Identification of yacE (coaE) as the structural gene for dephosphocoenzymea kinase in Escherichia coli K-12

Dephosphocoenzyme A (dephospho-CoA) kinase catalyzes the final step in coen zyme A biosynthesis, the phosphorylation of the 3'-hydroxy group of the rib ose sugar moiety. Wild-type dephospho-CoA kinase from Corynebacterium ammon iagenes was purified to homogeneity and subjected to N-terminal sequence an alysis. A BLAST search identified a gene from Escherichia coli previously d esignated yacE encoding a highly homologous protein. Amplification of the g ene and overexpression yielded recombinant dephospha-CoA kinase as a 22.6-k Da monomer. Enzyme assay and nuclear magnetic resonance analyses of the pro duct demonstrated that the recombinant enzyme is indeed dephospho-CoA kinas e. The activities with adenosine, AMP, and adenosine phosphosulfate were 4 to 8% of the activity with dephospho-CoA. Homologues of the E. coli dephosp ho-CoA kinase were identified in a diverse range of organisms.