3gjn | pdb_00003gjn

Following evolutionary paths to high affinity and selectivity protein-protein interactions using Colicin7 and Immunity proteins

spinqualitylabelsall models 3gjn, resolution 2.48Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3gjn is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.48Å Ligands: ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function IMM9_ECOLX This protein is able to protect a cell, which harbors the plasmid ColE9 encoding colicin E9, against colicin E9, it binds specifically to the DNase-type colicin and inhibits its bactericidal activity. 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 How do intricate multi-residue features such as protein-protein interfaces evolve? To address this question, we evolved a new colicin-immunity binding interaction. We started with Im9, which inhibits its cognate DNase ColE9 at 10(-14) M affinity, and evolved it toward ColE7, which it inhibits promiscuously (Kd > 10(-8) M). Iterative rounds of random mutagenesis and selection toward higher affinity for ColE7, and selectivity (against ColE9 inhibition), led to an approximately 10(5)-fold increase in affinity and a 10(8)-fold increase in selectivity. Analysis of intermediates along the evolved variants revealed that changes in the binding configuration of the Im protein uncovered a latent set of interactions, thus providing the key to the rapid divergence of new Im7 variants. Overall, protein-protein interfaces seem to share the evolvability features of enzymes, that is, the exploitation of promiscuous interactions and alternative binding configurations via 'generalist' intermediates, and the key role of compensatory stabilizing mutations in facilitating the divergence of new functions. Following evolutionary paths to protein-protein interactions with high affinity and selectivity.,Levin KB, Dym O, Albeck S, Magdassi S, Keeble AH, Kleanthous C, Tawfik DS Nat Struct Mol Biol. 2009 Oct;16(10):1049-55. Epub 2009 Sep 13. PMID:19749752 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Colicin 3D structures Colicin Immunity Protein Colicin immunity protein 3D structures

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