Novobiocin primarily targets ParE in Neisseria gonorrhoeae.

Multidrug-resistant Neisseria gonorrhoeae is a pathogenic bacterium that poses a public health concern. In this study, we aimed to elucidate the mode of action of the conventional antibiotic novobiocin, which has been selected as a leading compound for novel antigonococcal drugs. Unlike other previously studied bacteria strains, novobiocin-resistant N. gonorrhoeae strains have a mutation in the parE gene encoding DNA topoisomerase IV, strongly implying that the primary target of novobiocin is DNA topoisomerase IV and not DNA gyrase. The construction of genetically modified strains and structural biology analysis in silico suggest that this target discrepancy is from variations in the amino acid sequences in GyrB (Ile 78 in Escherichia coli, Met82 in N. gonorrhoeae) and ParE (Met 74 in E. coli, Ile76 in N. gonorrhoeae). This finding contributes to the development of drugs that target both GyrB and ParE enzymes to a similar extent.