Hanson M S, Brinton C C
Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
Nature. 1988 Mar 17;332(6161):265-8. doi: 10.1038/332265a0.
The type-1 pilus of Escherichia coli is the prototype of this class of hair-like, multimeric adhesive organelles. This pilus mediates adherence to mannose-containing receptors on mucosal epithelia and other cells. The type-1 pilus, in one of several serological variants, is expressed by nearly all E. coli strains, and its promotion of colonization by pathogenic bacteria and the protective effects of purified pilus vaccines suggest that it is important as a bacterial virulence factor. Both the adhesive function and the serological variation of the type-1 pilus have been attributed to the thousand or so pilin protein monomers making up the pilus rods. This idea has been contradicted by our earlier observations on an E. coli strain expressing adhesion-defective pili. More recent genetic evidence also indicates that auxiliary pilus proteins are required for adhesive function. We report here the identification of three previously undetected integral minor proteins on the type-1 pilus, and show that one of them is the receptor-binding adhesin. This protein is antigenically conserved among strains with different pilin serotypes and is located at the pilus tip.
大肠杆菌的1型菌毛是这类毛发状多聚体粘附细胞器的原型。这种菌毛介导细菌粘附于粘膜上皮和其他细胞上含甘露糖的受体。1型菌毛存在多种血清学变体，几乎所有大肠杆菌菌株都能表达，其在病原菌定殖过程中的促进作用以及纯化菌毛疫苗的保护作用表明，它作为一种细菌毒力因子具有重要意义。1型菌毛的粘附功能和血清学变异都归因于构成菌毛杆的约一千个菌毛蛋白单体。我们早期对一株表达粘附缺陷型菌毛的大肠杆菌菌株的观察结果与这一观点相矛盾。最近的遗传学证据也表明，粘附功能需要辅助菌毛蛋白。我们在此报告在1型菌毛上鉴定出三种先前未检测到的整合性次要蛋白，并表明其中一种是受体结合粘附素。这种蛋白在具有不同菌毛蛋白血清型的菌株中具有抗原保守性，且位于菌毛顶端。
