How to Change the Oligomeric State of a Circular Protein Assembly: Switch from 11-Subunit to 12-Subunit TRAP Suggests a General Mechanism Molecular Switch between Protein Oligomers
2011

Changing the Oligomeric State of a Circular Protein Assembly

publication Evidence: high

Author Information

Author(s): Chen Chao-Sheng, Smits Callum, Dodson Guy G., Shevtsov Mikhail B., Merlino Natalie, Gollnick Paul, Antson Alfred A.

Primary Institution: York Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom

Hypothesis

How can the subunit number of a circular protein assembly be manipulated?

Conclusion

The subunit number of the TRAP oligomer can be manipulated by introducing deletion or addition mutations at the subunit interface.

Supporting Evidence

  • Bacillus subtilis and Bacillus stearothermophilus TRAP form 11-subunit oligomers.
  • Bacillus halodurans TRAP exclusively forms 12-subunit assemblies.
  • The two states of TRAP are related by a simple rigid body rotation of individual subunits around inter-subunit axes.
  • Removal of five C-terminal residues or extension of an amino acid side chain can increase the subunit number from 11 to 12.
  • The findings suggest that similar principles may apply to other circular assemblies.

Takeaway

Scientists found a way to change how many pieces make up a circular protein by adding or removing tiny parts of it.

Methodology

The study involved using crystal structures and mass spectrometry to analyze the TRAP protein from different Bacillus species.

Digital Object Identifier (DOI)

10.1371/journal.pone.0025296

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