Zinc phosphodiesterase, which displays some tRNA 3'-processing endonuclease activity. Probably involved in tRNA maturation, by removing a 3'-trailer from precursor tRNA. Shows also activity toward a broad range of substrates, such as intron containing pre-tRNAs, 5' extended precursors and non-RNA substrates. Endonucleolytic cleavage of RNA, removing extra 3' nucleotides from tRNA precursor, generating 3' termini of tRNAs. A 3'-hydroxy group is left at the tRNA terminus and a 5'-phosphoryl group is left at the trailer molecule. Binds 2 Zn(2+) ions. Optimum pH is 7.0. Optimum temperature is 50 degrees Celsius. Homodimer. Belongs to the RNase Z family.