Beyersmann D, Messer W, Schlicht M
J Bacteriol. 1974 Jun;118(3):783-9. doi: 10.1128/jb.118.3.783-789.1974.
Mutagenized E. coli B/r cells were subjected to a procedure designed to select mutants temperature-sensitive for initiation of deoxyribonucleic acid (DNA) replication. Seventeen mutants exhibiting limited residual DNA synthesis at 42 C were obtained and the dna(-) sites were mapped genetically. Sixteen of the sites map near dnaA, dnaB, and dnaC. One mutant (dna-208) maps in a new location between the trp and his genes. We propose to call this mutant dnaI208. In complementation experiments dnaC(+) and dnaI(+) were dominant to dnaC(-) and dnaI(-) alleles, respectively. However, dnaA(-) was dominant to the wild-type allele dnaA(+). All dnaA mutants and four out of six dnaC mutants could be suppressed by F factor integration. The pattern of suppression was specific for each mutant.
对诱变后的大肠杆菌B/r细胞进行了一项程序,旨在筛选对脱氧核糖核酸(DNA)复制起始温度敏感的突变体。获得了17个在42℃时表现出有限残留DNA合成的突变体,并对dna(-)位点进行了遗传定位。其中16个位点位于dnaA、dnaB和dnaC附近。一个突变体(dna-208)位于trp和his基因之间的一个新位置。我们提议将这个突变体称为dnaI208。在互补实验中,dnaC(+)和dnaI(+)分别对dnaC(-)和dnaI(-)等位基因呈显性。然而,dnaA(-)对野生型等位基因dnaA(+)呈显性。所有dnaA突变体和六个dnaC突变体中的四个都可以通过F因子整合得到抑制。抑制模式对每个突变体都是特异性的。