Analysis of Escherichia coli nicotinate mononucleotide adenylyltransferase mutants in vivo and in vitro

The mutations in the C-terminus did not reveal any function for the conserved motif. On the other hand, our data has lead us to assign amino acid residues His-19, Arg-46 and Asp-109 to the active site. We have also shown that the nadD gene is essential for growth in E. coli.