Paulus Anja, Ahrens Frederik, Schraut Annika, Hofmann Hannah, Schiller Tim, Sura Thomas, Becher Dörte, Uebe René
Department of Microbiology, University of Bayreuth, Bayreuth, Germany.
Microbial Proteomics, Institute of Microbiology, University of Greifswald, Greifswald, Germany.
Nat Commun. 2024 Dec 9;15(1):10657. doi: 10.1038/s41467-024-55121-0.
Organelle-specific protein translocation systems are essential for organelle biogenesis and maintenance in eukaryotes but thought to be absent from prokaryotic organelles. Here, we demonstrate that MamF-like proteins are crucial for the formation and functionality of bacterial magnetosome organelles. Deletion of mamF-like genes in the Alphaproteobacterium Magnetospirillum gryphiswaldense results in severe defects in organelle positioning, biomineralization, and magnetic navigation. These phenotypic defects result from the disrupted targeting of a subset of magnetosomal proteins that contain C-terminal glycine-rich integral membrane domains. Phylogenetic analyses reveal an ancient evolutionary link between MamF-like proteins and plastidial Tic20. Our findings redefine the molecular roles of MamF-like proteins and suggest that organelle-specific protein targeting systems also play a role in bacterial organelle formation.
细胞器特异性蛋白质转运系统对于真核生物细胞器的生物发生和维持至关重要，但原核细胞器中被认为不存在该系统。在此，我们证明MamF样蛋白对于细菌磁小体细胞器的形成和功能至关重要。在α-变形菌磁螺菌中缺失MamF样基因会导致细胞器定位、生物矿化和磁导航方面的严重缺陷。这些表型缺陷是由于包含C端富含甘氨酸的整合膜结构域的一部分磁小体蛋白的靶向作用被破坏所致。系统发育分析揭示了MamF样蛋白与质体Tic20之间古老的进化联系。我们的研究结果重新定义了MamF样蛋白的分子作用，并表明细胞器特异性蛋白质靶向系统在细菌细胞器形成中也发挥作用。
