Identification of yacE ( coaE ) as the Structural Gene for Dephosphocoenzyme A Kinase in Escherichia coli K-12

Abstract

ABSTRACT Dephosphocoenzyme A (dephospho-CoA) kinase catalyzes the final step in coenzyme A biosynthesis, the phosphorylation of the 3′-hydroxy group of the ribose sugar moiety. Wild-type dephospho-CoA kinase from Corynebacterium ammoniagenes was purified to homogeneity and subjected to N-terminal sequence analysis. A BLAST search identified a gene from Escherichia coli previously designated yacE encoding a highly homologous protein. Amplification of the gene and overexpression yielded recombinant dephospho-CoA kinase as a 22.6-kDa monomer. Enzyme assay and nuclear magnetic resonance analyses of the product demonstrated that the recombinant enzyme is indeed dephospho-CoA kinase. The activities with adenosine, AMP, and adenosine phosphosulfate were 4 to 8% of the activity with dephospho-CoA. Homologues of the E. coli dephospho-CoA kinase were identified in a diverse range of organisms.