Cell wall damage caused by AG can perturb the membrane integrity thereby affecting respiratory chain, redox balance, and ATP generation. All of this results in metabolic instability and AG-induced killing. To tolerate AG, Mtb redirects respiration from the energetically efficient route (e.g. NDH1, CyBC1) to the energetically poor one (e.g. NDH2, CyBD), and carbon metabolism from the TCA cycle to glyoxylate, glycolysis and gluconeogenesis. Rerouting of electron flux through CyBD can trigger generation of ROS (O2−• and H2O2) by univalent reduction of O2 via metal-, flavin-, and quinone-containing respiratory enzymes. The intramycobacterial redox buffer, MSH, detoxifies ROS to protect Mtb from AG. The oxidative shift in EMSH of Mtb in response to AG serves as a cue to calibrate the expression of β-lactamase, PG enzymes, carbon metabolism, antioxidants, and alternate respiration via WhiB4. Under native conditions, O2-induced loss of WhiB4 Fe-S cluster generates oxidized apo-WhiB4, which binds and represses the expression of blaR and blaC. Reduction of oxidized apo-WhiB4 disulfides reversed this effect. Down-regulation of whiB4 in response to AG derepresses blaR and stimulates expression of blaC directly and/or indirectly via BlaR-mediated cleavage of the blaC repressor (i.e. BlaI) to induce AG tolerance. Accumulation of oxidized apo-WhiB4 upon overexpression led to hyper-repression of BlaC activity and oxidative shift in EMSH to potentiate mycobactericidal activity of AG. Since genes associated with alternate-respiration (e.g. CyBD) and energy metabolism (e.g. ATP synthase) are also regulated by BlaI, our results suggest cross-talk between WhiB4 and BlaI pathways resulting in AG tolerance of Mtb. Altogether, WhiB4 couples the changes in the redox physiology of Mtb triggered by AG to the expression of genes involved in antibiotic tolerance and redox homeostasis. MA: Mycolic acid, CM: Cytoplasmic membrane, NDH1: NADH-dehydrogenase I (nuo operon), NDH2: NADH dehydrogenase 2 (ndh), CyBD: Cytochrome BD oxidase, CyBC1: Cytochrome BC1-aa3 oxidase, F0F1 ATP syn: ATP Synthase, PBP: Penicillin-binding proteins and SDH: Succinate Dehydrogenase. Bold or dashed arrows indicate increased or decreased electron flow through respiratory complexes, respectively, based on gene expression data.