CDNA CLONING FOR A PUTATIVE CYSTEINE PROTEINASE FROM DEVELOPING SEEDSOF SOYBEAN

cDNA clones for a putative cysteine proteinase were isolated from deve loping cotyledons of soybean (Glycine max.) using PCR-based techniques . The full-length clone of 1441 bp encodes a proteinase pre-propolypep tide of 380 amino acids. It belongs to the commonly known papain famil y and shows the highest sequence homology (up to 53% identity) to the protein 15A, a turgor-responsive cysteine proteinase of pea, as well a s to several other stress inducible proteinases. Biosynthesis of the c orresponding transcripts was shown to be developmentally controlled du ring embryogenesis. Southern analyses revealed occurrence of one to tw o genes in the soybean genome.