Antibiotic that interferes with DNA function is:

Mechanism of Action Metronidazole is a prodrug requiring reductive activation of the nitro group by susceptible organisms.  Unlike their aerobic counterparts, anaerobic and microaerophilic pathogens contain electron transport components that have a sufficiently negative redox potential to donate electrons to metronidazole.  The single-electron transfer forms a highly reactive nitro radical anion that kills susceptible organisms by radical-mediated mechanisms that target DNA. Reference: Goodman & Gilman’s THE PHARMACOLOGICAL BASIS OF THERAPEUTICS THIRTEENTH EDITION Page no 991