CLONING OF A CRYV-TYPE INSECTICIDAL PROTEIN GENE FROM BACILLUS-THURINGIENSIS - THE CRYV-ENCODED PROTEIN IS EXPRESSED EARLY IN STATIONARY-PHASE

A CryV-type protein (CGCryV) has been isolated from supernatant fluids of Bacillus thuringiensis AB88 cultures. Previous reports have sugges ted the cryptic nature of the cryV-type genes on the basis of the abse nce of CryV-type proteins in parasporal crystals. The CryV-type protei n reported here is expressed early in stationary phase, and evidence i ndicates that it is an exported protein. Analysis of the deduced prote in sequence from this gene reveals the presence of an N-terminal domai n that likely acts as a signal peptide. The CGCryV protein is the firs t reported case of a delta-endotoxin being a secreted protein, which m ay influence the biological relevance of these proteins.