Archives of Microbiology

, Volume 180, Issue 2, pp 81–87

Quinolinate dehydrogenase and 6-hydroxyquinolinate decarboxylase involved in the conversion of quinolinic acid to 6-hydroxypicolinic acid by Alcaligenes sp. strain UK21

  • Akira Uchida
  • Mina Ogawa
  • Toyokazu Yoshida
  • Toru Nagasawa
Original Paper

DOI: 10.1007/s00203-003-0573-0

Cite this article as:
Uchida, A., Ogawa, M., Yoshida, T. et al. Arch Microbiol (2003) 180: 81. doi:10.1007/s00203-003-0573-0

Abstract

In the conversion of quinolinic acid to 6-hydroxypicolinic acid by whole cells of Alcaligenes sp. strain UK21, the enzyme reactions involved in the hydroxylation and decarboxylation of quinolinic acid were examined. Quinolinate dehydrogenase, which catalyzes the first step, the hydroxylation of quinolinic acid, was solubilized from a membrane fraction, partially purified, and characterized. The enzyme catalyzed the incorporation of oxygen atoms of H2O into the hydroxyl group. The dehydrogenase hydroxylated quinolinic acid and pyrazine-2,3-dicarboxylic acid to form 6-hydroxyquinolinic acid and 5-hydroxypyrazine-2,3-dicarboxylic acid, respectively. Phenazine methosulfate was the preferred electron acceptor for quinolinate dehydrogenase. 6-Hydroxyquinolinate decarboxylase, catalyzing the nonoxidative decarboxylation of 6-hydroxyquinolinic acid, was purified to homogeneity and characterized. The purified enzyme had a molecular mass of approximately 221 kDa and consisted of six identical subunits. The decarboxylase specifically catalyzed the decarboxylation of 6-hydroxyquinolinic acid to 6-hydroxypicolinic acid, without any co-factors. The N-terminal amino acid sequence was homologous with those of bacterial 4,5-dihydroxyphthalate decarboxylases.

Keywords

Quinolinic acid Hydroxylation Quinolinate dehydrogenase 6-Hydroxyquinolinate decarboxylase  Alcaligenes sp. strain UK21 

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Akira Uchida
    • 1
  • Mina Ogawa
    • 1
  • Toyokazu Yoshida
    • 1
  • Toru Nagasawa
    • 1
  1. 1.Department of Biomolecular ScienceGifu UniversityGifuJapan

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