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From Proteopedia
Structure of the CED-4 Apoptosome
Structural highlights
FunctionCED4_CAEEL Isoform a plays a major role in programmed cell death (PCD, apoptosis). Egl-1 binds to and directly inhibits the activity of ced-9, releasing the cell death activator ced-4 from a ced-9/ced-4 containing protein complex and allowing ced-4 to activate the cell-killing caspase ced-3. Isoform b prevents PCD.[1] [2] [3] [4] [5] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe CED-4 homo-oligomer or apoptosome is required for initiation of programmed cell death in Caenorhabditis elegans by facilitating autocatalytic activation of the CED-3 caspase zymogen. How the CED-4 apoptosome assembles and activates CED-3 remains enigmatic. Here we report the crystal structure of the complete CED-4 apoptosome and show that it consists of eight CED-4 molecules, organized as a tetramer of an asymmetric dimer via a previously unreported interface among AAA(+) ATPases. These eight CED-4 molecules form a funnel-shaped structure. The mature CED-3 protease is monomeric in solution and forms an active holoenzyme with the CED-4 apoptosome, within which the protease activity of CED-3 is markedly stimulated. Unexpectedly, the octameric CED-4 apoptosome appears to bind only two, not eight, molecules of mature CED-3. The structure of the CED-4 apoptosome reveals shared principles for the NB-ARC family of AAA(+) ATPases and suggests a mechanism for the activation of CED-3. Crystal structure of the Caenorhabditis elegans apoptosome reveals an octameric assembly of CED-4.,Qi S, Pang Y, Hu Q, Liu Q, Li H, Zhou Y, He T, Liang Q, Liu Y, Yuan X, Luo G, Li H, Wang J, Yan N, Shi Y Cell. 2010 Apr 30;141(3):446-57. PMID:20434985[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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