Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67084 Strasbourg, France.
Biomolecules. 2023 Dec 29;14(1):46. doi: 10.3390/biom14010046.
is an obligate intracellular parasite that has numerous interactions with different hosts during its elaborate life cycle. This is also the case for the other parasites belonging to the same phylum . In this study, we bioinformatically identified the components of the multi-synthetase complexes (MSCs) of several parasites and modelled their assembly using AlphaFold2. It appears that none of these MSCs resemble the two MSCs that we have identified and characterized in . Indeed, tRip, the central protein involved in the association of the two MSCs is different from its homologues, suggesting also that the tRip-dependent import of exogenous tRNAs is not conserved in other apicomplexan parasites. Based on this observation, we searched for obvious differences that could explain the singularity of protein synthesis by comparing tRNA genes and amino acid usage in the different genomes. We noted a contradiction between the large number of asparagine residues used in proteomes and the single gene encoding the tRNA that inserts them into proteins. This observation remains true for all the strains studied, even those that do not contain long asparagine homorepeats.
是一种专性细胞内寄生虫，在其复杂的生命周期中与不同的宿主有许多相互作用。属于同一门的其他寄生虫也是如此。在这项研究中，我们通过生物信息学方法鉴定了几种寄生虫的多合成酶复合物（MSCs）的组成部分，并使用 AlphaFold2 对其组装进行了建模。似乎这些 MSC 都不像我们在中鉴定和表征的两种 MSC。事实上，参与两种 MSC 结合的中心蛋白 tRip 与其同源物不同，这也表明外源 tRNA 的 tRip 依赖性导入在其他顶复门寄生虫中并不保守。基于这一观察结果，我们通过比较不同基因组中的 tRNA 基因和氨基酸使用情况，寻找可能解释的明显差异，从而解释蛋白质合成的独特性。我们注意到，在中蛋白组中使用的大量天冬酰胺残基与插入这些残基的 tRNA 的单个基因之间存在矛盾。即使对于不含有长天冬酰胺同源重复的所有株系，这种观察结果仍然成立。
