A ubiquitin-like peptide with ribonuclease activity against various polyhomoribonucleotides from the yellow mushroom Cantharellus cibarius.

A peptide, with a molecular weight of 9K and an N-terminal sequence identical to that of ubiquitin, was isolated from fresh fruiting bodies of the yellow mushroom Cantharellus cibarius. The peptide manifested ribonucleolytic activity toward poly A, poly C, poly G, and poly U, with the activity toward the first two polyhomoribonucleotides being higher. Maximal activity toward yeast tRNA was observed at a temperature of 70 degrees C and a pH of 7. The peptide was adsorbed on DEAE-cellulose, CM-Sepharose, and Q-Sepharose. The yield of the peptide was 7mg from 1.8kg mushroom.