Florence Ng’ong’a

Trypanosomes are protozoans causing African trypanosomiasis, a neglected tropical disease in Africa affecting humans and animals. Control methods have focused on the use of drugs which have adverse effects and vector control methods which have proved to be ecologically unsustainable. However, no conventional vaccine exists due to antigenic variation. In trypanosomes, peptidases are widely implicated as virulence factors thus could be targeted in the development in new therapeutic agents. This study predicts the presence of three putative tricorn protease interacting factor 3 genes in Trypanosoma brucei brucei, two of which appear to represent gene duplication. The genes were identified through a combination of PSI-BLAST, orthology clustering and structure predictions. Motif conservation was predicted through MEME suite and STRING database was used to predict protein–protein interactions. Both sequence and structural prediction showed considerable conservation among the homologues. The overall predicted structures of the putative Trf 3 homologues in T. b. brucei had four domains; N-terminal domain I predominantly composed of β-sheets, catalytic domain II composed of mixed α/β structure, saddle-like domain III composed of β-sheets and C-terminal domain IV composed of α-helices, organized into a super helix. The active site with the zinc-binding motif ({HEXXH (18X) E}), the GXMEN motif specific for M1 family as well as the N-terminal substrate anchoring, glutamate and the proton acceptor, tyrosine were conserved. The STRING network predicted interaction between the putative Trf 3 homologues with proteasomal core complex through polyubiquitin suggesting that they could be proteasomal components.