Molecular Analysis of an Extrachromosomal Element Containing the C2 Toxin Gene Discovered in Clostridium botulinum Type C
Molecular Analysis of an Extrachromosomal Element Containing the C2 Toxin Gene Discovered in Clostridium botulinum Type C
复制标题
C 型肉毒杆菌中发现的含有 C2 毒素基因的染色体外元件的分子分析
作者：
Y. Sakaguchi;Tetsuya Hayashi;Yumiko Yamamoto;K. Nakayama;Kai Zhang;Shaobo Ma;H. Arimitsu;K. Oguma
根据产生的神经毒素的抗原性，肉毒梭菌培养物可分为A型至G型7种。在这7种类型中，除了神经毒素外，只有C型和D型产生C2毒素。C2毒素由C2I和C2II两种成分组成。编码C2毒素成分的基因已经被克隆出来，并且已经声明它们可能在细胞染色体上。本研究通过脉冲场凝胶电泳和随后的Southern杂交证实了这些基因位于一个大质粒上。采用反相PCR和引物行走相结合的方法确定了该质粒的完整核苷酸序列。该序列长106,981 bp，包含123个潜在开放阅读框，包括c2I和c2II基因。这些开放阅读框的57个产物具有与已知蛋白质相似的序列。推测这57个基因产物中有9个与DNA复制有关，2个与双组分调控系统有关，3个是σ因子。此外，在两个区域共发现了20个编码嘌呤分解代谢不同过程相关蛋白的基因。在这些区域，有9个和11个基因在质粒中很少发现，表明该质粒在嘌呤分解代谢和C2毒素产生中起重要作用。
ABSTRACT Clostridium botulinum cultures are classified into seven types, types A to G, based on the antigenicity of the neurotoxins produced. Of these seven types, only types C and D produce C2 toxin in addition to the neurotoxin. The C2 toxin consists of two components designated C2I and C2II. The genes encoding the C2 toxin components have been cloned, and it has been stated that they might be on the cell chromosome. The present study confirmed by using pulsed-field gel electrophoresis and subsequent Southern hybridization that these genes are on a large plasmid. The complete nucleotide sequence of this plasmid was determined by using a combination of inverse PCR and primer walking. The sequence was 106,981 bp long and contained 123 potential open reading frames, including the c2I and c2II genes. The 57 products of these open reading frames had sequences similar to those of well-known proteins. It was speculated that 9 these 57 gene products were related to DNA replication, 2 were responsible for the two-component regulatory system, and 3 were σ factors. In addition, a total of 20 genes encoding proteins related to diverse processes in purine catabolism were found in two regions. In these regions, there were 9 and 11 genes rarely found in plasmids, indicating that this plasmid plays an important role in purine catabolism, as well as in C2 toxin production.
影响因子：
7
作者：
Sebaihia, Mohammed;Peck, Michael W.;Parkhill, Julian
通讯作者：
Parkhill, Julian