Borrelia burgdorferi’s inosine-5′-monophosphate dehydrogenase (IMPDH, GuaB encoded by the guaB gene) is a critical enzyme that catalyzes the limiting, NAD-mediated interconversion of inosine-5′-monophosphate (IMP) to xanthosine-5′-monophosphate (XMP). Xanthosine-5′-monophosphate is then convert...