 BAR Domain | |
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| Class:Phospholipid binding | |
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Structure:
The BAR domain of amphiphysin is approximately 210 amino acids in length and consists of a coiled coil composed of three extended alpha helices. Two monomers must dimerize however to form the functional banana shaped six helical bundle. Positive charges are clustered at the tips of the banana like structure and along its concave surface. These positive charges are thought to mediate binding to phospholipids where the curvature of the concave surface would fit a rounded membrane with a diameter of ~ 220 Angstroms.
Structure Reference: Peter, B.J. et al. (2004) Science 303(5657), 495-499."Amphiphysin Bar Domain From Drosophila" Tarricone, C. et al. (2001) Nature. 10;411(6834):215-9. PDB: 1I4D.
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Domain binding and function:
The BAR (Bin/Amphiphysin/Rvs) domain of Amphiphysin is approximately 210 amino acids in length and is found in over 35 proteins encoded in the human genome. These proteins function in diverse cellular processes such as endocytosis i.e. endophilins, sorting nexins, and amphiphysin and actin reorganization i.e. RhoGAPs and RhoGEFs. While all BAR domains probably bind curved lipids, a subset of BAR domains can actually induce membrane curvature. It is therefore predicted that BAR domains may function during vesiculation to either target proteins to curved membranes or to physically assist in inducing the curvature of the membrane. BAR domains can also bind proteins, for example, the BAR domain of Arfaptin has been shown to bind Rac1.
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Examples of Proteins:
Amphiphysin (AF034996)
Graf1 (NM_015071)
Arfaptin (AF124489)
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Referenced in part on Cell Signaling Technology Website, Reference Section on Protein Domains. We gratefully acknowledge the following contributors:
Piers Nash1, Dan Lin3, Kathleen Binns2, Clark Wells2, Rob Ingham2, Terry Kubiseski2, Bernard Liu1, Matt Smith2,3, Ivan Blasutig2,3, Maria Sierra1, Caesar Lim2,3, Michael Arc1, Jim Fawcett2 and Tony Pawson2,3.
1. Ben May Institute for Cancer Research, The University of Chicago, Chicago, Illinois, 60637, USA
2. Program in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada
3. Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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