| molecular structure and immunity specificity of colicin e6, an evolutionary intermediate between e-group colicins and cloacin df13. | the primary structure of a 3.1-kilobase e6 or e3 segment carrying colicin and related genes was determined. plasmid cole6-ct14 showed striking homology to cole3-ca38 throughout this segment, including homology to the secondary immunity gene, imme8, downstream of the e6 or e3 immunity gene. the cole3-ca38 and cole6-ct14 sequences, however, contained an exceptional hot spot region encoding both the colicin-active domain (rnase region) and the immunity protein, reflecting their different immunity s ... | 1989 | 2687234 |