Auxiliary enzyme of beta-oxidation. It participates in the metabolism of unsaturated fatty enoyl-CoA esters having double bonds in both even- and odd-numbered positions. Catalyzes the NADP-dependent reduction of 2,4-dienoyl-CoA to yield trans-3-enoyl-CoA.
Fatty acid catabolism by beta-oxidation mainly occurs in mitochondria and to a lesser degree in peroxisomes. Poly-unsaturated fatty acids are problematic for beta-oxidation, because the enzymes directly involved are unable to process all the different double bond conformations and combinations that occur naturally. In mammals, three accessory proteins circumvent this problem by catalyzing specific isomerization and reduction reactions. Central to this process is the NADPH-dependent 2,4-dienoyl-CoA reductase. We present high resolution crystal structures of human mitochondrial 2,4-dienoyl-CoA reductase in binary complex with cofactor, and the ternary complex with NADP(+) and substrate trans-2,trans-4-dienoyl-CoA at 2.1 and 1.75 A resolution, respectively. The enzyme, a homotetramer, is a short-chain dehydrogenase/reductase with a distinctive catalytic center. Close structural similarity between the binary and ternary complexes suggests an absence of large conformational changes during binding and processing of substrate. The site of catalysis is relatively open and placed beside a flexible loop thereby allowing the enzyme to accommodate and process a wide range of fatty acids. Seven single mutants were constructed, by site-directed mutagenesis, to investigate the function of selected residues in the active site thought likely to either contribute to the architecture of the active site or to catalysis. The mutant proteins were overexpressed, purified to homogeneity, and then characterized. The structural and kinetic data are consistent and support a mechanism that derives one reducing equivalent from the cofactor, and one from solvent. Key to the acquisition of a solvent-derived proton is the orientation of substrate and stabilization of a dienolate intermediate by Tyr-199, Asn-148, and the oxidized nicotinamide.
Interacting selectively and non-covalently with the reduced form, NADPH, of nicotinamide-adenine dinucleotide phosphate, a coenzyme involved in many redox and biosynthetic reactions.
Fatty acid catabolism by beta-oxidation mainly occurs in mitochondria and to a lesser degree in peroxisomes. Poly-unsaturated fatty acids are problematic for beta-oxidation, because the enzymes directly involved are unable to process all the different double bond conformations and combinations that occur naturally. In mammals, three accessory proteins circumvent this problem by catalyzing specific isomerization and reduction reactions. Central to this process is the NADPH-dependent 2,4-dienoyl-CoA reductase. We present high resolution crystal structures of human mitochondrial 2,4-dienoyl-CoA reductase in binary complex with cofactor, and the ternary complex with NADP(+) and substrate trans-2,trans-4-dienoyl-CoA at 2.1 and 1.75 A resolution, respectively. The enzyme, a homotetramer, is a short-chain dehydrogenase/reductase with a distinctive catalytic center. Close structural similarity between the binary and ternary complexes suggests an absence of large conformational changes during binding and processing of substrate. The site of catalysis is relatively open and placed beside a flexible loop thereby allowing the enzyme to accommodate and process a wide range of fatty acids. Seven single mutants were constructed, by site-directed mutagenesis, to investigate the function of selected residues in the active site thought likely to either contribute to the architecture of the active site or to catalysis. The mutant proteins were overexpressed, purified to homogeneity, and then characterized. The structural and kinetic data are consistent and support a mechanism that derives one reducing equivalent from the cofactor, and one from solvent. Key to the acquisition of a solvent-derived proton is the orientation of substrate and stabilization of a dienolate intermediate by Tyr-199, Asn-148, and the oxidized nicotinamide.
A fatty acid oxidation process that results in the complete oxidation of a long-chain fatty acid. Fatty acid beta-oxidation begins with the addition of coenzyme A to a fatty acid, and occurs by successive cycles of reactions during each of which the fatty acid is shortened by a two-carbon fragment removed as acetyl coenzyme A; the cycle continues until only two or three carbons remain (as acetyl-CoA or propionyl-CoA respectively).
Fatty acid catabolism by beta-oxidation mainly occurs in mitochondria and to a lesser degree in peroxisomes. Poly-unsaturated fatty acids are problematic for beta-oxidation, because the enzymes directly involved are unable to process all the different double bond conformations and combinations that occur naturally. In mammals, three accessory proteins circumvent this problem by catalyzing specific isomerization and reduction reactions. Central to this process is the NADPH-dependent 2,4-dienoyl-CoA reductase. We present high resolution crystal structures of human mitochondrial 2,4-dienoyl-CoA reductase in binary complex with cofactor, and the ternary complex with NADP(+) and substrate trans-2,trans-4-dienoyl-CoA at 2.1 and 1.75 A resolution, respectively. The enzyme, a homotetramer, is a short-chain dehydrogenase/reductase with a distinctive catalytic center. Close structural similarity between the binary and ternary complexes suggests an absence of large conformational changes during binding and processing of substrate. The site of catalysis is relatively open and placed beside a flexible loop thereby allowing the enzyme to accommodate and process a wide range of fatty acids. Seven single mutants were constructed, by site-directed mutagenesis, to investigate the function of selected residues in the active site thought likely to either contribute to the architecture of the active site or to catalysis. The mutant proteins were overexpressed, purified to homogeneity, and then characterized. The structural and kinetic data are consistent and support a mechanism that derives one reducing equivalent from the cofactor, and one from solvent. Key to the acquisition of a solvent-derived proton is the orientation of substrate and stabilization of a dienolate intermediate by Tyr-199, Asn-148, and the oxidized nicotinamide.
Fatty acid catabolism by beta-oxidation mainly occurs in mitochondria and to a lesser degree in peroxisomes. Poly-unsaturated fatty acids are problematic for beta-oxidation, because the enzymes directly involved are unable to process all the different double bond conformations and combinations that occur naturally. In mammals, three accessory proteins circumvent this problem by catalyzing specific isomerization and reduction reactions. Central to this process is the NADPH-dependent 2,4-dienoyl-CoA reductase. We present high resolution crystal structures of human mitochondrial 2,4-dienoyl-CoA reductase in binary complex with cofactor, and the ternary complex with NADP(+) and substrate trans-2,trans-4-dienoyl-CoA at 2.1 and 1.75 A resolution, respectively. The enzyme, a homotetramer, is a short-chain dehydrogenase/reductase with a distinctive catalytic center. Close structural similarity between the binary and ternary complexes suggests an absence of large conformational changes during binding and processing of substrate. The site of catalysis is relatively open and placed beside a flexible loop thereby allowing the enzyme to accommodate and process a wide range of fatty acids. Seven single mutants were constructed, by site-directed mutagenesis, to investigate the function of selected residues in the active site thought likely to either contribute to the architecture of the active site or to catalysis. The mutant proteins were overexpressed, purified to homogeneity, and then characterized. The structural and kinetic data are consistent and support a mechanism that derives one reducing equivalent from the cofactor, and one from solvent. Key to the acquisition of a solvent-derived proton is the orientation of substrate and stabilization of a dienolate intermediate by Tyr-199, Asn-148, and the oxidized nicotinamide.
Fatty acid catabolism by beta-oxidation mainly occurs in mitochondria and to a lesser degree in peroxisomes. Poly-unsaturated fatty acids are problematic for beta-oxidation, because the enzymes directly involved are unable to process all the different double bond conformations and combinations that occur naturally. In mammals, three accessory proteins circumvent this problem by catalyzing specific isomerization and reduction reactions. Central to this process is the NADPH-dependent 2,4-dienoyl-CoA reductase. We present high resolution crystal structures of human mitochondrial 2,4-dienoyl-CoA reductase in binary complex with cofactor, and the ternary complex with NADP(+) and substrate trans-2,trans-4-dienoyl-CoA at 2.1 and 1.75 A resolution, respectively. The enzyme, a homotetramer, is a short-chain dehydrogenase/reductase with a distinctive catalytic center. Close structural similarity between the binary and ternary complexes suggests an absence of large conformational changes during binding and processing of substrate. The site of catalysis is relatively open and placed beside a flexible loop thereby allowing the enzyme to accommodate and process a wide range of fatty acids. Seven single mutants were constructed, by site-directed mutagenesis, to investigate the function of selected residues in the active site thought likely to either contribute to the architecture of the active site or to catalysis. The mutant proteins were overexpressed, purified to homogeneity, and then characterized. The structural and kinetic data are consistent and support a mechanism that derives one reducing equivalent from the cofactor, and one from solvent. Key to the acquisition of a solvent-derived proton is the orientation of substrate and stabilization of a dienolate intermediate by Tyr-199, Asn-148, and the oxidized nicotinamide.
Protein involved in the biochemical reactions with fatty acids. Fatty acids are long chain organic acids of the general formula CH3(CnHx)COOH. They are constituents of lipids and can be saturated or unsaturated. The esterified forms are important both as energy storage molecules and structural molecules.
Protein involved in the biochemical reactions of lipids. Lipids are a diverse class of compounds which are insoluble in water but soluble in organic solvents. They include fats, oils, triacylglycerols, fatty acids, glycolipids, phospholipids and steroids.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.