Exoribonuclease that catalyzes the last steps of 5S, 16S and 23S rRNA 5'-end maturation. Removes 3 nucleotides (nt) from the 5' end of 5S, 16S and 23S rRNA precursors to generate the mature 5' ends. 5S and 23S rRNA maturation occurs more efficiently and accurately on ribosomal particles as compared to free RNA. Efficiently catalyzes the hydrolysis of the 3'-phosphate from 3',5'-bis-phosphonucleotides as well as the successive hydrolysis of 5'-phosphomononucleotides from the 5'-end of short pieces of RNA and DNA, with no specificity toward the identity of the nucleotide base. Is more efficient at hydrolyzing RNA oligonucleotides than DNA oligonucleotides. This enzyme can also hydrolyze annealed DNA duplexes, albeit at a catalytic efficiency lower than that of the corresponding single-stranded oligonucleotides. a ribonucleoside 3',5'-bisphosphate + H2O = a ribonucleoside 5'-phosphate + phosphate Belongs to the PHP family. TrpH/YciV subfamily. Truncated N-terminus.