The Escherichia coli NadR regulator is endowed with nicotinamide mononucleotide adenylyltransferase activity

Abstract

The first identification and characterization of a catalytic activity associated with NadR protein is reported. A computer-aided search for sequence similarity revealed the presence in NadR of a 29-residue region highly conserved among known nicotinamide mononucleotide adenylyltransferases. The Escherichia coli nadR gene was cloned into a T7- based vector and overexpressed. In addition to functionally specific DNA binding properties, the homogeneous recombinant protein catalyzes NAD synthesis from nicotinamide mononucleotide and ATP.