CSIR-Institute of Microbial Technology, Sector-39A, Chandigarh, India.
Department of Microbiology and Molecular Genetics, University of California, Davis, California, USA.
J Bacteriol. 2018 Jan 10;200(3). doi: 10.1128/JB.00620-17. Print 2018 Feb 1.
Chemosensory systems (CSS) are among the most complex organizations of proteins functioning cooperatively to regulate bacterial motility and other cellular activities. These systems have been studied extensively in bacteria, and usually, they are present as a single system. Eight CSS, the highest number in bacteria, have been reported in DK1622 and are involved in coordinating diverse functions. Here, we have explored and compared the CSS in all available genomes of order members contain 97 to 476 two-component system (TCS) proteins, which assist the bacteria in surviving and adapting to varying environmental conditions. The number of myxobacterial CSS ranges between 1 and 12, with the largest number in family and the smallest in CheA protein was used as a phylogenetic marker to infer evolutionary relatedness between different CSS, and six novel CSS ("extra CSS" [ECSS]) were thus identified in the myxobacteria besides the previously reported Che1 to Che8 systems from Che1 to Che8 systems are monophyletic to deltaproteobacteria, whereas the newly identified ECSS form separate clades with different bacterial classes. The comparative modular organization was concordant with the phylogeny. Four clusters lacking CheA proteins were also identified via CheB-based phylogenetic analysis and were categorized as accessory CSS (ACSS). In , an orphan CSS was identified, in which both CheA and CheB were absent. The novel, accessory, and orphan multimodular CSS identified here suggest the emergence of myxobacterial CSS and could assist in further characterizing their roles. This study is focused on chemosensory systems (CSS), which help the bacterium in directing its movement toward or away from chemical gradients. CSS are present as a single system in most of the bacteria except in some groups, including , which has 8 CSS, the highest number reported to date. This is the first comprehensive study carrying out a comparative analysis of the 22 available myxobacterial genomes, which suggests the evolutionary diversity of these systems. We are interested in understanding the distribution of CSS within all known myxobacteria and their probable evolution.
化感感应系统 (CSS) 是蛋白质中最复杂的组织之一，它们协同作用调节细菌的运动和其他细胞活动。这些系统在细菌中已经得到了广泛的研究，通常它们是作为一个单一的系统存在的。在 DK1622 中已经报道了 8 个 CSS，这是细菌中最高的数量，它们参与协调多种功能。在这里，我们探索并比较了所有可用的 成员的基因组中的 CSS，这些成员包含 97 到 476 个双组分系统 (TCS) 蛋白，这些蛋白帮助细菌在不同的环境条件下生存和适应。粘细菌的 CSS 数量在 1 到 12 之间，其中数量最多的是家族，数量最少的是 CheA 蛋白被用作系统发育标记，以推断不同 CSS 之间的进化关系，因此在粘细菌中除了以前报道的 Che1 到 Che8 系统外，还鉴定了六个新的 CSS（“额外 CSS”[ECSS]）。Che1 到 Che8 系统与δ变形菌是单系的，而新鉴定的 ECSS 与不同的细菌类群形成了单独的分支。比较模块化组织与系统发育一致。通过基于 CheB 的系统发育分析还鉴定了四个缺乏 CheA 蛋白的簇，并将其归类为辅助 CSS（ACSS）。在 中，鉴定了一个孤 CSS，其中 CheA 和 CheB 都不存在。这里鉴定的新的、辅助的和孤的多模块 CSS 表明了粘细菌 CSS 的出现，并可能有助于进一步描述它们的作用。这项研究主要集中在化感感应系统 (CSS) 上，它帮助细菌朝着或远离化学梯度移动。除了一些群体外，包括 ，大多数细菌中的 CSS 都是作为一个单一的系统存在的，而 有 8 个 CSS，是迄今为止报道的最高数量。这是第一次对 22 个可用的粘细菌基因组进行全面的比较分析，这表明了这些系统的进化多样性。我们有兴趣了解 CSS 在所有已知粘细菌中的分布及其可能的进化。
