Biosynthesis of Ubiquinone in Escherichia coli K-12: Biochemical and Genetic Characterization of a Mutant Unable to Convert Chorismate into 4-Hydroxybenzoate

摘要

A mutant strain of Escherichia coli unable to carry out the first specific reaction of ubiquinone biosynthesis, that is the conversion of chorismate into 4-hydroxybenzoate, has been isolated. The gene concerned maps at about minute 79 on the E. coli chromosome and has been designated ubiC. This gene is probably the structural gene for chorismate lyase since cell extracts from a transductant strain carrying the ubiC437 mutant allele are unable to convert chorismate into 4-hydroxybenzoate and growing cells of the mutant do not form appreciable quantities of ubiquinone unless 4-hydroxybenzoate is added to the growth medium.