Inactivation of colicin Y by intramembrane helix helix interaction with its immunity protein
| Title in English | Inactivation of colicin Y by intramembrane helixhelix interaction with its immunity protein |
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| Authors | |
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | FEBS Journal |
| MU Faculty or unit | |
| Citation | |
| Field | Genetics and molecular biology |
| Keywords | colicin immunity; colicin Y; helix helix interaction; pore orming colicin; site drected mutagenesis |
| Description | Construction of hybrids between colicins U and Y and mutagenesis of colicin Y gene (cya) revealed amino acid residues important for interactions between colicin Y and its cognate immunity protein (Cyi). Four such residues (I578, T582, Y586, and V590) were found in helices 8 and 9 of the colicin Y pore forming domain. To verify the importance of these residues, the corresponding amino acids in the colicin B protein were mutated to the residues present in colicin Y. An E. coli strain with cloned colicin Y immunity gene (cyi) inactivated this mutant but not the wildtype colicin B. In addition, interacting amino acid pairs in Cya and Cyi were identified using a set of Cyi point mutant strains. These data are consistent with antiparallel helix-helix interactions between Cyi helix T3 and Cya helix 8 of the pore-forming domain as a molecular mechanism of colicin Y inactivation by its immunity protein. |
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