ABSTRACT
In extracts of the unicellular cyanobacterium Gloeothece, the Fe-protein of nitrogenase can be separated by SDS-PAGE into two antigenically identifiable components. Unlike the situation in photosynthetic bacteria such as Rhodospirillum rubrum, these two forms do not arise from covalent modification of the protein by ADP-ribosylation. Rather, the Fe-protein of Gloeothece nitrogenase is subjected to modification by palmitoylation.
Subject(s)
Cyanobacteria/enzymology , Nitrogenase/chemistry , Nitrogenase/metabolism , Electrophoresis, Polyacrylamide Gel , Metalloproteins/chemistry , Metalloproteins/isolation & purification , Metalloproteins/metabolism , Nitrogenase/isolation & purification , Palmitic Acid/metabolism , Protein Processing, Post-TranslationalSubject(s)
ADP Ribose Transferases/metabolism , Cyanobacteria/enzymology , Glycoside Hydrolases/metabolism , N-Glycosyl Hydrolases , ADP Ribose Transferases/chemistry , ADP Ribose Transferases/isolation & purification , Cyanobacteria/growth & development , Darkness , Glycoside Hydrolases/chemistry , Glycoside Hydrolases/isolation & purification , Immunochemistry , Light , Molecular WeightABSTRACT
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.