The Bare Essentials of Antibiotic Target Validation

The convergence of competitive fitness experiments and phenotypic screening would seem to be an auspicious beginning for validation of an antibacterial target. IMPDH was already identified an essential protein in Mycobacterium tuberculosis when not one, but two, groups discovered inhibitors with promising antitubercular activity. A new target appeared to be born. Surprisingly, the two groups come to completely different conclusions about the vulnerability of IMPDH and its future as a drug target. This Viewpoint discusses these papers and how to resolve this conundrum.