RNA exonuclease that binds to the 3'-end of histone mRNAs and degrades them, suggesting that it plays an essential role in histone mRNA decay after replication (PubMed:14536070, PubMed:16912046, PubMed:17135487, PubMed:37352860). A 2' and 3'-hydroxyl groups at the last nucleotide of the histone 3'-end is required for efficient 3'-end histone mRNA exonuclease activity and degradation of RNA substrates (PubMed:14536070, PubMed:16912046, PubMed:17135487). Also able to degrade the 3'-overhangs of short interfering RNAs (siRNAs) in vitro, suggesting a possible role as regulator of RNA interference (RNAi) (PubMed:14961122). Required for binding the 5'-ACCCA-3' sequence present in stem-loop structure (PubMed:14536070, PubMed:16912046). Able to bind other mRNAs (PubMed:14536070, PubMed:16912046). Required for 5.8S rRNA 3'-end processing (PubMed:37352860). Also binds to 5.8s ribosomal RNA (By similarity). Binds with high affinity to the stem- loop structure of replication-dependent histone pre-mRNAs (PubMed:14536070, PubMed:16912046, PubMed:17135487). In vitro, does not have sequence specificity (PubMed:17135487). In vitro, has weak DNA exonuclease activity (PubMed:17135487). In vitro, shows biphasic kinetics such that there is rapid hydrolysis of the last three unpaired RNA nucleotides in the 39 flanking sequence followed by a much slower cleavage through the stem that occurs over a longer incubation period in the order of hours (PubMed:17135487). ERI1-mediated RNA metabolism plays a key role in chondrogenesis (PubMed:37352860). {ECO:0000250|UniProtKB:Q7TMF2, ECO:0000269|PubMed:14536070, ECO:0000269|PubMed:14961122, ECO:0000269|PubMed:16912046, ECO:0000269|PubMed:17135487, ECO:0000269|PubMed:37352860}. This is the function of ERI1 (exoribonuclease 1, Ensembl gene identifier ENSG00000104626).