A class of antibacterials has been discovered that inhibits the growth of Gram-positive pathogenic bacteria. RWJ-49815, a representative of a family of hydrophobic tyramines, in addition to being a potent bactericidal Gram-positive antibacterial, inhibits the autophosphorylation of kinase A of the KinA::Spo0F two-component signal transduction system in vitro. Analogs of RWJ-49815 vary greatly in their ability to inhibit growth of bacteria and this ability correlates directly with their activity as kinase A inhibitors. Compared with the potent quinolone, ciprofloxacin, RWJ-49815 exhibits reduced resistance emergence in a laboratory passage experiment. Inhibition of the histidine protein kinase::response regulator two-component signal transduction pathways may present an opportunity to depress chromosomal resistance emergence by targeting multiple proteins with a single inhibitor in a single bacterium. Such inhibitors may represent a class of antibacterials that potentially may represent a breakthrough in antibacterial therapy.