Mycobacterial targets of pyrazinoic acid (POA targets)

Pyrazinoic acid (POA) is the active metabolite of the prodrug pyrazinamide (PZA), a cornerstone of modern tuberculosis (TB) treatment that is essential for shortening the duration of therapy (Zhang et al., 2003). POA is uniquely effective against semi-dormant or "persister" populations of Mycobacterium tuberculosis residing in acidic environments, such as those found within phagosomes or necrotic lesions (Zhang et al., 2014). Its antibacterial effects are mediated through a multi-targeted mechanism, primarily involving the inhibition of ribosomal protein S1 (RpsA) and aspartate 1-decarboxylase (PanD). By binding to RpsA, POA interferes with trans-translation, a process vital for clearing stalled ribosomes and maintaining protein synthesis quality control (Shi et al., 2011). Its interaction with PanD disrupts the biosynthesis of Coenzyme A, a critical metabolic cofactor (Zhang et al., 2014). Additionally, POA acts as a weak acid ionophore, acidifying the cytoplasm and collapsing the proton motive force, which leads to a depletion of cellular energy in non-replicating bacilli (Zhang et al., 2003).

Other names

Pyrazinamide targetsPOA-binding proteinsRibosomal protein S1 (RpsA)Aspartate 1-decarboxylase (PanD)Fatty acid synthase I (FAS-I)PanZ (Rv3601c)

Inhibition of trans-translation via RpsA binding, inhibition of Coenzyme A biosynthesis via PanD binding, and disruption of membrane potential and pH homeostasis.