Coenzyme F ₄₂₀ -Dependent Glucose-6-Phosphate Dehydrogenase-Coupled Polyglutamylation of Coenzyme F ₄₂₀ in Mycobacteria

Coenzyme F 420 -dependent reactions of Mycobacterium tuberculosis , which causes tuberculosis, potentially contributes to the virulence of this bacterium. The coenzyme carries a glutamic acid-derived tail, the length of which influences the metabolism of M. tuberculosis . Mutations that eliminate the production of F 420 with longer tails make M. tuberculosis resistant to two new tuberculosis drugs. This report describes that the synthesis of longer glutamyl tails of F 420 requires concerted actions of two enzymes, one of which reduces the coenzyme prior to the action of the other, which catalyzes polyglutamylation. This knowledge will help to develop more effective tuberculosis (TB) drugs. Remarkably, the introduction of multiple glutamate residues into the sidechain of folate (vitamin B 9 ) requires similar concerted actions, where one enzyme reduces the vitamin to tetrahydrofolate and the other catalyzes polyglutamylation; folate is required for DNA and amino acid synthesis. Thus, the reported research has also revealed a key similarity between two important cellular systems.