HIGH SEQUENCE SIMILARITY BETWEEN A RIBONUCLEASE FROM GINSENG CALLUSESAND FUNGUS-ELICITED PROTEINS FROM PARSLEY INDICATES THAT INTRACELLULAR PATHOGENESIS-RELATED PROTEINS ARE RIBONUCLEASES

A ribonuclease from a callus cell culture of Panax ginseng C.A. Mey st rain R1 was isolated. A pure protein with an apparent molecular mass o f 18 kDa was obtained. The N-terminal sequences of the protein and of the C-terminal CNBr peptide were determined. No homology with other ri bonucleases was found, but there was 60-70% sequence identity with two intracellular pathogenesis-related (IPR) proteins from parsley, indic ating that not only these two proteins, but also homologous IPR protei ns identified in other plant species are ribonucleases.