We have generated antisense plants of Brassica napus, targeting either the cytoplasmic Type I acetyl-CoA carboxylase or the beta-ketoacyl-acyl carrier protein reductase of the Type II dissociable fatty acid synthase, in order to investigate the importance of these components in regulating lipid metabolism in plants. Using a range of down-regulated plants, it has become clear that down-regulatio...

The enzymes of mitochondrial beta-oxidation are thought to be organized in at least two functional complexes, a membrane-bound, long-chain-specific beta-oxidation system and a matrix system consisting of soluble enzymes with preferences for medium-chain and short-chain substrates. This hypothesis is supported by the observation that the inactivation of long-chain 3-ketoacyl-CoA thiolase by 4-br...

Peroxisomes play an important role in cellular defense systems and generate secondary messengers for cellular communication. Saccharomyces cerevisiae containing oleate-induced peroxisomes were subjected to buffer-soluble extraction and two chromatographic procedures, and a protein with antifungal activity was isolated. The results of MALDI-TOF analysis identified the isolated protein as peroxis...

The de novo synthesis of fatty acids occurs in two distinct cellular compartments. Palmitate (16:0) is synthesized from acetyl-CoA and malonyl-CoA in the cytoplasm by the enzymes acetyl-CoA carboxylase 1 and fatty acid synthase. The synthesis of fatty acids longer than 16 carbons takes place in microsomes and utilizes malonyl-CoA as the carbon source. Each two-carbon addition requires four sequ...

To prepare medium-chain-length poly-3-hydroxyalkanoates (PHAs) with altered physical properties, we generated recombinant Escherichia coli strains that synthesized PHAs with altered monomer compositions. Experiments with different substrates (fatty acids with different chain lengths) or different E. coli hosts failed to produce PHAs with altered physical properties. Therefore, we engineered a n...

Since the discovery and sequencing of 6-deoxyerythronolide B synthase 20 years ago, this exceptionally large, multifunctional protein remains the paradigm for the understanding of the structure and biochemical function of modular polyketide synthases. The broad-spectrummacrolide antibiotic erythromycin is one of several hundred closely related, branched chain, polyoxygenated polyketides, many o...

The enzymes for beta-oxidation of fatty acids in inducible and constitutive strains of Escherichia coli were assayed in soluble and membrane fractions of disrupted cells by using fatty acid and acyl-coenzyme A (CoA) substrates containing either 4 or 16 carbon atoms in the acyl moieties. Cell fractionation was monitored, using succinic dehydrogenase as a membrane marker and glucose 6-phosphate d...

Chalcone synthase (CHS) and stilbene synthase (STS) catalyse condensation reactions of p-coumaroyl-CoA and three C(2) units from malonyl-CoA up to a common tetraketide intermediate but then catalyse different cyclization reactions to produce naringenin chalcone and resveratrol respectively. On the basis of sequence alignment with other condensing enzymes including 3-ketoacyl-(acyl carrier prote...

The exact biosynthetic pathways leading to benzoic acid (BA) formation in plants are not known, but labeling experiments indicate the contribution of both beta-oxidative and non-beta-oxidative pathways. In Petunia hybrida BA is a key precursor for the production of volatile benzenoids by its flowers. Using functional genomics, we identified a 3-ketoacyl-CoA thiolase, PhKAT1, which is involved i...