Download MendeleyFoldon unfolding mediates the interconversion between M(pro)-C monomer and 3D domain-swapped dimer.
Kang, X., Zhong, N., Zou, P., Zhang, S., Jin, C., Xia, B.(2012) Proc Natl Acad Sci U S A 109: 14900-14905
- PubMed: 22927388
- DOI: https://doi.org/10.1073/pnas.1205241109
- Primary Citation of Related Structures:
2LIZ - PubMed Abstract:
The C-terminal domain (M(pro)-C) of SARS-CoV main protease adopts two different fold topologies, a monomer and a 3D domain-swapped dimer. Here, we report that M(pro)-C can reversibly interconvert between these two topological states under physiological conditions. Although the swapped α(1)-helix is fully buried inside the protein hydrophobic core, the interconversion of M(pro)-C is carried out without the hydrophobic core being exposed to solvent. The 3D domain swapping of M(pro)-C is activated by an order-to-disorder transition of its C-terminal α(5)-helix foldon. Unfolding of this foldon promotes self-association of M(pro)-C monomers and functions to mediate the 3D domain swapping, without which M(pro)-C can no longer form the domain-swapped dimer. Taken together, we propose that there exists a special dimeric intermediate enabling the protein core to unpack and the α(1)-helices to swap in a hydrophobic environment, which minimizes the energy cost of the 3D domain-swapping process.
Organizational Affiliation:
Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing 100871, China.
