Molecular characterization and expression analysis of the superoxide dismutase gene from Streptococcus agalactiae
Molecular characterization and expression analysis of the superoxide dismutase gene from Streptococcus agalactiae
复制标题
DOI：
10.1016/s0378-1119(97)00548-9
复制
发表时间：
1997-12-19
期刊：
影响因子：
3.5
通讯作者：
Trieu-Cuot, P
中科院分区：
文献类型：
--
作者：
Gaillot, O;Poyart, C;Trieu-Cuot, P
我们已经克隆并测序了一个3103 bp的DNA片段携带的基因编码的Mn-SOD从无乳链球菌NEM 318血清型III。该DNA片段含有四个具有相同转录极性的orfs。Orf 1被截短的分子克隆和相应的228-aa长的多肽没有表现出任何显着的同源性与其他同源蛋白。Orf 2编码345个氨基酸的蛋白质，其与枯草芽孢杆菌的YqeN肽显示出一些相似性（29%同一性），其功能未知。Orf 3编码202 aa的Mn-SOD，在大肠杆菌中得到了功能性表达。Orf 4也被截短的分子克隆和编码的99个氨基酸的N-末端部分的蛋白质，显示显着的同源性（40%的f的同一性）与抗终止子的LicT的B。枯草杆菌。转录分析表明，S.无乳NEM 318从启动子单顺反子转录，其活性既不受培养基的pH、O-2也不受CO2浓度调节。高分辨琼脂糖凝胶电泳分析野生型沙门氏菌sodA基因座的DNA多态性。属于血清组I、II或III的无乳症显示没有可检测的差异。(C)1997年Elsevier Science B.V.
We have cloned and sequenced a 3103-bp DNA fragment carrying the gene encoding the Mn-SOD from Streptococcus agalactiae NEM318 serotype III. This DNA fragment contained four orfs that have the same polarity of transcription. Orf1 was truncated by molecular cloning and the corresponding 228-aa-long polypeptide did not exhibit any significant homology with other cognate proteins. Orf2 encodes a protein of 345 aa that displays some similarity (29% identity) with the YqeN peptide of Bacillus subtilis, the function of which is unknown. Orf3 encodes the 202-aa-long Mn-SOD which was functionally expressed in Escherichia coli. Orf4 was also truncated by molecular cloning and encodes 99 aa of the N-terminal moiety of a protein that displays significant homology (40% f identity) with the antiterminator LicT of B. subtilis. Transcriptional analysis revealed that the sodA gene of S. agalactiae NEM318 was transcribed monocistronically from a promoter, the activity of which is neither regulated by pH, O-2, nor CO2 concentrations of the culture medium. Analysis by high resolution agarose gel electrophoresis of the AluI DNA polymorphism of the sodA locus in wild-type strains of S. agalactiae belonging to serogroups I, II, or III revealed no detectable difference. (C) 1997 Elsevier Science B.V.