Abstract: The genes encoding a novel class of insecticidal proteins have been isolated and characterized from a strain of Bacillus thuringiensis. Both the nucleic and amino acid sequences for the proteins are disclosed. The nucleic acid molecules are utilized in the transformation of host microorganisms and production of transgenic plants which are resistant to insects. Also, the gene encoding for the insect's receptor of the insecticidal protein has been isolated and characterized. Novel processes and methods for controlling plants pests are provided.