Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany.
Department of Biology, Philipps-Universität Marburg, Marburg, Germany.
mBio. 2020 Jun 30;11(3):e00306-20. doi: 10.1128/mBio.00306-20.
is an alphaproteobacterium belonging to the Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal, and all Rgs proteins, except for RgsE, were indispensable for cell growth. Six of the Rgs proteins, TolQ, and Pal localized to the growing cell pole in the cell elongation phase and to the septum in predivisional cells, and three Rgs proteins localized to the growing cell pole only. The putative FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of the Rgs proteins showed that they are conserved in and mostly absent from other alphaproteobacterial orders, suggesting a conserved role of these proteins in polar growth. Bacterial cell proliferation involves cell growth and septum formation followed by cell division. For cell growth, bacteria have evolved different complex mechanisms. The most prevalent growth mode of rod-shaped bacteria is cell elongation by incorporating new peptidoglycans in a dispersed manner along the sidewall. A small share of rod-shaped bacteria, including the alphaproteobacterial , grow unipolarly. Here, we identified and initially characterized a set of Rgs (rhizobial growth and septation) proteins, which are involved in cell division and unipolar growth of and highly conserved in Our data expand the knowledge of components of the polarly localized machinery driving cell wall growth and suggest a complex of Rgs proteins with components of the divisome, differing in composition between the polar cell elongation zone and the septum.
是一种α变形菌，属于该目的细菌通过细胞分裂在新的细胞极生成来延长细胞壁。为了筛选先前表征的极生长因子 RgsP 和 RgsM 的蛋白质相互作用伙伴，我们鉴定了 Tol-Pal 系统（TolQ 和 TolR）的内膜成分和具有未知功能的新型 Rgs（根瘤菌生长和分隔）蛋白。除了 RgsE 之外，TolQ、Pal 和所有 Rgs 蛋白对于 细胞生长都是必不可少的。在细胞伸长阶段，Rgs 蛋白、TolQ 和 Pal 定位在生长的细胞极，在细胞分裂前定位在隔膜上，而三种 Rgs 蛋白仅定位在生长的细胞极。假定的 FtsN 样蛋白 RgsS 含有保守的 SPOR 结构域，在细胞分裂的早期阶段是必不可少的。Tol-Pal 系统的成分在细胞分裂的后期阶段是必需的。RgsE，一种生长极环蛋白 GPR 的同源物，在维持正常生长速率和杆状细胞形状方面起着重要作用。RgsD 是一种具有结合肽聚糖能力的周质蛋白。对 Rgs 蛋白的系统发育分布分析表明，它们在 中保守，而在其他α变形菌目中大多缺失，这表明这些蛋白在极生长中具有保守作用。细菌细胞增殖涉及细胞生长和隔膜形成，然后是细胞分裂。对于细胞生长，细菌已经进化出不同的复杂机制。杆状细菌最常见的生长模式是通过在侧壁上以分散的方式掺入新的肽聚糖来进行细胞伸长。一小部分杆状细菌，包括α变形菌纲的 ，呈单极生长。在这里，我们鉴定并初步表征了一组 Rgs（根瘤菌生长和分隔）蛋白，它们参与 细胞分裂和单极生长，在 中高度保守。我们的数据扩展了驱动细胞壁生长的极化定位机制的组件的知识，并提出了一个 Rgs 蛋白与分裂体组件的复合物，其组成在极性细胞伸长区和隔膜之间有所不同。
