Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
J Mol Evol. 2010 Feb;70(2):167-80. doi: 10.1007/s00239-009-9318-2. Epub 2010 Jan 5.
The two-component signal transduction system (TCST) consists of a histidine kinase (HK) and a response regulator (RR). TCSTs play important roles in sensing and reacting to environmental changes, and in bacterial pathogenesis. Previously, we have identified and characterized TCSTs in Erwinia amylovora, a severe plant enterobacterial pathogen, at genome-wide level. Here we conducted a comparative genomic analysis of TCSTs in 53 genomes of 16 enterobacterial species. These species include important plant, animal, human, and insect pathogenic, saprophytic or symbiotic microorganisms. Comparative genomic analysis revealed that enterobacteria contain eight pairs of core TCSTs. Phylogenetic trees reconstructed from a concatenation of the core set of TCSTs from enterobacteria and for individual TCST proteins from species in Proteobacteria showed that most TCST protein trees in the Enterobacteriaceae or in species of the γ-Proteobacteria agreed well with that of the corresponding 16S rRNA gene. It also showed that co-evolutionary relationships existed between cognate partners of the HKs and RRs. Several core TCSTs were quite ancient and universal based on phylogenomic analysis of protein structures. These results indicate that the core TCSTs are relatively conserved, and suggest that these enterobacteria may have maintained their ancient core TCSTs and might acquire specific new TCSTs for their survival in different environments or hosts, or may have evolved new functionalities of the core TCSTs for adaptation to different ecological niches.
双组分信号转导系统(TCST)由组氨酸激酶(HK)和应答调节蛋白(RR)组成。TCST 在感应和应对环境变化以及细菌发病机制中起着重要作用。以前,我们已经在植物肠杆菌病原体 Erwinia amylovora 的全基因组水平上鉴定和表征了 TCST。在这里,我们对 16 种肠杆菌属的 53 个基因组中的 TCST 进行了比较基因组分析。这些物种包括重要的植物、动物、人类和昆虫病原体、腐生菌或共生微生物。比较基因组分析表明,肠杆菌属含有八对核心 TCST。从肠杆菌属的核心 TCST 集合和 Proteobacteria 中各个物种的单个 TCST 蛋白构建的系统发育树表明,肠杆菌科或 γ-Proteobacteria 中的大多数 TCST 蛋白树与相应的 16S rRNA 基因非常吻合。它还表明,HK 和 RR 的同源伴侣之间存在共同进化关系。基于蛋白质结构的系统发育分析,一些核心 TCST 相当古老且普遍。这些结果表明核心 TCST 相对保守,表明这些肠杆菌可能保留了其古老的核心 TCST,并可能为了在不同环境或宿主中生存而获得特定的新 TCST,或者可能为了适应不同的生态位而进化出新的核心 TCST 功能。