The KHR gene cloned from a genomic library was on 4.7-kbp DNA fragment and was inserted into YCpG11 vector (KHR-YCp) and YEp vector (KHP-YEp). Transformants with KHR-YEp could secrete 3-4 times as much killer toxin into the media as the donor strain. The complete nucleotide sequence of the KHR gene was analyzed. It was found that the KHR gene consisted of 888 bp. It was suggested that this protein was processed before being secreted into the media, because its molecular mass presumed from the nucleotide sequence was larger than that of the mature killer toxin.