Endoribonuclease that cleaves tRNAs and rRNAs (PubMed:29563550). Cleaves tRNAs 11 nucleotides from the 3'-terminus at the acceptor stem (PubMed:29563550). Does not act on tRNA(Sec) (PubMed:29563550). Able to restrict HIV-1 virus replication; ability to inhibit HIV-1 replication is dependent on endoribonuclease activity (PubMed:29563550). . This is the function of ENSG00000154760 (SLFN13, schlafen family member 13).