Biosynthesis of chloramphenicol in Streptomyces species 3022a: the nature of the arylamine synthetase system

Abstract

The arylamine synthetase which catalyses the conversion of chorismic acid to p-aminophenylalanine in Streptomyces species 3022a was separated from aminotransferase by DEAE-cellulose chromatography. Recovered activity was stimulated by the addition of the aminotransferase and pyridoxal phosphate. Activity was further fragmented into three separate components by passage through a Sephadex G-100 column. Only one component produced p-aminophenylalanine but in combination the three stimulated each other's activity. Although the products of the other two components were unstable, an infrared spectrum of one of them was obtained and confirmed the presence of an aromatic amine, but other functional groups could not be ascertained. This product was not recognized as a substrate by the arylamine synthetase complex and it was suggested that it may be a degradation product of an intermediate of p-aminophenylalanine biosynthesis or an unknown intermediate of later biosynthetic steps of the chloramphenicol pathway. It is further suggested that arylamine compounds produced by this organism are the result of interaction of a core protein with other macromolecules and small molecular weight effector molecules.