Jump to main content
Jump to site search

Issue 12, 2015
Previous Article Next Article

Domain-swapped cytochrome cb562 dimer and its nanocage encapsulating a Zn–SO4 cluster in the internal cavity

Author affiliations

Abstract

Protein nanostructures have been gaining in interest, along with developments in new methods for construction of novel nanostructures. We have previously shown that c-type cytochromes and myoglobin form oligomers by domain swapping. Herein, we show that a four-helix bundle protein cyt cb562, with the cyt b562 heme attached to the protein moiety by two Cys residues insertion, forms a domain-swapped dimer. Dimeric cyt cb562 did not dissociate to monomers at 4 °C, whereas dimeric cyt b562 dissociated under the same conditions, showing that heme attachment to the protein moiety stabilizes the domain-swapped structure. According to X-ray crystallographic analysis of dimeric cyt cb562, the two helices in the N-terminal region of one protomer interacted with the other two helices in the C-terminal region of the other protomer, where Lys51–Asp54 served as a hinge loop. The heme coordination structure of the dimer was similar to that of the monomer. In the crystal, three domain-swapped cyt cb562 dimers formed a unique cage structure with a Zn–SO4 cluster inside the cavity. The Zn–SO4 cluster consisted of fifteen Zn2+ and seven SO42− ions, whereas six additional Zn2+ ions were detected inside the cavity. The cage structure was stabilized by coordination of the amino acid side chains of the dimers to the Zn2+ ions and connection of two four-helix bundle units through the conformation-adjustable hinge loop. These results show that domain swapping can be applied in the construction of unique protein nanostructures.

Graphical abstract: Domain-swapped cytochrome cb562 dimer and its nanocage encapsulating a Zn–SO4 cluster in the internal cavity

Back to tab navigation

Supplementary files

Article information


Submitted
06 Jul 2015
Accepted
22 Sep 2015
First published
22 Sep 2015

This article is Open Access
All publication charges for this article have been paid for by the Royal Society of Chemistry

Chem. Sci., 2015,6, 7336-7342
Article type
Edge Article
Author version available

Domain-swapped cytochrome cb562 dimer and its nanocage encapsulating a Zn–SO4 cluster in the internal cavity

T. Miyamoto, M. Kuribayashi, S. Nagao, Y. Shomura, Y. Higuchi and S. Hirota, Chem. Sci., 2015, 6, 7336
DOI: 10.1039/C5SC02428E

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

Reproduced material should be attributed as follows:

  • For reproduction of material from NJC:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
  • For reproduction of material from PCCP:
    [Original citation] - Published by the PCCP Owner Societies.
  • For reproduction of material from PPS:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
  • For reproduction of material from all other RSC journals:
    [Original citation] - Published by The Royal Society of Chemistry.

Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.


Social activity

Search articles by author

Spotlight

Advertisements