Rose Jayson J A, Johnson Matthew D, Reyhani Milad, Batinovic Steven, Seviour Robert J, Ghosal Debnath, Petrovski Steve
Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Bundoora, VIC, Australia.
La Trobe Institute for Molecular Sciences (LIMS), La Trobe University, Bundoora, VIC, Australia.
Nat Commun. 2025 Mar 5;16(1):2202. doi: 10.1038/s41467-025-56933-4.
The obligate necrotrophic parasite, Candidatus Mycosynbacter amalyticus, a member of the Patescibacteria has been isolated from wastewater. Subsequent efforts have been directed toward unravelling its biological lifecycle and attachment mechanism facilitating infection and subsequent lysis of its Actinobacterial host, Gordonia amarae. Here, using electron cryo-tomography (CryoET), we reveal the molecular anatomy of parasitic Mycosynbacter amalyticus cells, uncovering an unusual infection process. Through laboratory-based evolution experiments, we generated eleven slow-growing independent spontaneous Gordonia amarae resistant mutants. Mycolic acids (MA) are key components of the outer cellular envelope of G. amarae and other Actinobacteria, with MA being the physical attribute implicated in G. amarae associated wastewater foaming. CryoET and genome sequencing exposed absence of intact MA and an associated suite of mutations predominantly occurring within the pks13 and pptT genes of the MA biosynthetic pathway. Our findings suggest that MA structural integrity is critical for attachment of Ca. Mycosynbacter amalyticus to its host.
专性坏死营养型寄生虫“暂定分支杆菌属分析菌（Candidatus Mycosynbacter amalyticus）”是Patescibacteria的成员，已从废水中分离出来。随后的研究致力于揭示其生物生命周期以及促进其感染放线菌宿主戈氏链霉菌（Gordonia amarae）并使其随后裂解的附着机制。在此，我们使用电子冷冻断层扫描（CryoET）揭示了寄生性分支杆菌属分析菌细胞的分子结构，发现了一个不同寻常的感染过程。通过基于实验室的进化实验，我们获得了11个生长缓慢的独立自发的戈氏链霉菌抗性突变体。分枝菌酸（MA）是戈氏链霉菌和其他放线菌细胞外被膜的关键成分，MA是与戈氏链霉菌相关的废水泡沫形成有关的物理属性。CryoET和基因组测序表明，完整的MA不存在，并且一组相关突变主要发生在MA生物合成途径的pks13和pptT基因内。我们的研究结果表明，MA的结构完整性对于暂定分支杆菌属分析菌附着于其宿主至关重要。
