Biosynthesis of o-succinylbenzoic acid. II: Properties of o-succinylbenzoic acid synthase, an enzyme involved in vitamin K2 biosynthesis.

The enzyme system (OSB2 synthase) catalyzing the synthesis of o-succinylbenzoic acid from isochorismic acid and alpha-ketoglutaric acid in the presence of thiamine pyrophosphate was isolated from Escherichia coli AN 154 and characterized. The purification factor of the enzyme did not increase during column chromatography on Sephadex G-200 or chromatofocusing, suggesting that the OSB synthase is labile. Chromatography on DEAE-Sephadex A-50 or A-25 showed that an enzyme activity separated from fractions containing OSB synthase that decarboxylates alpha-ketoglutarate.

Biosynthesis of o-succinylbenzoic acid. I: Cell free synthesis of o-succinylbenzoic acid from isochorismic acid in enzyme preparations from vitamin K producing bacteria.

Escherichia coli K12 and a mutant of E. coli (viz., AN 154) as well as Aerobacter aerogenes 62-1 (i.