Identification of a protein unique to the genus Plasmodium that contains a WD40 repeat domain and extensive low-complexity sequence.

Abstract

Proteins containing WD40 domains play important roles in the formation of multiprotein complexes. Little is known about WD40 proteins in the malaria parasite. This report contains the initial description of a WD40 protein that is unique to the genus Plasmodium and possibly closely related genera. The N-terminal portion of this protein consists of seven WD40 repeats that are highly conserved in all Plasmodium species. Following the N-terminal region is a central region that is conserved within the major Plasmodium clades, such as parasites of great apes, monkeys, rodents, and birds, but partially conserved across all Plasmodium species. This central region contains extensive low-complexity sequence and is predicted to have a disordered structure. Proteins with disordered structure generally function in molecular interactions. The C-terminal region is semi-conserved across all Plasmodium species and has no notable features. This WD40 repeat protein likely functions in some aspect of parasite biology that is unique to Plasmodium and this uniqueness makes the protein a possible target for therapeutic intervention.