Matsuo K, Yamaguchi R, Yamazaki A, Tasaka H, Yamada T
Central Research Laboratories of Ajinomoto Co. Inc., Kawasaki City, Japan.
J Bacteriol. 1988 Sep;170(9):3847-54. doi: 10.1128/jb.170.9.3847-3854.1988.
The gene for the extracellular alpha antigen of Mycobacterium bovis BCG was cloned by using a single probe restricted to G or C in the third position. This technique should have great potential for the isolation of mycobacterial antigen genes. The gene analysis revealed that the alpha antigen gene encoded 323 amino acid residues, including 40 amino acids for signal peptide followed by 283 amino acids for mature protein. This is the first report on the structure of the mycobacterial signal peptide. The promoter-like sequence and ribosome-binding site were observed upstream of the open reading frame. In the coding region, the third position of the codon showed high G + C content (86%). The gene was expressed as an unfused protein in Escherichia coli by using an E. coli expression vector. This protein, which reacted with polyclonal antibody raised against alpha antigen from Mycobacterium tuberculosis, would be applicable to the immunodiagnosis of tuberculosis.
利用一个在第三位仅限制为G或C的单一探针，克隆了卡介苗牛分枝杆菌细胞外α抗原的基因。这项技术在分离分枝杆菌抗原基因方面应该具有很大的潜力。基因分析表明，α抗原基因编码323个氨基酸残基，其中包括40个氨基酸的信号肽，随后是283个氨基酸的成熟蛋白。这是关于分枝杆菌信号肽结构的首次报道。在开放阅读框上游观察到类似启动子的序列和核糖体结合位点。在编码区，密码子的第三位显示出高G + C含量（86%）。通过使用大肠杆菌表达载体，该基因在大肠杆菌中表达为未融合蛋白。这种与针对结核分枝杆菌α抗原产生的多克隆抗体发生反应的蛋白，将适用于结核病的免疫诊断。
