Jonsson Maria, Sven Bergström
Department of Microbiology, University of Umea,S-901 87 Umeå,Sweden.
Microbiology (Reading). 1995 Jun;141 ( Pt 6):1321-1329. doi: 10.1099/13500872-141-6-1321.
The major outer surface proteins of Lyme disease spirochaetes are differentially expressed in different isolates. Borrelia afzelii strain F1 expresses none, or very low amounts, of the OspA and OspB proteins. To elucidate the mechanisms that control the expression of these abundant surface proteins the ospAB operon of B. afzelii F1 was cloned, sequenced and compared to the previously sequenced ospAB operon of B. afzelii ACAI and Borrelia burgdorferi B31. The two B. afzelii strains showed almost 100% identity at the DNA level, although Coomassie-stained gels and Western blot analyses showed significant variation in the Osp protein content. Transcriptional analysis revealed that the amount of ospAB mRNA produced in B. afzelii F1 varies more than the amount of protein, suggesting that the expression of OspA and OspB proteins is regulated at both the transcriptional and the translational level. Furthermore, the inverse relationship between the transcription of ospC and the ospAB operon could indicate coregulation of these separately encoded operons.
莱姆病螺旋体的主要外表面蛋白在不同分离株中差异表达。阿氏疏螺旋体菌株F1不表达或仅表达极少量的OspA和OspB蛋白。为阐明控制这些丰富表面蛋白表达的机制，对阿氏疏螺旋体F1的ospAB操纵子进行了克隆、测序，并与先前测序的阿氏疏螺旋体ACAI和伯氏疏螺旋体B31的ospAB操纵子进行比较。尽管考马斯亮蓝染色凝胶和蛋白质印迹分析显示Osp蛋白含量存在显著差异，但这两种阿氏疏螺旋体菌株在DNA水平上显示出近100%的同一性。转录分析表明，阿氏疏螺旋体F1中产生的ospAB mRNA量的变化大于蛋白量的变化，这表明OspA和OspB蛋白的表达在转录和翻译水平上均受到调控。此外，ospC转录与ospAB操纵子之间的反向关系可能表明这些单独编码的操纵子存在共同调控。
