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Building a pseudo-atomic model of the anaphase-promoting complex
Kiran Kulkarni1, Ziguo Zhang, Leifu Chang
1Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, England.
Acta Crystallographica. Section D, Biological Crystallography
|November 6, 2013
Summary
The anaphase-promoting complex (APC/C), a large E3 ubiquitin ligase, regulates cell cycle progression. Researchers created a pseudo-atomic model of the APC/C complex using cryo-EM and crystallography.
Area of Science:
- Cell Biology
- Structural Biology
- Biochemistry
Background:
- The anaphase-promoting complex (APC/C) is a crucial E3 ubiquitin ligase.
- It regulates cell cycle progression by degrading key regulatory proteins.
- The active APC/C is a large, multi-subunit complex (approx. 1.3 MDa).
Purpose of the Study:
- To generate pseudo-atomic models of the anaphase-promoting complex (APC/C).
- To visualize various functional states of the APC/C.
- To map APC/C subunits within the complex structure.
Main Methods:
- Single-particle electron microscopy (cryo-EM) was used to determine the overall structure.
- Protein crystallography provided high-resolution structures of individual APC/C subunits.
- Computational methods were employed to assign subunit locations within the EM density map.
Main Results:
- A hybrid approach combined cryo-EM and crystallography data.
- Three distinct methods were developed for mapping subunits to the EM map.
- A pseudo-atomic model was generated for 80% of the APC/C complex.
Conclusions:
- The study successfully generated a pseudo-atomic model of the APC/C.
- This structural information aids in understanding APC/C function and regulation.
- The developed methods are valuable for studying large protein complexes.
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