Engineering the hCRBPII Domain-Swapped Dimer into a New Class of Protein Switches.
J Am Chem Soc
; 141(43): 17125-17132, 2019 10 30.
Article
in En
| MEDLINE
| ID: mdl-31557439
ABSTRACT
Protein conformational switches or allosteric proteins play a key role in the regulation of many essential biological pathways. Nonetheless, the implementation of protein conformational switches in protein design applications has proven challenging, with only a few known examples that are not derivatives of naturally occurring allosteric systems. We have discovered that the domain-swapped (DS) dimer of hCRBPII undergoes a large and robust conformational change upon retinal binding, making it a potentially powerful template for the design of protein conformational switches. Atomic resolution structures of the apo- and holo-forms illuminate a simple, mechanical movement involving sterically driven torsion angle flipping of two residues that drive the motion. We further demonstrate that the conformational "readout" can be altered by addition of cross-domain disulfide bonds, also visualized at atomic resolution. Finally, as a proof of principle, we have created an allosteric metal binding site in the DS dimer, where ligand binding results in a reversible 5-fold loss of metal binding affinity. The high resolution structure of the metal-bound variant illustrates a well-formed metal binding site at the interface of the two domains of the DS dimer and confirms the design strategy for allosteric regulation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Engineering
/
Retinol-Binding Proteins, Cellular
Language:
En
Journal:
J Am Chem Soc
Year:
2019
Document type:
Article
Affiliation country:
United States