5KTG

Crystal structure of mouse Bak BH3-in-groove homodimer (GFP)

Summary for 5KTG

• Entry DOI: 10.2210/pdb5ktg/pdb
• Descriptor: Green fluorescent protein, Bcl-2 homologous antagonist/killer (1 entity in total)
• Functional Keywords: bcl-2 family proteins, mitochondrial outer membrane permeabilization, apoptosis regulators, pore-forming proteins, apoptosis
• Biological source: Aequorea victoria (Jellyfish); More
• Total number of polymer chains: 2
• Total formula weight: 69804.74

Authors

Mandal, T.,Choe, J.-Y.,Oh, K.J. (deposition date: 2016-07-11, release date: 2016-08-17, Last modification date: 2024-10-09)

Primary citation

Mandal, T.,Shin, S.,Aluvila, S.,Chen, H.C.,Grieve, C.,Choe, J.Y.,Cheng, E.H.,Hustedt, E.J.,Oh, K.J.
Assembly of Bak homodimers into higher order homooligomers in the mitochondrial apoptotic pore.
Sci Rep, 6:30763-30763, 2016

PubMed Abstract: In mitochondrial apoptosis, Bak is activated by death signals to form pores of unknown structure on the mitochondrial outer membrane via homooligomerization. Cytochrome c and other apoptotic factors are released from the intermembrane space through these pores, initiating downstream apoptosis events. Using chemical crosslinking and double electron electron resonance (DEER)-derived distance measurements between specific structural elements in Bak, here we clarify how the Bak pore is assembled. We propose that previously described BH3-in-groove homodimers (BGH) are juxtaposed via the 'α3/α5' interface, in which the C-termini of helices α3 and α5 are in close proximity between two neighboring Bak homodimers. This interface is observed concomitantly with the well-known 'α6:α6' interface. We also mapped the contacts between Bak homodimers and the lipid bilayer based on EPR spectroscopy topology studies. Our results suggest a model for the lipidic Bak pore, whereby the mitochondrial targeting C-terminal helix does not change topology to accommodate the lining of the pore lumen by BGH.

PubMed: 27488021
DOI: 10.1038/srep30763

Experimental method

X-RAY DIFFRACTION (2.802 Å)