BASE NONSPECIFIC ACID RIBONUCLEASE FROM IRPEX LACTEUS, PRIMARY STRUCTURE AND PHYLOGENETIC-RELATIONSHIPS IN RNASE T-2 FAMILY ENZYME

Two base non-specific acid RNases (RNase Irp(1) and RNase Irp(2)) were purified from a commercial enzyme, ''Driselase'' (Irpex lacteus) in a homogeneous state on SDS-PAGE by several steps of chromatographic sep arations. RNAse Irp(2) was a simple polypeptide with 235 amino acid re sidues and RNase Irp(1) was a glycopeptide with 248 amino acid residue s. The amino acid sequences of both RNases were identified by Edman de gradation of the peptides derived from these RNAses, RNase Irp(1) was composed of the RNase Irp(2) and extra C-terminal 13 residues of pepti de, The phylogenetic relation of these RNases with the other fungal RN ases already known was discussed, The sequence of RNase Irp(2) was ver y highly homologous (67.5%) with that of RNase Le(2) from Lentinus edo des.