Enzymatic and genetic characterization of firefly luciferase and Drosophila CG6178 as a fatty acyl-CoA synthetase.
Recently we found that firefly luciferase is a bifunctional enzyme, catalyzing not only the luminescence reaction but also long-chain fatty acyl-CoA synthesis. Further, the gene product of CG6178 (CG6178), an ortholog of firefly luciferase in Drosophila melanogaster, was found to be a long-chain fatty acyl-CoA synthetase and dose not function as a luciferase. We investigated the substrate specificities of firefly luciferase and CG6178 as an acyl-CoA synthetase utilizing a series of carboxylic acids. The results indicate that these enzymes synthesize acyl-CoA efficiently from various saturated medium-chain fatty acids. Lauric acid is the most suitable substrate for these enzymes, and the product of lauroyl CoA was identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Phylogenetic analysis indicated that firefly luciferase and CG6178 genes belong to the group of plant 4-coumarate:CoA ligases, and not to the group of medium- and long-chain fatty acyl-CoA synthetases in mammals. These results suggest that insects have a novel type of fatty acyl-CoA synthetase.
Oba
Yuichi
Y
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan. oba@agr.nagoya-u.ac.jp
Sato
Mitsunori
M
Ojika
Makoto
M
Inouye
Satoshi
S
D000214:Acyl Coenzyme A / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002264:Carboxylic Acids / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000235:genetics* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics*; D007850:Lauric Acids / Q000378:metabolism; D049409:Luciferases, Firefly / Q000235:genetics* / Q000378:metabolism*; D015394:Molecular Structure; D010802:Phylogeny; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity
D000214:Acyl Coenzyme A; D002264:Carboxylic Acids; D029721:Drosophila Proteins; D007850:Lauric Acids; C030358:lauric acid; C050466:lauroyl-coenzyme A; D049409:Luciferases, Firefly; D003066:Coenzyme A Ligases; C488249:CG6178 protein, Drosophila