Required for the formation of a threonylcarbamoyl group on adenosine at position 37 (t(6)A37) in tRNAs that read codons beginning with adenine. Is involved in the transfer of the threonylcarbamoyl moiety of threonylcarbamoyl-AMP (TC-AMP) to the N6 group of A37, together with TsaD and TsaB; this reaction does not require ATP in vitro. TsaE seems to play an indirect role in the t(6)A biosynthesis pathway, possibly in regulating the core enzymatic function of TsaD. Displays ATPase activity in vitro, which is modulated by the oligomeric status of the protein. Values are given for the monomeric form. The rate of ATP hydrolysis is about three times higher for the monomeric form as compared to the homooligomeric forms. Monomer, homodimer or homotetramer; in equilibrium. Low salt concentration favors oligomerization, while high salt concentration favors the monomeric form. Localized predominantly at the cell poles and at the periphery of the bacterium. Expressed at all stages of growth. Cells lacking this gene exhibit significantly reduced growth in rich and minimal medium. The four proteins YwlC, TsaD, TsaB and TsaE are necessary and sufficient for tRNA(NNU) t(6)A37 threonylcarbamoyladenosine biosynthesis in vitro in B.subtilis. Belongs to the TsaE family. The well-known t(6)A modification appears to be a hydrolyzed artifact of natural cyclic t(6)A (ct(6)A) that occurs during the preparation and handling of tRNA in B.subtilis and many other species (PubMed:23242255). In these species, the t(6)A modification is processed further by dehydration into ct(6)A, a reaction catalyzed by TcdA.