In lactococci, transamination is the first step of the enzymatic conversion of aromatic and branched-chain amino acids to aroma compounds. In previous work we purified and biochemically characterized the major aromatic aminotransferase (AraT) of a Lactococcus lactis subsp. cremoris strain. Here we characterized the corresponding gene and evaluated the role of AraT in the biosynthesis of amino a...

Motivation: T-box antitermiantion is the most distributed mechanism of regulation of various amino acids in Gram-positive bacteria. Identification of the T-box regulon and a metabolic analysis of amino acid biosynthesis and transport is one of problems of comparative genetics, genomics and molecular biology. Results: Search for T-box elements and analysis of operon structures identified a large...

The yeast LPD1 gene encoding lipoamide dehydrogenase is subject to the general control of amino acid biosynthesis mediated by the GCN4 transcription factor. This is striking in that it demonstrates that GCN4-mediated regulation extends much farther upstream than simply to the direct pathways for amino acid and purine biosynthesis. In yeast, lipoamide dehydrogenase functions in at least three mu...

The biosynthesis of the azamacrolide epilachnene by the coccinellid beetle Epilachna varivestis has been studied with 2H-labeled oleic acid, 2H-labeled L-serine, and 13C,15N-labeled L-serine. The incorporation of these precursors into epilachnene defines the origin of the alkaloid's entire carbon/nitrogen skeleton. GC/MS and GC/IR studies of alkaloid produced by Epilachna fed with deuteriated o...

Pigment biosynthesis in the cyanobacterium, Anacystis nidulans, was examined in the presence of gabaculine (5-amino-1,3-cyclohexadienyl-carboxylic acid). At 20 micromolar, this inhibitor blocked the biosynthesis of both chlorophyll and phycocyanin. Analogs of gabaculine were not effective as inhibitors of chlorophyll or phycocyanin biosynthesis. Iron- and phosphate-deficient cultures were 2- to...

The aromatic amino acids phenylalanine, tyrosine and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are important for plant growth as well as for human nutrition and health. The aromatic amino acids are synthesized via the shikimate pathway followed by the branched aromatic amino acid metab...

To better understand lipid biosynthesis in oil palm mesocarp, in particular the differences in gene regulation leading to and including de novo fatty acid biosynthesis, a multi-platform metabolomics technology was used to profile mesocarp metabolites during six critical stages of fruit development in comparatively high- and low-yielding oil palm populations. Significantly higher amino acid leve...

Previous investigations have indicated that [`4C]glycine is incorporated into erythrocyte glutathione at a rate which exceeds by severalfold the rate of cysteine and glutamate incorporation. The discrepancy between the rates has generally been attributed to the known differences in the rates at which these amino acids are transported into erythrocytes. In the present investigation, human erythr...

Drought is a major limiting factor of Brassica napus (rapeseed) and potassium (K) plays important roles in rapeseed drought tolerance. Previous studies have reported that cultivars characterized by different K status showed contrasting However, the molecular mechanism underlying tolerance remains unclear. In this study, comparative transcriptome analysis was conducted between drought-tolerant c...

in this study, we investigate the potential of moricandia arvensis methanol leaf extract (meohl) on calpain activity, melanin biosynthesis and dna mutagenicity. cytotoxic effect and measurement of reactive oxygen species (ros) induced by lucigenin in colorectal cells (be) were also determined. in addition the chemical analysis of the extract was also studied and the chemical profile illustrates...