Bifunctional enzyme which has both oligoribonuclease and pAp-phosphatase activities. Degrades short RNA and DNA oligonucleotides with a length of up to 33 nucleotides, although the enzyme is most active on shorter substrates, in a 5' to 3' direction. Converts 3'(2')-phosphoadenosine 5'-phosphate (PAP) to AMP, has very low activity on cAMP and cGMP. adenosine 3',5'-bisphosphate + H2O = AMP + phosphate Requires a divalent cation; Co(2+) > Mn(2+) >Zn(2+) > Mg(2+). kcat for ss nucleic acids decreases about 5 orders of magnitude as chain length increases from 3-mers to 21-mers. Oligomeric. Reduced growth in minimal medium, possibly also affected in cysteine assimilation. Belongs to the NrnA oligoribonuclease family.