A method for modifying structural gene sequences to enhance the expression
of the protein product is disclosed. Also disclosed are novel structural
genes which encode insecticidal proteins of B.t.k. HD-1, B.t.k. HD-73,
B.t. tenebrionis, B.t. entomocidus, 2 protein of B.t.k. HD-1, and the
coat protein of potato leaf roll virus.