Involved in the synthesis of both phthiocerol dimycocerosates (PDIMs) and phenolic glycolipids (PGLs), which are structurally related lipids non-covalently bound to the outer cell wall layer of M.tuberculosis and are important virulence factors (PubMed:30292819). In vitro, TesA has both thioesterase and esterase activities (PubMed:30292819, PubMed:31388991). Exhibits thioesterase activity on acyl-CoA derivatives such as palmitoyl-CoA and decanoyl-CoA (PubMed:30292819, PubMed:31388991). Also displays hydrolytic activity on ester substrates, being more active on pNP esters with short carbon chain lengths (C2-C5) than with those bearing medium and long carbon chain lengths (C8-C18) (PubMed:30292819). a fatty acyl-CoA + H2O = a fatty acid + CoA + H(+) H2O + hexadecanoyl-CoA = CoA + H(+) + hexadecanoate decanoyl-CoA + H2O = CoA + decanoate + H(+) an acetyl ester + H2O = acetate + an aliphatic alcohol + H(+) H2O + pentanoate ester = an aliphatic alcohol + H(+) + pentanoate an octanoate ester + H2O = an aliphatic alcohol + H(+) + octanoate Strongly inhibited in vitro by CyC17, a monocyclic enol phosphate analog to Cyclipostins, which binds covalently to the catalytic Ser-104 residue leading to a total loss of enzyme activity (PubMed:30292819). Methyl arachidonyl fluorophosphonate (MAFP) inhibits esterase activity but it only reduces by approximately 50% thioesterase activity with palmitoyl-CoA as substrate (PubMed:31388991). Thioesterase activity is inhibited by tetrahydrolipstatin (THL) (PubMed:31388991). kcat is 0.00342 sec(-1) with palmitoyl-CoA as substrate. Optimum temperature is 37 degrees Celsius (with palmitoyl-CoA as substrate). Monomer. Can form homodimers in the presence of palmitoyl-CoA (PubMed:31388991). Interacts with the C-terminal region of PpsE (PubMed:15668773). Belongs to the thioesterase family.