Structural highlights
Function
[IMM7_ECOLX] This protein is able to protect a cell, which harbors the plasmid ColE7 encoding colicin E7, against colicin E7, it binds specifically to the DNase-type colicin and inhibits its bactericidal activity. Dimeric ImmE7 may possess a RNase activity that cleaves its own mRNA at a specific site and thus autoregulates translational expression of the downstream ceiE7 gene as well as degradation of the upstream ceaE7 mRNA. [CEA7_ECOLX] This plasmid-coded bactericidal protein is an endonuclease active on both single- and double-stranded DNA but with undefined specificity. Colicins are polypeptide toxins produced by and active against E.coli and closely related bacteria.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The redesign of protein-protein interactions is a stringent test of our understanding of molecular recognition and specificity. Previously we engineered a modest specificity switch into the colicin E7 DNase-Im7 immunity protein complex by identifying mutations that are disruptive in the native complex, but can be compensated by mutations on the interacting partner. Here we extend the approach by systematically sampling alternate rigid body orientations to optimize the interactions in a binding mode specific manner. Using this protocol we designed a de novo hydrogen bond network at the DNase-immunity protein interface and confirmed the design with X-ray crystallographic analysis. Subsequent design of the second shell of interactions guided by insights from the crystal structure on tightly bound water molecules, conformational strain, and packing defects yielded new binding partners that exhibited specificities of at least 300-fold between the cognate and the non-cognate complexes. This multi-step approach should be applicable to the design of polar protein-protein interactions and contribute to the re-engineering of regulatory networks mediated by protein-protein interactions.
Computational design of a new hydrogen bond network and at least a 300-fold specificity switch at a protein-protein interface.,Joachimiak LA, Kortemme T, Stoddard BL, Baker D J Mol Biol. 2006 Aug 4;361(1):195-208. Epub 2006 May 24. PMID:16831445[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Joachimiak LA, Kortemme T, Stoddard BL, Baker D. Computational design of a new hydrogen bond network and at least a 300-fold specificity switch at a protein-protein interface. J Mol Biol. 2006 Aug 4;361(1):195-208. Epub 2006 May 24. PMID:16831445 doi:10.1016/j.jmb.2006.05.022
