Premium
Investigation of the specificity of the interaction between colicin E9 and its immunity protein by site‐directed mutagenesis
Author(s) -
Curtis M. D.,
James R.
Publication year - 1991
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1991.tb01981.x
Subject(s) - colicin , biology , mutagenesis , mutant , escherichia coli , genetics , amino acid , site directed mutagenesis , phenotype , gene
Summary Comparison of the amino acid sequences of the C‐terminal domain of three DNAase type E colicins has identified six candidate specificity determinants for the interaction of these E colicins with their homologous immunity proteins. We have changed these candidate specificity determinants of colicin E9, using site‐directed mutagenesis, to the corresponding amino‐acids of colicin E8. A‘mutant’colicin E9, in which four of the six candidate specificity determininants have been changed, demonstrated colicin activity against Escherichia coli indicator strains which carried either the E8imm or the E9imm genes, indicative of a‘novel’E colicin. After changing all six of the candidate specificity determinants, the resulting colicin E9‘mutant’exhibited a phenotype very similar to that of colicin E8.