Download MendeleyFormation and carbon monoxide-dependent dissociation of Allochromatium vinosum cytochrome c' oligomers using domain-swapped dimers
Yamanaka, M., Hoshizumi, M., Nagao, S., Nakayama, R., Shibata, N., Higuchi, Y., Hirota, S.(2017) Protein Sci 26: 464-474
- PubMed: 27883268
- DOI: https://doi.org/10.1002/pro.3090
- Primary Citation of Related Structures:
5GYR - PubMed Abstract:
The number of artificial protein supramolecules has been increasing; however, control of protein oligomer formation remains challenging. Cytochrome c' from Allochromatium vinosum (AVCP) is a homodimeric protein in its native form, where its protomer exhibits a four-helix bundle structure containing a covalently bound five-coordinate heme as a gas binding site. AVCP exhibits a unique reversible dimer-monomer transition according to the absence and presence of CO. Herein, domain-swapped dimeric AVCP was constructed and utilized to form a tetramer and high-order oligomers. The X-ray crystal structure of oxidized tetrameric AVCP consisted of two monomer subunits and one domain-swapped dimer subunit, which exchanged the region containing helices αA and αB between protomers. The active site structures of the domain-swapped dimer subunit and monomer subunits in the tetramer were similar to those of the monomer subunits in the native dimer. The subunit-subunit interactions at the interfaces of the domain-swapped dimer and monomer subunits in the tetramer were also similar to the subunit-subunit interaction in the native dimer. Reduced tetrameric AVCP dissociated to a domain-swapped dimer and two monomers upon CO binding. Without monomers, the domain-swapped dimers formed tetramers, hexamers, and higher-order oligomers in the absence of CO, whereas the oligomers dissociated to domain-swapped dimers in the presence of CO, demonstrating that the domain-swapped dimer maintains the CO-induced subunit dissociation behavior of native ACVP. These results suggest that protein oligomer formation may be controlled by utilizing domain swapping for a dimer-monomer transition protein.
Organizational Affiliation:
Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
