6-Hydroxymellein synthetase as a multifunctional enzyme complex in elicitor-treated carrot root extract.
Synthetic activity of a polyketide compound 6-hydroxymellein was induced in elicitor-treated carrot root tissues. The activity was significantly inhibited by an antiserum raised against the acyl carrier protein (ACP) of fatty acid synthetase, suggesting that the enzyme(s) for 6-hydroxymellein synthesis require(s) a functional unit similar to ACP. However, the synthetic activity was not stimulated by the addition of ACP purified from Escherichia coli and was not lost even after fractionation by gel-filtration chromatography. The active fraction obtained by gel-filtration (136 kDa) was subjected to immunoblot analysis, and a 128 kDa polypeptide in the fraction was found to cross-react with anti-ACP serum. These observations suggest that the biosynthesis of 6-hydroxymellein in carrot cells is catalyzed by an enzyme consisting of a single peptide chain.
Kurosaki
F
F
Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Itoh
M
M
Yamada
M
M
Nishi
A
A
D000213:Acyl Carrier Protein / Q000378:metabolism; D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002850:Chromatography, Gel; D003374:Coumarins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D003429:Cross Reactions; D004926:Escherichia coli / Q000201:enzymology; D064429:Fatty Acid Synthases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015151:Immunoblotting; D049934:Isocoumarins; D008025:Ligases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*
D000213:Acyl Carrier Protein; D003374:Coumarins; D049934:Isocoumarins; D009097:Multienzyme Complexes; C070622:6-hydroxymellein; D010088:Oxidoreductases; D000217:Acyltransferases; D064429:Fatty Acid Synthases; C070623:6-hydroxymellein synthetase; D008025:Ligases