Component of the pyruvate dehydrogenase (PDH) complex, that catalyzes the overall conversion of pyruvate to acetyl-CoA and CO(2). Together with AhpC, AhpD and Lpd, constitutes an NADH-dependent peroxidase active against hydrogen and alkyl peroxides as well as serving as a peroxynitrite reductase, thus protecting the bacterium against reactive nitrogen intermediates and oxidative stress generated by the host immune system. Appears to be essential for Mtb pathogenesis. (R)-N(6)-dihydrolipoyl-L-lysyl-[protein] + acetyl-CoA = (R)-N(6)-(S(8)-acetyldihydrolipoyl)-L-lysyl-[protein] + CoA Binds 2 lipoyl cofactors covalently. Inhibited by rhodanine compounds. Some of them almost exclusively kill non-replicating mycobacteria in synergy with products of host immunity, such as nitric oxide and hypoxia, and are effective on bacteria within macrophages. Optimum pH is 8.0 for PDH complex activity. Half-maximal activity is observed at pH 7.0 and pH 9.0. Activity is abolished at pH < 5. Forms a 24-polypeptide structural core with octahedral symmetry (By similarity). Identified in a complex with AhpC, AhpD and Lpd. Part of the PDH complex, consisting of multiple copies of AceE (E1), DlaT (E2) and Lpd (E3). Cells lacking this gene show severely retarded growth in vitro, and display no PDH activity. They are also more sensitive to nitrosative stress caused by NaNO(2), and to macrophage-induced killing in vitro. They also show at least 20-fold reduction in survival in a mouse tuberculosis model, and are unable to cause disease in a guinea pig model of tuberculosis infection. Disruption of dlaT leads to high up-regulation of the expression of the bkdABC operon. Is the only lipoylated protein in strain H37Rv grown on a standard rich medium. However, in a DlaT-deficient strain, another protein, BkdC, becomes lipoylated. Belongs to the 2-oxoacid dehydrogenase family.