5CEG image
Deposition Date 2015-07-06
Release Date 2015-11-11
Last Version Date 2024-03-06
Entry Detail
PDB ID:
5CEG
Keywords:
Title:
X-ray structure of toxin/anti-toxin complex from Mesorhizobium opportunistum
Biological Source:
Method Details:
Experimental Method:
Resolution:
1.59 Å
R-Value Free:
0.19
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
I 2 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Addiction module antidote protein, CopG/Arc/MetJ family
Gene (Uniprot):Mesop_5599
Chain IDs:A, C
Chain Length:93
Number of Molecules:2
Biological Source:Mesorhizobium opportunistum (strain LMG 24607 / HAMBI 3007 / WSM2075)
Polymer Type:polypeptide(L)
Molecule:Plasmid stabilization system
Gene (Uniprot):Mesop_5598
Chain IDs:B, D
Chain Length:117
Number of Molecules:2
Biological Source:Mesorhizobium opportunistum (strain LMG 24607 / HAMBI 3007 / WSM2075)
Primary Citation
Evolving New Protein-Protein Interaction Specificity through Promiscuous Intermediates.
Cell 163 594 606 (2015)
PMID: 26478181 DOI: 10.1016/j.cell.2015.09.055

Abstact

Interacting proteins typically coevolve, and the identification of coevolving amino acids can pinpoint residues required for interaction specificity. This approach often assumes that an interface-disrupting mutation in one protein drives selection of a compensatory mutation in its partner during evolution. However, this model requires a non-functional intermediate state prior to the compensatory change. Alternatively, a mutation in one protein could first broaden its specificity, allowing changes in its partner, followed by a specificity-restricting mutation. Using bacterial toxin-antitoxin systems, we demonstrate the plausibility of this second, promiscuity-based model. By screening large libraries of interface mutants, we show that toxins and antitoxins with high specificity are frequently connected in sequence space to more promiscuous variants that can serve as intermediates during a reprogramming of interaction specificity. We propose that the abundance of promiscuous variants promotes the expansion and diversification of toxin-antitoxin systems and other paralogous protein families during evolution.

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Primary Citation of related structures