Trypanosomatid DRBD9s are likely to be eIF4B orthologues

Initiation of protein translation is one of the key steps in protein synthesis carried out by translation initiation factors in conjunction with ribosomes. The roles and mechanisms of these initiation factors in prokaryotic and eukaryotic protein synthesis are well understood. However, they are only beginning to be understood in trypanosomatids. Trypanosomatid translation initiation factors have differences with eukaryotic translation initiation factors, e.g., they have six keIF4Es and five keIF4Gs with significant novelty in their structure–function relationships. The trypanosomatid keIF4Es and keIF4Gs are the most well studied initiation factors. However, a trypanosomatid orthologue of the eukaryotic initiation factor 4B (eIF4B) has not been previously reported. In this report, using bioinformatics tools and homology modelling/structure prediction studies, we identified trypanosomatid double RNA binding domain protein 9s (DRBD9s) as likely orthologues of eIF4Bs.