Plasmodium, theApicomplexaoutlier when it comes to protein synthesis

Abstract

ABSTRACTPlasmodiumis an obligate intracellular parasite that makes numerous interactions with different hosts during its elaborate life cycle. This is also the case for other parasites that belong to the same phylumApicomplexa. In this study, we identified bioinformatically the components of the multi-synthetase complexes (MSC) of severalApicomplexaparasites. By using AlphaFold2 modeling to compare their assembly, it appears that none of these MSCs resemble those identified inPlasmodium. In particular, the discrepancies between the core components ofPlasmodiumcomplexes, tRip and its homologs indicate that tRip-dependent exogenous tRNA import is not conserved in the otherApicomplexaparasites. Based on this observation, we looked for obvious differences that could explain this singularity inPlasmodium. The content of tRNA genes and amino acid usage in the different genomes highlighted the originality ofPlasmodiatranslation. This is evident with respect to asparagine amino acid, which is highly used in thePlasmodiumproteomes, and the scarcity of tRNAAsnrequired for protein synthesis, regardless of long homorepeats or AT content of the genomes.