proteins having nucleic acids as prosthetic groups, and thus yielding nucleic acids (or their cleavage products) as well as amino acids on hydrolytic cleavage.
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1352 (https://doi.org/10.1351/pac199567081307)