Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany.
Institute of Biology/Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany.
mBio. 2024 Oct 16;15(10):e0149224. doi: 10.1128/mbio.01492-24. Epub 2024 Sep 9.
The cell wall of monoderm bacteria consists of peptidoglycan and glycopolymers in roughly equal proportions and is crucial for cellular integrity, cell shape, and bacterial vitality. Despite the immense value of in biotechnology and medicine as antibiotic producers, we know very little about their cell wall biogenesis, composition, and functions. Here, we have identified the LCP-LytR_C domain protein CglA (Vnz_13690) as a key glycopolymer ligase which specifically localizes in zones of cell wall biosynthesis in . Reduced amount of glycopolymers in the mutant results in enlarged vegetative hyphae and failures in FtsZ-rings formation and positioning. Consequently, division septa are misplaced leading to the formation of aberrant cell compartments, misshaped spores, and reduced cell vitality. In addition, we report our discovery that c-di-AMP signaling and decoration of the cell wall with glycopolymers are physiologically linked in since the deletion of restores growth of the mutant at high salt. Altogether, we have identified and characterized CglA as a novel component of cell wall biogenesis in , which is required for cell shape maintenance and cellular vitality in filamentous, multicellular bacteria.IMPORTANCE are our key producers of antibitiotics and other bioactive molecules and are, therefore, of high value for medicine and biotechnology. They proliferate by apical extension and branching of hyphae and undergo complex cell differentiation from filaments to spores during their life cycle. For both, growth and sporulation, coordinated cell wall biogenesis is crucial. However, our knowledge about cell wall biosynthesis, functions, and architecture in and in other Actinomycetota is still very limited. Here, we identify CglA as the key enzyme needed for the attachment of glycopolymers to the cell wall of . We demonstrate that defects in the cell wall glycopolymer content result in loss of cell shape in these filamentous bacteria and show that division-competent FtsZ-rings cannot assemble properly and fail to be positioned correctly. As a consequence, cell septa placement is disturbed leading to the formation of misshaped spores with reduced viability.
单壁菌的细胞壁由肽聚糖和糖聚合物大致等量组成，对于细胞完整性、细胞形状和细菌活力至关重要。尽管作为抗生素生产者，在生物技术和医学中具有巨大的价值，但我们对其细胞壁生物发生、组成和功能知之甚少。在这里，我们已经确定 LCP-LytR_C 结构域蛋白 CglA（Vnz_13690）为一种关键的糖聚合物连接酶，它特异性地定位于 中的细胞壁生物合成区域。突变体中糖聚合物的减少导致营养菌丝伸长，FtsZ-环的形成和定位失败。结果，分裂隔膜位置不当导致异常细胞隔室的形成、畸形孢子的形成和细胞活力降低。此外，我们报告了我们的发现，即在 中 c-di-AMP 信号和细胞壁糖聚合物的修饰在生理上是相关的，因为缺失 恢复了高盐条件下 突变体的生长。总之，我们已经确定并表征了 CglA 作为 的细胞壁生物发生的一个新组件，它对于丝状多细胞细菌的细胞形状维持和细胞活力是必需的。
重要的是，它们是我们抗生素和其他生物活性分子的关键生产者，因此对医学和生物技术具有很高的价值。它们通过菌丝的顶端延伸和分支进行增殖，并在其生命周期中经历从菌丝到孢子的复杂细胞分化。对于生长和孢子形成，协调的细胞壁生物发生是至关重要的。然而，我们对 和其他放线菌门中的细胞壁生物合成、功能和结构的了解仍然非常有限。在这里，我们确定 CglA 是将糖聚合物附着到 的细胞壁上所必需的关键酶。我们证明，细胞壁糖聚合物含量的缺陷导致这些丝状细菌失去细胞形状，并表明具有分裂能力的 FtsZ-环不能正确组装并且不能正确定位。结果，隔膜放置受到干扰，导致形成形状异常、活力降低的孢子。
