Bachmann, G, Richards, MW, Winter, A, Beuron, F, Morris, E and Bayliss, R (2016) A closed conformation of the Caenorhabditis elegans separase-securin complex. Open Biology, 6 (4). 160032 - ?. ISSN 2046-2441

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The protease separase plays a key role in sister chromatid disjunction and centriole disengagement. To maintain genomic stability, separase activity is strictly regulated by binding of an inhibitory protein, securin. Despite its central role in cell division, the separase and securin complex is poorly understood at the structural level. This is partly owing to the difficulty of generating a sufficient quantity of homogeneous, stable protein. Here, we report the production of Caenorhabditis elegans separase-securin complex, and its characterization using biochemical methods and by negative staining electron microscopy. Single particle analysis generated a density map at a resolution of 21-24 Å that reveals a close, globular structure of complex connectivity harbouring two lobes. One lobe matches closely a homology model of the N-terminal HEAT repeat domain of separase, whereas the second lobe readily accommodates homology models of the separase C-terminal death and caspase-like domains. The globular structure of the C. elegans separase-securin complex contrasts with the more elongated structure previously described for the Homo sapiens complex, which could represent a different functional state of the complex, suggesting a mechanism for the regulation of separase activity through conformational change.

Item Type: Article
Additional Information: Published by the Royal Society under the terms of the Creative Commons Attribution License, which permits unrestricted use, provided the original author and source are credited.
Uncontrolled Keywords: Animals, Caenorhabditis elegans, Caenorhabditis elegans Proteins, Computational Biology, Intrinsically Disordered Proteins, Models, Molecular, Multiprotein Complexes, Protein Domains, Protein Stability, Securin, Separase, chromosome segregation, electron microscopy, mitosis, protein purification
Subjects: Q Science > QD Chemistry
Divisions: Faculty of Natural Sciences > School of Physical and Geographical Sciences
Related URLs:
Depositing User: Symplectic
Date Deposited: 02 Mar 2017 15:49
Last Modified: 22 Nov 2018 11:37

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