Purification and characterization of the precursor tRNA 3'-end processing nuclease from Aspergillus nidulans.

The precursor-tRNA 3'-end processing nuclease activity was purified homogeneously about 15,300 fold from the heat-treated fraction. The precursor-tRNA 3'-end processing nuclease was a single polypeptide of 160,000 Da. This nuclease generates a mature 3'-end of nuclear tRNA(Asp) of Aspergillus nidulans by the endonuclease activity and prefers the 5'-end processed tRNA(Asp) rather than primary precursor-tRNA(Asp) as a substrate. However, this enzyme did not process both primary mitochondrial precursor-tRNA(His) and 5'-end processed mitochondrial precursor-tRNA(His) of A. nidulans.