3.1.4.16 - 3.1.4.16 from the spent culture medium of phosphate-starved cells, 15fold 3.1.4.16 Ni-NTA agarose column chromatography 3.1.4.16 partial 3.1.4.16 partial, activity towards 2',3'-cyclic nucleotides and 3',5'-cyclic nucleotides are associated with the same protein molecule 3.1.4.16 Talon affinity column chromatography