Members of this protein family are the bacterial polynucleotide kinase-phosphatase (Pnkp) whose genes occur paired with genes for the 3' terminal RNA ribose 2'-O-methyltransferase Hen1. All members of the seed alignment belong to a cassette with the Hen1. The pair acts in bacterial RNA repair. This enzyme performs end-healing reactions on broken RNA, preparing from the RNA ligase to close the break. The working hypothesis is that the combination of Pnkp (RNA repair) and Hen1 (RNA modification) serves to first repair RNA damage from ribotoxins and then perform a modification that prevents the damage from recurring. [Transcription, RNA processing]
Jiyao W et al.(2023). "The conserved domain database in 2023.",