APPARENT BACTERIOPHAGE-BINDING REGION OF AN ESCHERICHIA-COLI K-12 OUTER-MEMBRANE PROTEIN
APPARENT BACTERIOPHAGE-BINDING REGION OF AN ESCHERICHIA-COLI K-12 OUTER-MEMBRANE PROTEIN
复制标题
DOI：
10.1128/jb.153.2.581-587.1983
复制
发表时间：
1983-01-01
影响因子：
3.2
通讯作者：
HENNING, U
中科院分区：
文献类型：
--
作者：
COLE, ST;CHENSCHMEISSER, U;HENNING, U
OmpA蛋白是大肠杆菌的主要外膜蛋白之一，由325个氨基酸残基组成。杆菌它作为几种T偶联蛋白的受体，是某些大肠杆菌素作用和结合中交配聚集体稳定所必需的。克隆的ompA基因的两个突变等位基因被分离，其产生不再作为噬菌体受体起作用的蛋白质。拥有突变蛋白的细菌不能可逆或不可逆地结合β-内酰胺酶。这两种蛋白质仍然在缀合中起作用，并且其中一种赋予大肠杆菌素L敏感性。DNA序列分析表明，1个突变体表现出的噬菌体抗性、大肠杆菌素敏感性表型是由于氨基酸取代Gly →。在位置70处的Arg。第二个突变体含有串联重复，编码具有8个额外氨基酸残基的较大产物，其中7个是残基57-63之间的序列的重复。与野生型OmpA蛋白相反，当用酶处理完整细胞时，该衍生物被链霉蛋白酶部分消化。该蛋白酶去除了64个NH 2末端残基，表明这部分蛋白质暴露于外部。噬菌体受体位点最有可能位于OmpA蛋白的残基60-70周围，并且所表征的改变直接影响该位点。
The 325-residue OmpA protein is one of the major outer membrane proteins of E. coli. It serves as the receptor for several, T-even-like phages and is required for the action of certain colicins and for the stabilizatin of mating aggregates in conjugation. Two mutant alleles of the cloned ompA gene were isolated, which produce a protein that no longer functions as a phage receptor. Bacteria possessing the mutant proteins were unable to bind the phages, reversibly or irreversibly. Both proteins still functioned in conjugation, and one of them conferred colicin L sensitivity. DNA sequence analysis showed that the phage-resistant, colicin-sensitive phenotype exhibited by 1 mutant was due to the amino acid substitution Gly .fwdarw. Arg at position 70. The 2nd mutant, which contained a tandem duplication, encodes a larger product with 8 additional amino acid residues, 7 of which are a repeat of the sequence between residues 57-63. In contrast to the wild-type OmpA protein, this derivative was partially digested by pronase when intact cells were treated with the enzyme. The protease removed 64 NH2-terminal residues, indicating that this part of the protein is exposed to the outside. The phage receptor site is most likely situated around residues 60-70 of the OmpA protein, and the alterations characterized have directly affected this site.