Biosynthesis of the tropane-related cyanobacterial toxin anatoxin-a: role of ornithine decarboxylase.
A study was made of the biosynthesis by Anabaena flos-aquae of the tropane-related alkaloid anatoxin-a. Evidence is presented that the toxin arises from ornithine via putrescine (1,4-diaminobutane) and that ornithine decarboxylase (EC 4.1.1.17) is involved. An ornithine decarboxylase preparation, with optimal activity at pH 8, was obtained from Anabaena flos-aquae and partially purified by gel-filtration chromatography on DEAE-cellulose. One major and one minor peak of enzymic activity were obtained with Km values of 1.25 and 2.5 mM, respectively. Plasmid DNA (10 Kb; Mr 6.5 x 10(6] was detected in the toxic strain of Anabaena flos-aquae but not in a non-toxic strain. DNA from the toxin-producing strain of Anabaena flos-aquae transforms the non-toxic into a toxic strain.
Department of Biochemistry, University College of Swansea, Singleton Park, U.K.
J R
JR
Gallon
K N
KN
Chit
E G
EG
Brown
D002848:Chromatography, DEAE-Cellulose; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D008387:Marine Toxins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D009955:Ornithine Decarboxylase / Q000302:isolation & purification / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D014170:Transformation, Genetic
D008387:Marine Toxins; D009955:Ornithine Decarboxylase