited before translation can be initiated (Wagner et al.). One such protein is the eucaryotic translation initiation factor 4G (eIF4G), which is needed to recruit the small 40S ribosomal subunit and for scanning along the 5' UTR of the mRNA to the translation start codon. Other regulatory protein which interacts in tandem with the eIF4G includes the 5'-cap-binding protein eIF4E and RNA helicase eIF4A.

In this study, an MIF4G-like protein from the zebrafish was studied for its functional, structural and evolutionary properties. Preliminary information provided by the crystal structure of the protein revealed it to be similar to the middle domain of the eIF4G protein, hence described as "MIF4G-like protein".