Catalyzes the hydrolytic deamination of enamine/imine intermediates that form during the course of normal metabolism. May facilitate the release of ammonia from these potentially toxic reactive metabolites, reducing their impact on cellular components. It may act on enamine/imine intermediates formed by several types of pyridoxal-5'-phosphate-dependent dehydratases including L-threonine dehydratase. May also function as an endoribonuclease, cleaving mRNA phosphodiester bonds of single-stranded RNA (By similarity). Thereby, may inhibit protein translation (PubMed:8973653).