Publications

• The pca-pob supraoperonic cluster of Acinetobacter calcoaceticus contains quiA, the structural gene for quinate-shikimate dehydrogenase.

  Elsemore D.A., Ornston L.N.

  An 18-kbp Acinetobacter calcoaceticus chromosomal segment contains the pcaIJFBDKCHG operon, which is required for catabolism of protocatechuate, and pobSRA, genes associated with conversion of p-hydroxybenzoate to protocatechuate. The genetic function of the 6.5 kbp of DNA between pcaG and pobS wa ... >> More

  An 18-kbp Acinetobacter calcoaceticus chromosomal segment contains the pcaIJFBDKCHG operon, which is required for catabolism of protocatechuate, and pobSRA, genes associated with conversion of p-hydroxybenzoate to protocatechuate. The genetic function of the 6.5 kbp of DNA between pcaG and pobS was unknown. Deletions in this DNA were designed by removal of fragments between restriction sites, and the deletion mutations were introduced into A. calcoaceticus by natural transformation. The mutations prevented growth with either quinate or shikimate, growth substrates that depend upon qui gene function for their catabolism to protocatechuate. The location of quiA, a gene encoding quinate-shikimate dehydrogenase, was indicated by its expression in one of the deletion mutants, and the position of the gene was confirmed by determination of its 2,427-bp nucleotide sequence. The deduced amino acid sequence of QuiA confirmed that it is a member of a family of membrane-associated, pyrrolo-quinoline quinone-dependent dehydrogenases, as had been suggested by earlier biochemical investigations. Catabolism of quinate and skikimate is initiated by NAD(+)-dependent dehydrogenases in other microorganisms, so it is evident that different gene pools were called upon to provide the ancestral enzyme for this metabolic step. << Less

  J. Bacteriol. 176:7659-7666(1994) [PubMed] [EuropePMC]

• Quinate oxidation in Gluconobacter oxydans IFO3244: purification and characterization of quinoprotein quinate dehydrogenase.

  Vangnai A.S., Toyama H., De-Eknamkul W., Yoshihara N., Adachi O., Matsushita K.

  Quinoprotein quinate dehydrogenase (QDH) is a membrane-bound enzyme containing pyrroloquinoline quinone (PQQ) as the prosthetic group. QDH in Gluconobacter oxydans IFO3244 was found to be inducible by quinate and it is not constitutively expressed in the absence of quinate. The purification of hol ... >> More

  Quinoprotein quinate dehydrogenase (QDH) is a membrane-bound enzyme containing pyrroloquinoline quinone (PQQ) as the prosthetic group. QDH in Gluconobacter oxydans IFO3244 was found to be inducible by quinate and it is not constitutively expressed in the absence of quinate. The purification of holo-form of QDH to nearly homogeneity was achieved. The purified QDH appears to have two subunits of approximately 65 and 21 kDa, which could be the result of proteolysis of single polypeptide. Kinetic analysis indicated that the purified enzyme is much more specific to quinate than QDH from Acinetobacter calcoaceticus. The efficiency of the artificial electron acceptor was also determined. << Less

  FEMS Microbiol Lett 241:157-162(2004) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• 3-dehydroquinate production by oxidative fermentation and further conversion of 3-dehydroquinate to the intermediates in the shikimate pathway.

  Adachi O., Tanasupawat S., Yoshihara N., Toyama H., Matsushita K.

  3-Dehydroquinate production from quinate by oxidative fermentation with Gluconobacter strains of acetic acid bacteria was analyzed for the first time. In the bacterial membrane, quinate dehydrogenase, a typical quinoprotein containing pyrroloquinoline quinone (PQQ) as the coenzyme, functions as th ... >> More

  3-Dehydroquinate production from quinate by oxidative fermentation with Gluconobacter strains of acetic acid bacteria was analyzed for the first time. In the bacterial membrane, quinate dehydrogenase, a typical quinoprotein containing pyrroloquinoline quinone (PQQ) as the coenzyme, functions as the primary enzyme in quinate oxidation. Quinate was oxidized to 3-dehydroquinate with the final yield of almost 100% in earlier growth phase. Resting cells, dried cells, and immobilized cells or an immobilized membrane fraction of Gluconobacter strains were found to be useful biocatalysts for quinate oxidation. 3-Dehydroquinate was further converted to 3-dehydroshikimate with a reasonable yield by growing cells and also immobilized cells. Strong enzyme activities of 3-dehydroquinate dehydratase and NADP-dependent shikimate dehydrogenase were detected in the soluble fraction of the same organism and partially fractionated from each other. Since the shikimate pathway is remote from glucose in the metabolic pathway, the entrance into the shikimate pathway from quinate to 3-dehydroquinate looks advantageous to produce metabolic intermediates in the shikimate pathway. << Less

  Biosci Biotechnol Biochem 67:2124-2131(2003) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.