Hales B A, Beverley-Clarke H, High N J, Jann K, Perry R, Goldhar J, Boulnois G J
Department of Microbiology, University of Leicester, U.K.
Microb Pathog. 1988 Jul;5(1):9-17. doi: 10.1016/0882-4010(88)90076-9.
A non-fimbrial adhesin (NFA-1) from the uropathogenic Escherichia coli strain 827 responsible for agglutination of human erythrocytes was cloned using the cos 4 cosmid vector. A clone was isolated which promoted haemagglutination and showed the same biological properties as the adhesin produced by the wild type strain. Both express adhesin at 37 degrees C, but not 18 degrees C nor in the presence of 1% glucose. Adhesin purified from the clone formed high molecular weight aggregates which were resolved to the 21 K dalton subunit protein seen in the wild type strain on denaturation. Binding to human kidney cells by the clone and the wild type E. coli, from which the genes were cloned, were compared in an ELISA assay and shown to be the same. The genes for the adhesin were isolated on a 15.5 kilobase BamHI-EcoRI fragment which was subjected to gamma delta mutagenesis. The NFA-1 operon was localised to a 6.5kb region of this fragment.
利用cos 4黏粒载体克隆了来自尿路致病性大肠杆菌827菌株的一种非菌毛黏附素（NFA-1），该黏附素可导致人红细胞凝集。分离出一个克隆，它能促进血细胞凝集，且表现出与野生型菌株产生的黏附素相同的生物学特性。二者在37℃时均表达黏附素，但在18℃时或存在1%葡萄糖的情况下不表达。从该克隆中纯化的黏附素形成了高分子量聚集体，这些聚集体在变性后分解为野生型菌株中可见的21千道尔顿亚基蛋白。通过酶联免疫吸附测定（ELISA）比较了该克隆与克隆出其基因的野生型大肠杆菌对人肾细胞的结合情况，结果显示二者相同。黏附素基因在一个15.5千碱基的BamHI - EcoRI片段上分离出来，并对其进行了γδ诱变。NFA - 1操纵子定位于该片段的一个6.5kb区域。
