Publications

• 2-keto-3-deoxygluconate transport system in Erwinia chrysanthemi.

  Condemine G., Robert-Baudouy J.

  In Erwinia chrysanthemi, the gene kdgT encodes a transport system responsible for the uptake of ketodeoxyuronates. We studied the biochemical properties of this transport system. The bacteria could grow on 2,5-diketo-3-deoxygluconate but not on 2-keto-3-deoxygluconate. The 2-keto-3-deoxygluconate ... >> More

  In Erwinia chrysanthemi, the gene kdgT encodes a transport system responsible for the uptake of ketodeoxyuronates. We studied the biochemical properties of this transport system. The bacteria could grow on 2,5-diketo-3-deoxygluconate but not on 2-keto-3-deoxygluconate. The 2-keto-3-deoxygluconate entry reaction displayed saturation kinetics, with an apparent Km of 0.52 mM (at 30 degrees C and pH 7). 5-Keto-4-deoxyuronate and 2,5-diketo-3-deoxygluconate appeared to be competitive inhibitors, with Kis of 0.11 and 0.06 mM, respectively. The 2-keto-3-deoxygluconate permease could mediate the uptake of glucuronate with a low affinity. kdgT was cloned on an R-prime plasmid formed by in vivo complementation of a kdgT mutation of Escherichia coli. After being subcloned, it was mutagenized with a mini-Mu-lac transposable element able to form fusions with the lacZ gene. We introduced a kdgT-lac fusion into the E. chrysanthemi chromosome by marker exchange recombination and studied its regulation. kdgT product synthesis was not induced by external 2-keto-3-deoxygluconate in the wild-type strain but was induced by galacturonate and polygalacturonate. Two types of regulatory mutants able to grow on 2-keto-3-deoxygluconate as the sole carbon source were studied. Mutants of one group had a mutation in the operator region of kdgT; mutants of the other group had a mutation in kdgR, a regulatory gene controlling kdgT expression. << Less

  J Bacteriol 169:1972-1978(1987) [PubMed] [EuropePMC]

• Construction and expression of hybrid plasmids containing the structural gene of the Escherichia coli K-12 3-deoxy-2-oxo-D-gluconate transport system.

  Mandrand-Berthelot M.A., Ritzenthaler P., Mata-Gilsinger M.

  The kdgT gene of Escherichia coli, which encodes for the 3-deoxy-2-oxo-D-gluconate transport system, was isolated as a ColE1-kdgT hybrid plasmid from the Clarke and Carbon bank. A restriction and genetic map of the min 88 region of the chromosome was established; by subcloning the restriction frag ... >> More

  The kdgT gene of Escherichia coli, which encodes for the 3-deoxy-2-oxo-D-gluconate transport system, was isolated as a ColE1-kdgT hybrid plasmid from the Clarke and Carbon bank. A restriction and genetic map of the min 88 region of the chromosome was established; by subcloning the restriction fragments into the plasmid vector pBR322, the kdgT gene was localized on a 1.4-megadalton PstI DNA fragment, and the direction of transcription of the gene was determined by making use of an in vitro gene fusion between kdgT and lacZ genes. Amplification of the gene product of kdgT was up to 14-fold the level found in a haploid strain. When plasmids bearing kdgT were expressed in an in vivo maxicell system, a specific polypeptide of 28,000 daltons appeared that was found to be associated with the membrane fraction. << Less

  J Bacteriol 160:600-606(1984) [PubMed] [EuropePMC]