title: Adenylosuccinate synthetase: site of action of hydantocidin, a microbial phytotoxin.
abstract: The site of action of hydantocidin was probed using Arabidopsis thaliana plants growing on agar plates. Herbicidal effects were reversed when the agar medium was supplemented with AMP, but not IMP or GMP, suggesting that hydantocidin blocked the two-step conversion of IMP to AMP in the de novo purine biosynthesis pathway. Hydantocidin itself did not inhibit adenylosuccinate synthetase or adenylosuccinate lyase isolated from Zea mays. However, a phosphorylated derivative of hydantocidin, N-acetyl-5'-phosphohydantocidin, was a potent inhibitor of the synthetase but not of the lyase. These results identify the site of action of hydantocidin and establish adenylosuccinate synthetase as an herbicide target of commercial potential.
authors.affiliation: Sandoz Agro, Inc., Research Division, Palo Alto, California 94304-1104, USA. siehl@sandoz.com
authors.forename: D L
authors.initials: DL
authors.lastname: Siehl
authors.forename: M V
authors.initials: MV
authors.lastname: Subramanian
authors.forename: E W
authors.initials: EW
authors.lastname: Walters
authors.forename: S F
authors.initials: SF
authors.lastname: Lee
authors.forename: R J
authors.initials: RJ
authors.lastname: Anderson
authors.forename: A G
authors.initials: AG
authors.lastname: Toschi
mesh_terms: D000249:Adenosine Monophosphate / Q000096:biosynthesis; D000264:Adenylosuccinate Lyase / Q000187:drug effects; D000265:Adenylosuccinate Synthase / Q000187:drug effects*; D000931:Antidotes; D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology*; D006827:Hydantoins / Q000737:chemistry / Q000494:pharmacology*; D007291:Inosine Monophosphate / Q000378:metabolism; D010428:Pentosephosphates / Q000494:pharmacology*; D003313:Zea mays / Q000201:enzymology
chemical_list: D000931:Antidotes; D004791:Enzyme Inhibitors; D006540:Herbicides; D006827:Hydantoins; C098603:N-acetyl-5'-phosphohydantocidin; D010428:Pentosephosphates; C068815:hydantocidin; D007291:Inosine Monophosphate; D000249:Adenosine Monophosphate; C001321:hadacidin; D000264:Adenylosuccinate Lyase; D000265:Adenylosuccinate Synthase; D005998:Glycine