Catalyzes the addition and repair of the essential 3'-terminal CCA sequence in tRNAs without using a nucleic acid template. Adds these three nucleotides in the order of C, C, and A to the tRNA nucleotide-73, using CTP and ATP as substrates and producing inorganic pyrophosphate. Also shows phosphatase, 2'-nucleotidase and 2',3'-cyclic phosphodiesterase activities. These phosphohydrolase activities are probably involved in the repair of the tRNA 3'-CCA terminus degraded by intracellular RNases. a tRNA precursor + ATP + 2 CTP = a tRNA with a 3' CCA end + 3 diphosphate Magnesium is required for nucleotidyltransferase activity. Nickel for phosphatase activity. Monomer. Can also form homodimers and oligomers. Comprises two domains: an N-terminal domain containing the nucleotidyltransferase activity and a C-terminal HD domain associated with both phosphodiesterase and phosphatase activities. A single active site specifically recognizes both ATP and CTP and is responsible for their addition. Belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. Bacterial CCA-adding enzyme type 1 subfamily.