Enables protein N-terminus binding activity. Predicted to be involved in several processes, including protein ADP-ribosylation; protein localization to chromosome, telomeric region; and regulation of telomere maintenance. Predicted to act upstream of or within regulation of growth. Predicted to be located in nuclear envelope; pericentriolar material; and perinuclear region of cytoplasm. Predicted to be active in cytoplasm and nucleus. Orthologous to human TNKS2 (tankyrase 2). [provided by Alliance of Genome Resources, Apr 2022]