Component of the EKC/KEOPS complex that is required for the formation of a threonylcarbamoyl group on adenosine at position 37 (t(6)A37) in tRNAs that read codons beginning with adenine. The complex is probably involved in the transfer of the threonylcarbamoyl moiety of threonylcarbamoyl-AMP (TC-AMP) to the N6 group of A37. Bud32 has ATPase activity in the context of the EKC/KEOPS complex and likely plays a supporting role to the catalytic subunit osgep (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Component of the EKC/KEOPS complex; the whole complex dimerizes. This protein is considered an atypical serine/threonine kinase, because it lacks the conventional structural elements necessary for the substrate recognition as well as a lysine residue that in all other serine/threonine kinases participates in the catalytic event. Bud32 has protein kinase activity in vitro, but in the context of the EKC/KEOPS complex, the catalytic subunit osgep switches the activity of bud32 from kinase into ATPase (By similarity). Belongs to the protein kinase superfamily. BUD32 family.