Sauer U, Santangelo J D, Treuner A, Buchholz M, Dürre P
Institut für Mikrobiologie, Georg-August-Universität Göttingen, Germany.
FEMS Microbiol Rev. 1995 Oct;17(3):331-40. doi: 10.1111/j.1574-6976.1995.tb00216.x.
The genus Clostridium, represented by Gram-positive, anaerobic, spore-forming bacteria, is well known for its clinical importance and considerable biotechnological potential. Recently, evidence for a functional role of the transcription factors sigma A, sigma E, sigma G, and sigma K in this genus was provided by cloning and sequencing these genes from C. acetobutylicum. In C. kluyveri, a partially sequenced open reading frame was found to encode the N terminus of the putative sigma factor L with significant similarity to members of the sigma 54 family. The identification of sequences with high similarity to the Bacillus sigma F (C. acetobutylicum), sigma H (several clostridial species), and sigma D (C. thermocellum)-controlled consensus promoters renders the existence of these transcription factors in clostridia very likely. These data are in agreement with information obtained by RNA transcript mapping (sigma A, sigma H), heterologous DNA hybridization (sigma D, sigma H), and immuno characterization of purified proteins (sigma A) from various clostridial species. Thus, the picture emerges that a fundamental similarity exists at the genetic level between the regulation of various cellular responses, in particular sporulation, in the genera Bacillus and Clostridium. The different induction patterns of sporulation in Bacillus spp. (nutrient starvation) and many clostridial species (cessation of growth or exposure to oxygen in the presence of excess nutrients) are most interestingly not reflected in the general regulatory features of this developmental process.
梭菌属以革兰氏阳性、厌氧、产芽孢细菌为代表，因其在临床上的重要性和巨大的生物技术潜力而闻名。最近，通过从丙酮丁醇梭菌中克隆和测序这些基因，为转录因子σA、σE、σG和σK在该属中的功能作用提供了证据。在克氏梭菌中，发现一个部分测序的开放阅读框编码假定的σ因子L的N端，与σ54家族成员具有显著相似性。与芽孢杆菌σF（丙酮丁醇梭菌）、σH（几种梭菌属物种）和σD（热纤梭菌）控制的共有启动子具有高度相似性的序列的鉴定，使得这些转录因子很可能存在于梭菌中。这些数据与通过RNA转录图谱分析（σA、σH）、异源DNA杂交（σD、σH）以及对来自各种梭菌属物种的纯化蛋白进行免疫鉴定（σA）获得的信息一致。因此，出现了这样一种情况：在芽孢杆菌属和梭菌属中，各种细胞反应，特别是孢子形成的调控在遗传水平上存在基本相似性。芽孢杆菌属（营养饥饿）和许多梭菌属物种（在营养过剩的情况下生长停止或暴露于氧气）中孢子形成的不同诱导模式，最有趣的是在这个发育过程的一般调控特征中没有体现出来。
