Phosphodiesterase Activity of Ec DOS, a Heme-regulated Enzyme from Escherichia coli, toward 3′,5′-Cyclic Diguanylic Acid Is Obviously Enhanced by O2 and CO Binding

Abstract

Abstract 3′,5′-Cyclic diguanylic acid (c-di-GMP) is emerging as an important bacterial intracellular signaling molecule. Both the Fe(III) and Fe(II) heme complexes of Ec DOS, a heme-bound PAS sensor enzyme from Escherichia coli, have phosphodiesterase activity toward c-di-GMP (27 and 61 min−1, respectively) and that the activity of the Fe(II) heme complex is obviously enhanced by the binding of either O2 (126 min−1) or CO (143 min−1). Therefore, Ec DOS appears to be a novel type of gas sensor enzyme.