3TCJ

CcdB dimer from V. fisheri in complex with one C-terminal domain of F-plasmid CcdA

Summary for 3TCJ

• Entry DOI: 10.2210/pdb3tcj/pdb
• Related: 3G7F 3HPW 3JRZ 3JSC 3KU8 3KUA
• Descriptor: CcdB, Protein CcdA, ACETATE ION, ... (4 entities in total)
• Functional Keywords: alpha+beta sh3 domain intrinsically disordered, toxin-antitoxin complex, toxin/antitoxin
• Biological source: Aliivibrio fischeri; More
• Total number of polymer chains: 3
• Total formula weight: 28195.32

Authors

De Jonge, N.,Loris, R. (deposition date: 2011-08-09, release date: 2012-08-15, Last modification date: 2023-09-13)

Primary citation

Drobnak, I.,De Jonge, N.,Haesaerts, S.,Vesnaver, G.,Loris, R.,Lah, J.
Energetic basis of uncoupling folding from binding for an intrinsically disordered protein.
J.Am.Chem.Soc., 135:1288-1294, 2013

PubMed Abstract: Intrinsically disordered proteins (IDPs) are proteins that lack a unique three-dimensional structure in their native state. Many have, however, been found to fold into a defined structure when interacting with specific binding partners. The energetic implications of such behavior have been widely discussed, yet experimental thermodynamic data is scarce. We present here a thorough thermodynamic and structural study of the binding of an IDP (antitoxin CcdA) to its molecular target (gyrase poison CcdB). We show that the binding-coupled folding of CcdA is driven by a combination of specific intramolecular interactions that favor the final folded structure and a less specific set of intermolecular contacts that provide a desolvation entropy boost. The folded structure of the bound IDP appears to be defined largely by its own amino acid sequence, with the binding partner functioning more as a facilitator than a mold to conform to. On the other hand, specific intermolecular interactions do increase the binding affinity up to the picomolar range. Overall, this study shows how an IDP can achieve very strong and structurally well-defined binding and it provides significant insight into the molecular forces that enable such binding properties.

PubMed: 23289531
DOI: 10.1021/ja305081b

Experimental method

X-RAY DIFFRACTION (1.93 Å)