Geranoyl-CoA carboxylase: a novel biotin-containing enzyme in plants

Arch Biochem Biophys. 1999 Feb 1;362(1):12-21. doi: 10.1006/abbi.1998.1014.

Abstract

Geranoyl-CoA carboxylase (EC 6.4.1.4) is a biotin-containing enzyme previously described in two genera of bacteria. Here we report the presence of geranoyl-CoA carboxylase in kingdom Plantae. Geranoyl-CoA carboxylase was purified 180-fold from maize leaves. The enzyme has a biotin-containing subunit of 122 kDa. The pH optimum for activity is 8.3. The apparent Km values for the substrates geranoyl-CoA, bicarbonate, and ATP are 64 +/- 5 microM, 0. 58 +/- 0.04 mM, and 8.4 +/- 0.4 microM, respectively. Subcellular fractionations indicate that geranoyl-CoA carboxylase is located in plastids. Geranoyl-CoA carboxylase activity is ubiquitous in organs of monocots and dicots and varies with development. We postulate that geranoyl-CoA carboxylase plays an important role in isoprenoid catabolism in plants, in a pathway analogous to that shown in Psuedomonas sp. In plants, this catabolic pathway would require the interaction of at least three subcellular compartments (plastids, microbodies, and mitochondria) and two biotin-containing enzymes, geranoyl-CoA carboxylase and 3-methylcrotonyl-CoA carboxylase.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biotin / chemistry*
  • Carbon-Carbon Ligases / chemistry*
  • Carbon-Carbon Ligases / isolation & purification
  • Carbon-Carbon Ligases / metabolism
  • Daucus carota
  • Kinetics
  • Organ Specificity
  • Plant Proteins / chemistry*
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism
  • Soybeans
  • Subcellular Fractions / enzymology
  • Zea mays

Substances

  • Plant Proteins
  • Biotin
  • Carbon-Carbon Ligases
  • geranoyl-CoA carboxylase