Stern A, Nickel P, Meyer T F, So M
Cell. 1984 Jun;37(2):447-56. doi: 10.1016/0092-8674(84)90375-1.
In N. gonorrhoeae, the expression of pilus and opacity (Op) proteins can be switched on and off and a single cell apparently has a whole repertoire of genes to express many serologically distinguishable protein types. We describe the isolation of several different Op genes and of nonexpressing gene equivalents, all derived from isogenic gonococcal variants. In the E. coli host, Op proteins identical with those made in the respective N. gonorrhoeae strain are produced. The Op genes map near the pilus expression locus. Genomic blotting experiments with an Op gene probe reveal complex hybridization patterns but little heterogeneity among the genes of Op variants. It appears that colonial variation involving the Op protein of N. gonorrhoeae is based on minor sequence alterations, in contrast to the pilus variation system, in which changes in the expression can be evoked by substantial genomic rearrangements.
在淋病奈瑟菌中，菌毛蛋白和不透明（Op）蛋白的表达可以开启和关闭，而且单个细胞显然具有一整套基因来表达许多血清学上可区分的蛋白类型。我们描述了几种不同Op基因以及非表达基因等效物的分离，所有这些都源自同基因的淋球菌变体。在大肠杆菌宿主中，产生了与相应淋病奈瑟菌菌株中产生的蛋白相同的Op蛋白。Op基因定位于菌毛表达位点附近。用Op基因探针进行的基因组印迹实验揭示了复杂的杂交模式，但Op变体的基因之间几乎没有异质性。与菌毛变异系统相反，涉及淋病奈瑟菌Op蛋白的菌落变异似乎是基于微小的序列改变，在菌毛变异系统中，表达的变化可由大量的基因组重排引起。
