The emergence of multidrug-resistant pathogens necessitates the search for new antibiotics acting on previously unexplored targets. Nicotinate mononucleotide adenylyltransferase of the NadD family, an essential enzyme of NAD biosynthesis in most bacteria, was selected as a target for structure-based inhibitor development. To this end, the inventors have identified small molecule compounds that inhibit bacterial target enzymes by interacting with a novel inhibitory binding site on the enzyme while having no effect on functionally equivalent human enzymes.