[Specificity of intracellular ribonucleases Pc1 and Pc2 of the fungus Penicillium claviforme].

The products of RNA and synthetic polynucleotides degradation by intracellular RNAses Pc1 and Pc2 of the fungus Penicillium claviforme were studied. It was shown that the enzymes possess the endonuclease activity and are not specific for the bases vicinal to the cleaved PDE bonds (EC 3.1.4.23). The increase of binding of the dinucleoside monophosphates by Pc1 and Pc2 dependent on the nucleoside at the 3'-end of the PDE bond is: A greater than C greater than G greater than U. This order is opposite for the rates of these substrates cleavage by the RNAses. A homologous specificity of the intracellular RNAse Pc1 and the extracellular RNAse II of Pen. claviforme has been revealed.