title: A functional tomato ACC synthase expressed in Escherichia coli demonstrates suicidal inactivation by its substrate S-adenosylmethionine.
abstract: 1-Aminocyclopropane-1-carboxylate (ACC) synthase is a key enzyme in the biosynthesis of the plant hormone, ethylene. We have isolated, sequenced and expressed a functional tomato (cv Pik-Red) ACC synthase gene in Escherichia coli. ACC synthase expressed in E. coli was inactivated by incubation with S-adenosylmethionine (SAM), the half-time of which was concentration dependent. Mixing the tomato fruit protein extract with the cell-free extract from transformed E. coli did not affect SAM-dependent inactivation of ACC synthase activity. Thus, single isoforms of the ACC synthase enzyme, which demonstrate the biochemical features expected of the tomato fruit enzyme, can be expressed in E. coli and their structure-function relationships investigated.
authors.affiliation: Plant Molecular Biology Laboratory, Department of Agriculture/Agricultural Research Service, Beltsville Agricultural Research Center (W), MD 20705-2350.
authors.forename: N
authors.initials: N
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Wiesman
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: A K
authors.initials: AK
authors.lastname: Mattoo
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D004274:DNA, Recombinant; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D007700:Kinetics; D008190:Lyases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010944:Plants / Q000201:enzymology / Q000235:genetics; D012436:S-Adenosylmethionine / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D004274:DNA, Recombinant; D012436:S-Adenosylmethionine; D004247:DNA; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase