Activates the tRNA-splicing ligase complex by facilitating the enzymatic turnover of catalytic subunit RtcB. Acts by promoting the guanylylation of RtcB, a key intermediate step in tRNA ligation. Can also alter the NTP specificity of RtcB such that ATP, dGTP or ITP is used efficiently (By similarity). Chaperone or modulator of proteins involved in DNA or RNA processing. Protects the tRNA (cytosine-5-)-methyltransferase PAB1947 against aggregation and increases its specificity. In solution, exists as a monomer, trimer and hexamer. Oligomeric states form a tripartite complex with tRNA and PAB1947 methyltransferase. Belongs to the archease family.