Nogami T, Mizuno T, Mizushima S
J Bacteriol. 1985 Nov;164(2):797-801. doi: 10.1128/jb.164.2.797-801.1985.
OmpF and OmpC are major outer membrane proteins. Although they are homologous proteins, they function differently in several respects. As an approach to elucidate the submolecular structures that determine the difference, a method was developed to construct a series of ompF-ompC chimeric genes by in vivo homologous recombination between these two genes, which are adjacent on a plasmid. The genomic structures of these chimeric genes were determined by restriction endonuclease analysis and nucleotide sequence determination. In almost all cases, recombination took place between the corresponding homologous regions of the ompF and ompC genes. Many of the chimeric genes produced proteins that migrated to various positions between the OmpF and OmpC proteins on polyacrylamide gel. On the basis of the results, a domain contributing to the mobility difference the OmpF and OmpC proteins was identified. Some chimeric genes did not accumulate outer membrane proteins, despite the fact that the fusion of the ompF and ompC genes was in frame. Bacterial cells possessing the chimeric proteins were also tested as to their sensitivity to phages which require either OmpF or OmpC as a receptor component. The chimeric proteins were either of the OmpF or OmpC type with respect to receptor activity. Based on the observations, the roles of submolecular domains in the structure, function, and biogenesis of the OmpF and OmpC proteins are discussed.
OmpF和OmpC是主要的外膜蛋白。尽管它们是同源蛋白，但在几个方面功能不同。作为阐明决定这种差异的亚分子结构的一种方法，开发了一种通过这两个在质粒上相邻的基因之间的体内同源重组来构建一系列ompF-ompC嵌合基因的方法。通过限制性内切酶分析和核苷酸序列测定确定了这些嵌合基因的基因组结构。在几乎所有情况下，重组都发生在ompF和ompC基因的相应同源区域之间。许多嵌合基因产生的蛋白质在聚丙烯酰胺凝胶上迁移到OmpF和OmpC蛋白之间的不同位置。基于这些结果，确定了一个导致OmpF和OmpC蛋白迁移率差异的结构域。尽管ompF和ompC基因的融合是符合读框的，但一些嵌合基因并没有积累外膜蛋白。还测试了具有嵌合蛋白的细菌细胞对需要OmpF或OmpC作为受体成分的噬菌体的敏感性。就受体活性而言，嵌合蛋白要么是OmpF型，要么是OmpC型。基于这些观察结果，讨论了亚分子结构域在OmpF和OmpC蛋白的结构、功能和生物发生中的作用。
