Zwaig N, Nagel de Zwaig R, Istúriz T, Wecksler M
J Bacteriol. 1973 May;114(2):469-73. doi: 10.1128/jb.114.2.469-473.1973.
A spontaneously arising regulatory mutant of the gluconate system in Escherichia coli was isolated. This mutant became constitutive, probably in one step, for gluconate high-affinity transport, gluconokinase, and gluconate-6-P dehydrase. The mutation involved (gntR18) is cotransducible with asd. Pseudorevertants, derived from a mutant (M2) that shows a long lag for growth on gluconate mineral medium, were also isolated and characterized. They give constitutive levels of gluconokinase and gluconate-6-P dehydrase but lack high-affinity transport function. Genetic experiments performed with one of these pseudorevertants (M4) indicate that it carries a secondary mutation in the gntR gene. The M4 phenotype is thus the result of the interaction of expression of a constitutive mutation (gntR4) with the mutation of strain M2 (gntM2).
分离出了大肠杆菌中葡萄糖酸盐系统的一个自发产生的调节突变体。该突变体可能一步到位就组成型表达葡萄糖酸盐高亲和力转运蛋白、葡萄糖激酶和葡萄糖酸-6-磷酸脱水酶。所涉及的突变（gntR18）与 asd 共转导。还分离并鉴定了源自突变体（M2）的假回复突变体，该突变体在葡萄糖酸盐矿物培养基上生长存在长时间延迟。它们组成型表达葡萄糖激酶和葡萄糖酸-6-磷酸脱水酶，但缺乏高亲和力转运功能。对其中一个假回复突变体（M4）进行的遗传实验表明，它在 gntR 基因中携带一个二次突变。因此，M4 表型是组成型突变（gntR4）的表达与菌株 M2（gntM2）的突变相互作用的结果。
