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 probably involved in the transfer of the threonylcarbamoyl moiety of threonylcarbamoyl-AMP (TC-AMP) to the N6 group of A37, together with TsaD and TsaB. 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. kcat is 0.0026 sec(-1) for ATP hydrolysis. Homodimer. Interacts with TsaB. Appears essential for growth, since no null mutants can be obtained. Conditional depletion of this gene leads to very elongated cells, 1.5 to 1.75 times wider than wild-type, displaying an unusual distribution of the DNA, which appears to be located around the periphery of the cell rather than throughout the cytoplasm. The TsaE depletion phenotype is suppressed by overexpressing the response regulator RstA. TsaBCDE are necessary and sufficient for tRNA(NNU) t(6)A37 threonylcarbamoyladenosine modification in vitro in E.coli. 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 E.coli 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.