Building a pseudo-atomic model of the anaphase-promoting complex
- Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB (United Kingdom)
This article describes an example of molecular replacement in which atomic models are used to interpret electron-density maps determined using single-particle electron-microscopy data. The anaphase-promoting complex (APC/C) is a large E3 ubiquitin ligase that regulates progression through specific stages of the cell cycle by coordinating the ubiquitin-dependent degradation of cell-cycle regulatory proteins. Depending on the species, the active form of the APC/C consists of 14–15 different proteins that assemble into a 20-subunit complex with a mass of approximately 1.3 MDa. A hybrid approach of single-particle electron microscopy and protein crystallography of individual APC/C subunits has been applied to generate pseudo-atomic models of various functional states of the complex. Three approaches for assigning regions of the EM-derived APC/C density map to specific APC/C subunits are described. This information was used to dock atomic models of APC/C subunits, determined either by protein crystallography or homology modelling, to specific regions of the APC/C EM map, allowing the generation of a pseudo-atomic model corresponding to 80% of the entire complex.
- OSTI ID:
- 22347836
- Journal Information:
- Acta Crystallographica. Section D: Biological Crystallography, Vol. 69, Issue Pt 11; Other Information: PMCID: PMC3817697; PMID: 24189235; PUBLISHER-ID: ba5200; OAI: oai:pubmedcentral.nih.gov:3817697; Copyright (c) Kulkarni et al. 2013; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0907-4449
- Country of Publication:
- Denmark
- Language:
- English
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