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Publication Abstract from PubMed

The Drosophila Apaf-1 related killer forms an apoptosome in the intrinsic cell death pathway. In this study we show that Dark forms a single ring when initiator procaspases are bound. This Dark-Dronc complex cleaves DrICE efficiently; hence, a single ring represents the Drosophila apoptosome. We then determined the 3D structure of a double ring at approximately 6.9 A resolution and created a model of the apoptosome. Subunit interactions in the Dark complex are similar to those in Apaf-1 and CED-4 apoptosomes, but there are significant differences. In particular, Dark has "lost" a loop in the nucleotide-binding pocket, which opens a path for possible dATP exchange in the apoptosome. In addition, caspase recruitment domains (CARDs) form a crown on the central hub of the Dark apoptosome. This CARD geometry suggests that conformational changes will be required to form active Dark-Dronc complexes. When taken together, these data provide insights into apoptosome structure, function, and evolution.

Structure of the Drosophila apoptosome at 6.9 a resolution.,Yuan S, Yu X, Topf M, Dorstyn L, Kumar S, Ludtke SJ, Akey CW Structure. 2011 Jan 12;19(1):128-40. PMID:21220123^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.