Molecular characterization of lantibiotic-synthesizing enzyme EpiD revealsa function for bacterial Dfp proteins in coenzyme A biosynthesis

The lantibiotic-synthesizing flavoprotein EpiD catalyzes the oxidative deca rboxylation of peptidylcysteines to peptidyl-aminoenethiols. The sequence m otif responsible for flavin coenzyme binding and enzyme activity is conserv ed in different proteins from all kingdoms of life. Dfp proteins of eubacte ria and archaebacteria and salt tolerance proteins of yeasts and plants bel ong to this new family of flavoproteins. The enzymatic function of all thes e proteins was not known, but our experiments suggested that they catalyze a similar reaction like EpiD and/or may have similar substrates and are hom ododecameric flavoproteins. We demonstrate that the N-terminal domain of th e Escherichia coli Dfp protein catalyzes the decarboxylation of (R)-4'-phos pho-N-pantothenoylcysteine to 4'-phosphopantetheine. This reaction is essen tial for coenzyme A biosynthesis.