TABLE 5.

Comparison of properties of benzoate-CoA ligase of T. aromatica with similar aromatic acid-CoA ligases acting on benzoate or 2-aminobenzoatea

EnzymeGrowthRefer- ence(s)Organism or cultureMolecular mass (kDa)Apparent Km values (μM)Substrate preference (% of benzoate)
NativeSDS- PAGEBenzoate2-Amino- benzoateCoA- SHATPBenzoate2-Amino- benzoate2-Fluoro- benzoate3-Fluoro- benzoate4-Fluoro- benzoateCyclohexane carboxylateCyclohexa- 1,5-diene-1- carboxylateCyclohexa- 1-ene-1- carboxylate
Benzoate-CoA ligaseAnaerobicThis workT. aromatica5858161501804401006012289100<1238
Benzoate-CoA ligaseAnaerobic1A. evansii12054930089125100386733547NDbND
Benzoate-CoA ligaseAerobic2A. evansii130561118010527710037155861381NDND
2-Aminobenzoate- CoA ligaseAnaerobic1A. evansii606035132083100100110561003NDND
2-Aminobenzoate- CoA ligaseAerobic1A. evansii6565751526409110010050905NDND
Benzoate-CoA ligaseAnaerobic14a, 17R. palustris60600.6-2ND90-1202-3100<1102ND101ND13
Benzoate-CoA ligaseAnaerobic4Syntrophic4205830ND605601004935675NDND6
Benzoate-CoA ligaseAerobic5aClarkia breweri5964.545ND1309510050NDNDNDNDNDND
  • a Activities of the enzymes described here were determined by the indirect couples spectrophotometric assay with nearly saturating concentrations of the respective cosubstrates ATP (1 mM), CoA (0.4 mM), Mg2+ (0.5 mM), aromatic organic acid (0.5 mM), and alicyclic organic acid (1 mM). None of the following substrates was accepted by any of the described benzoate-CoA ligases (rate, <1%): monochlorobenzoate isomers, monohydroxybenzoate isomers, phenylacetate, 3-aminobenzoate, and 4-aminobenzoate. The only exception is 2-hydroxybenzoate, which was transformed at 5% by the enzyme from R. palustris. Note that Clarkia breweri is a green plant.

  • b ND, not determined.