Crystal structure of BAK core domain BH3-groove-dimer in complex with phosphatidylglycerolCrystal structure of BAK core domain BH3-groove-dimer in complex with phosphatidylglycerol

Structural highlights

6uxp is a 8 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.492Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

BAK_HUMAN In the presence of an appropriate stimulus, accelerates programmed cell death by binding to, and antagonizing the anti-apoptotic action of BCL2 or its adenovirus homolog E1B 19k protein. Low micromolar levels of zinc ions inhibit the promotion of apoptosis.[1] [2]

Publication Abstract from PubMed

BAK and BAX are essential mediators of apoptosis that oligomerize in response to death cues, thereby causing permeabilization of the mitochondrial outer membrane. Their transition from quiescent monomers to pore-forming oligomers involves a well-characterized symmetric dimer intermediate. However, no essential secondary interface that can be disrupted by mutagenesis has been identified. Here we describe crystal structures of human BAK core domain (alpha2-alpha5) dimers that reveal preferred binding sites for membrane lipids and detergents. The phospholipid headgroup and one acyl chain (sn2) associate with one core dimer while the other acyl chain (sn1) associates with a neighboring core dimer, suggesting a mechanism by which lipids contribute to the oligomerization of BAK. Our data support a model in which, unlike for other pore-forming proteins whose monomers assemble into oligomers primarily through protein-protein interfaces, the membrane itself plays a role in BAK and BAX oligomerization.

BAK core dimers bind lipids and can be bridged by them.,Cowan AD, Smith NA, Sandow JJ, Kapp EA, Rustam YH, Murphy JM, Brouwer JM, Bernardini JP, Roy MJ, Wardak AZ, Tan IK, Webb AI, Gulbis JM, Smith BJ, Reid GE, Dewson G, Colman PM, Czabotar PE Nat Struct Mol Biol. 2020 Sep 14. pii: 10.1038/s41594-020-0494-5. doi:, 10.1038/s41594-020-0494-5. PMID:32929280[3]

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

See Also

References

  1. Chittenden T, Flemington C, Houghton AB, Ebb RG, Gallo GJ, Elangovan B, Chinnadurai G, Lutz RJ. A conserved domain in Bak, distinct from BH1 and BH2, mediates cell death and protein binding functions. EMBO J. 1995 Nov 15;14(22):5589-96. PMID:8521816
  2. Moldoveanu T, Liu Q, Tocilj A, Watson M, Shore G, Gehring K. The X-ray structure of a BAK homodimer reveals an inhibitory zinc binding site. Mol Cell. 2006 Dec 8;24(5):677-88. PMID:17157251 doi:10.1016/j.molcel.2006.10.014
  3. Cowan AD, Smith NA, Sandow JJ, Kapp EA, Rustam YH, Murphy JM, Brouwer JM, Bernardini JP, Roy MJ, Wardak AZ, Tan IK, Webb AI, Gulbis JM, Smith BJ, Reid GE, Dewson G, Colman PM, Czabotar PE. BAK core dimers bind lipids and can be bridged by them. Nat Struct Mol Biol. 2020 Sep 14. pii: 10.1038/s41594-020-0494-5. doi:, 10.1038/s41594-020-0494-5. PMID:32929280 doi:http://dx.doi.org/10.1038/s41594-020-0494-5

6uxp, resolution 2.49Å

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