Mutations affecting gluconate catabolism in Escherichia coli. Genetic mapping of the locus for the thermosensitive gluconokinase

J Gen Microbiol. 1986 Nov;132(11):3209-19. doi: 10.1099/00221287-132-11-3209.


An Escherichia coli strain unable to use gluconate was isolated by spontaneous curing of lambda cI857 s7 xis6 b515 b519, lambda cI857 s7 delta(A-att) dargI valS lysogens. Two lesions, linked to asd and pyrB markers, respectively, were necessary to produce this phenotype. The asd-linked mutation gnt-17, of regulatory type, seems to affect the expression of the major system of gluconate utilization (min 75) as well as that of 6-phosphogluconate dehydratase (gene edd, min 41), the first enzyme of the Entner-Doudoroff pathway. A closely linked suppressor of gnt-17 causes constitutivity of these activities; this suppressor resembles gntR, which is also in the asd region. Hence, it is possible that gnt-17 is a super-repressing allele of gntR, rather than a positive controlling element. Lesion gnt-17 alone does not prevent the utilization of gluconate; for this, the mutation gnt-18 at 96.9 min is also necessary. This mutation abolishes the thermosensitive gluconokinase activity and thus eliminates the subsidiary ability to catabolize gluconate. Accordingly, gnt-18 seems to be allelic with gntV, the locus postulated as being in the pyrB region specifying the thermosensitive gluconokinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Mapping*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Gluconates / metabolism*
  • Mutation*
  • Phosphotransferases (Alcohol Group Acceptor)*
  • Phosphotransferases / genetics*
  • Transduction, Genetic


  • Gluconates
  • Phosphotransferases
  • Phosphotransferases (Alcohol Group Acceptor)
  • gluconokinase