Coenzyme Q(10) (CoQ(10)) is a potent lipophilic antioxidant in cell membranes and a carrier of electrons in the mitochondrial respiratory chain. We previously characterized the effects of varying severities of CoQ(10) deficiency on ROS production and mitochondrial bioenergetics in cells harboring genetic defects of CoQ(10) biosynthesis. We observed a unimodal distribution of ROS production with...

p-Hydroxybenzoate hydroxylase is extensively studied as a model for single-component flavoprotein monooxygenases. It catalyzes a reaction in two parts: (1) reduction of the FAD in the enzyme by NADPH in response to binding of p-hydroxybenzoate to the enzyme and (2) oxidation of reduced FAD with oxygen in an environment free from solvent to form a hydroperoxide, which then reacts with p-hydroxyb...

1. The inducible p-hydroxybenzoate hydroxylase of Pseudomonas putidu which catalyzes the hydroxylation of P-hydroxybenzoate to protocatechuate has been obtained in crystalline form as a protein homogeneous upon ultracentrifugation and electrophoresis. The molecular weight is estimated to be 83,600. 2. The enzyme contains approximately 1 mole of flavin adenine dinucleotide per mole of protein. R...

Glycosylated p-hydroxybenzoic acid methyl esters and structurally related phenolphthiocerol glycolipids are important virulence factors of Mycobacterium tuberculosis. Although both types of molecules are thought to be derived from p-hydroxybenzoic acid, the origin of this putative biosynthetic precursor in mycobacteria remained to be established. We describe the characterization of a transposon...

Lignin is an aromatic heteropolymer, abundantly present in the walls of secondary thickened cells. Although much research has been devoted to the structure and composition of the polymer to obtain insight into lignin polymerization, the low-molecular weight oligolignol fraction has escaped a detailed characterization. This fraction, in contrast to the rather inaccessible polymer, is a simple an...

Structural and kinetic studies have revealed two flavin conformations in p-hydroxybenzoate hydroxylase (PHBH), the in-position and the out-position. Conversion between these two conformations is believed to be essential during catalysis. Although substrate hydroxylation occurs while the flavin in PHBH is in the in-conformation, the position of the flavin during reduction by NADPH is uncertain. ...

The effects of foods and chemicals related to food hygiene on degranulation were evaluated using a method for assaying the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from RBL-2H3 cells in vitro. Using a previously developed assay system, we had found a large number of inhibitors and promoters of degranulation of RBL-2H3 cells. In the present study, we examin...

Here, we describe for the first time the Crc (catabolite repression control) protein from the soil bacterium Acinetobacter baylyi. Expression of A. baylyi crc varied according to the growth conditions. A strain with a disrupted crc gene showed the same growth as the wild type on a number of carbon sources. Carbon catabolite repression by acetate and succinate of protocatechuate 3,4-dioxygenase,...

Comparative phylogenetic analyses of the R2R3-MYB transcription factor family revealed that five subgroups were preferentially found in woody species and were totally absent from Brassicaceae and monocots (Soler et al., 2015). Here, we analyzed one of these subgroups (WPS-I) for which no gene had been yet characterized. Most Eucalyptus members of WPS-I are preferentially expressed in the vascul...

The photosynthetic procaryote Anacystis nidulans converts L-phenylalanine and L-tyrosine into benzoic acid and p-hydroxybenzoic acid, respectively. Results obtained with thylakoid fractions support the hypothesis that the reaction sequence is catalyzed by thylakoid-bound enzyme complexes consisting of phenylalanine ammonia-lyase and benzoate synthase of tyrosine ammonia-lyase and p-hydroxybenzo...