Azeddoug H, Reysset G
Division of Anaerobics, Pasteur Institute, Paris, France.
Curr Microbiol. 1994 Oct;29(4):229-35. doi: 10.1007/BF01570159.
A 3.3-kb DNA fragment of Clostridium acetobutylicum conferred methyl methane sulfonate (MMS), mitomycin C (MC), and UV resistance to recA strains of E. coli when cloned on the pUC19 plasmid. Analysis of the nucleotide sequence of the total insert and results of in vitro transcription-translation experiments showed that the insert directed the synthesis of three polypeptides referred to as ORFa, ORFb, and ORFc of 23.6, 15.3, and 21 kDa, respectively. None of the polypeptides presented a relationship with the RecA protein of E. coli or products of genes involved in the SOS response. The deduced amino acid sequence of ORFb and ORFc are highly homologous to those deduced from two genes specifying resistance to tellurium salts present on plasmid pMER610 harbored by Alcaligenes sp.strains and to an AMP-binding protein (CABP1) found in Dictyostelium discoideum. The existence of these homologous proteins suggests that they may perform a similar key function in the three unrelated organisms.
丙酮丁醇梭菌的一个3.3 kb DNA片段克隆到pUC19质粒上时，可赋予大肠杆菌recA菌株对甲磺酸甲酯（MMS）、丝裂霉素C（MC）和紫外线的抗性。对整个插入片段的核苷酸序列分析以及体外转录-翻译实验结果表明，该插入片段指导合成了三种多肽，分别称为ORFa、ORFb和ORFc，分子量分别为23.6 kDa、15.3 kDa和21 kDa。这些多肽均与大肠杆菌的RecA蛋白或参与SOS反应的基因产物无关。ORFb和ORFc的推导氨基酸序列与产碱杆菌属菌株携带的质粒pMER610上两个赋予碲盐抗性的基因以及盘基网柄菌中发现的一种AMP结合蛋白（CABP1）的推导氨基酸序列高度同源。这些同源蛋白的存在表明它们可能在这三种不相关的生物体中发挥相似的关键功能。
