Actinomycin synthesis in Streptomyces antibioticus. Purification and properties of a 3-hydroxyanthranilate 4-methyltransferase.

摘要: A methyltransferase, which utilizes 3-hydroxyanthranilic acid (HAA) as a substrate, has been purified to near homogeneity from 30-36-h mycelium of the bacterium Streptomyces antibioticus. The enzyme was obtained in approximately 20% yield with purification 130-fold. Polyacrylamide gel electrophoresis under denaturing conditions indicates that is composed single subunit Mr about 36,000. On chromatography 0.5 M NaCl, displays molecular weight 37,000. specific activity S. antibioticus maximal between 30 and 36 h following inoculation galactose/glutamic medium and, at those times post-inoculation, essentially same extracts cultures grown on glucose rather than galactose carbon source. stimulated by Na2EDTA (in crude extracts) 2-mercaptoethanol methyltransferase shows strong preference for HAA substrate compared number analogs. Thin layer ethyl acetate large-scale incubation mixtures confirms product reaction 4-methyl-3-hydroxyanthranilic acid. also phenoxazinone synthase incorporated into actinomycin mycelium. Kinetic parameters determined.