The subunit locations of the five enzymes associated with the fatty acid oxidation complex from Escherichia coli were studied by immunotitration and chemical modification. Antibodies raised against the purified complex caused the parallel inhibitions of enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase, while slightly stimulating 3-ketoacyl-CoA thiolase. All five component enzymes of the ...

The Streptomyces glaucescens beta-ketoacyl-acyl carrier protein (ACP) synthase III (KASIII) initiates straight- and branched-chain fatty acid biosynthesis by catalyzing the decarboxylative condensation of malonyl-ACP with different acyl-coenzyme A (CoA) primers. This KASIII has one cysteine residue, which is critical for forming an acyl-enzyme intermediate in the first step of the process. Thre...

Enzymic activities and gene expression of oleoyl-CoA elongase were studied during seed development using two different rapeseed cultivars, high-erucic-acid rapeseed (HEAR) and low-erucic-acid rapeseed (LEAR). The overall elongase activities were maximal in HEAR between the fourth and eighth weeks after pollination (WAP) and absent in LEAR. The 3-ketoacyl-CoA synthase (condensing enzyme, CE) mRN...

The subunit locations of the five enzymes associated with the fatty acid oxidation complex from Escherichia coli were studied by immunotitration and chemical modification. Antibodies raised against the purified complex caused the parallel inhibitions of enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase, while slightly stimulating 3-ketoacyl-CoA thiolase. All five component enzymes of t...

Methyl-branched fatty acids and polyketides occur in a variety of living organisms. Previous studies have established that multifunctional enzymes use methylmalonyl coenzyme A (CoA) as the substrate to generate methyl-branched products such as mycocerosic acids and polyketides. However, we do not know which of the component activities show selectivity for methylmalonyl-CoA in any biological sys...

The DNA insert of plasmid pK52 contains the fadAB operon coding for the Escherichia coli fatty acid oxidation complex. Studies on the operon's structure and organization revealed that the initiator codon (ATG) of the structural gene for 3-ketoacyl-CoA thiolase, the fadA gene, is located 109 nucleotides 3' to the stop codon (TGA) of the fadB gene that encodes the alpha-subunit, a multifunctional...

The biosynthetic pathways of saturated and unsaturated fatty acids consist of many steps controlled by various enzymes. One of the methods for improving oil quality is to change the fatty acid profile through genetic manipulation which requires isolation and characterization of the genes and other cis-acting elements, such as the promoter, involved in fatty acid biosynthesis. b-ketoacyl-CoA syn...

Production of β-ketoacyl-CoA, which is catalyzed by 3-ketoacyl-CoA synthase (KCS), is the first step in very long chain fatty acid (VLCFA) biosynthesis. Here we identified 58 KCS genes from Gossypium hirsutum, 31 from G. arboreum and 33 from G. raimondii by searching the assembled cotton genomes. The gene family was divided into the plant-specific FAE1-type and the more general ELO-type. KCS tr...

In the biosynthesis of fatty acids, the beta-ketoacyl-acyl carrier protein (ACP) synthases catalyze chain elongation by the addition of two-carbon units derived from malonyl-ACP to an acyl group bound to either ACP or CoA. The crystal structure of beta-ketoacyl synthase II from Escherichia coli has been determined with the multiple isomorphous replacement method and refined at 2.4 A resolution....

Short-chain-length/medium-chain-length (SCL/MCL) polyhydroxyalkanoate (PHA) was produced in the plastids of Arabidopsis thaliana. Phe87Thr (F87T) mutated 3-ketoacyl-acyl carrier protein (ACP) synthase III (FabH) from Escherichia coli , and Ser325Thr/Gln481Lys (ST/QK) mutated polyhydroxyalkanoate (PHA) synthase (PhaC1) from Pseudomonas sp. 61-3, along with the beta-ketothiolase (PhaA) and acetoa...