Im9: Difference between revisions

{{STRUCTURE_1imq |  PDB=1imq |  SCENE= }}

 

Im9 is the immunity protein made by ''E. coli'' at the same time as [[Colicin E9]] to protect itself from the DNase activity of the colicin. Im9 binds with high affinity to colicin E9, and is only released upon entry of colicin E9 to a target ''E. coli'' cell. The structure shown is that of the Colicin E9 DNase domain bound to Im9<ref> PMID: 19890319 </ref>. When Im9 binds to colicin E9, 6 lysine residues become less accessible<ref> PMID: 16713291 </ref>, and it is hypothesised that that the binding physically blocks one of the major dsDNA binding sites<ref> PMID: 14962381 </ref>. It is also hypothesised that the conformational dynamics of amino acids in the DNA binding domain change when Im9 binds, again preventing dsDNA binding<ref> PMID: 16713291 </ref>.