Schembri M A, Pallesen L, Connell H, Hasty D L, Klemm P
Department of Microbiology, Technical University of Denmark, Lyngby, Denmark.
FEMS Microbiol Lett. 1996 Apr 1;137(2-3):257-63. doi: 10.1111/j.1574-6968.1996.tb08115.x.
The gene encoding the Escherichia coli FimH adhesin of type 1 fimbriae has been subjected to linker insertion mutagenesis. Amino acid changes were introduced at a number of positions spanning the entire sequence in order to probe the structure-function relationship of the FimH protein. The effect of these mutations on the ability of bacteria to express a D-mannose binding phenotype was assessed in a fimH null mutant (MS4) constructed by allelic exchange in the E. coli K-12 strain PC31. Mutations mapping at amino acid residues 36, 58 and 279 of the mature FimH protein were shown to completely abolish binding to D-mannose receptors. Differences in the level of fimbriation were also observed as a result of some of the mutations in the fimH gene. These mutants may prove useful in dissecting receptor-ligand interactions by defining regions of the FimH protein that are important in erythrocyte binding.
编码1型菌毛的大肠杆菌FimH黏附素的基因已进行了接头插入诱变。在跨越整个序列的多个位置引入了氨基酸变化，以探究FimH蛋白的结构-功能关系。在通过大肠杆菌K-12菌株PC31中的等位基因交换构建的fimH基因缺失突变体（MS4）中，评估了这些突变对细菌表达D-甘露糖结合表型能力的影响。定位在成熟FimH蛋白氨基酸残基36、58和279处的突变被证明完全消除了与D-甘露糖受体的结合。由于fimH基因中的一些突变，还观察到了菌毛形成水平的差异。这些突变体可能有助于通过定义FimH蛋白中对红细胞结合重要的区域来剖析受体-配体相互作用。
