The member of this family from Deinococcus radiodurans, a species that withstands and recovers from extensive radiation or dessication damage, is an apparent RNA ligase. It repairs RNA stand breaks in nicked DNA:RNA and RNA:RNA but not DNA:DNA duplexes. It has adenylyltransferase activity associated with the C-terminal domain. Related proteins also in this family are found in Streptomyces avermitilis MA-4680 and in bacteriophage 44RR2.8t. The phage example is unsurprising since one mechanism of host cell defense against phage is cleavage and inactivation of certain tRNA molecules. A fungal sequence from Neurospora crassa scores between trusted and noise cutofffs and may be similar in function.
Jiyao W et al.(2023). "The conserved domain database in 2023.",