Abstract
The Bateman domain of IMP dehydrogenase (IMPDH), a rate-limiting enzyme \r within the guanine nucleotide synthesis pathway, is a subdomain crucial in the regulatory \r moonlighting functions of the enzyme. In Escherichia coli during the stationary phase of \r growth, the IMPDH Bateman domain is readily acetylated on certain lysine amino acids, \r a modification that has no described effect on the enzyme or cellular metabolism. We \r report that acetylation of site K203 of the Bateman subdomain interferes with RNA \r polymerase interactions of IMPDH. In vivo deletion of the Bateman domain (guaBΔCBS) \r was found to have many of the same metabolic defects in the adenylate nucleotide \r biosynthesis pathway, caused by growth arrest by adenosine and inosine. We conclude \r that acetylation of the Bateman subdomain is involved in secondary functions of IMPDH \r such as protein pathway regulation and protein-protein interaction.