Computation and mutagenesis suggest a right-handed structure for the synaptobrevin transmembrane dimer. |
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Authors: | K G Fleming D M Engelman |
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Affiliation: | Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA. karen.fleming@jhu.edu |
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Abstract: | Biological membrane fusion involves a highly precise and ordered set of protein-protein interactions. Synaptobrevin is a key player in this process. Mutagenesis studies of its single transmembrane segment suggest that it dimerizes in a sequence specific manner. Using the computational methods developed for the successful structure prediction of the glycophorin A transmembrane dimer, we have calculated a structural model for the synaptobrevin dimer. Our computational search yields a well-populated cluster of right-handed structures consistent with the experimentally determined dimerization motif. The three-dimensional structure contains an interface formed primarily by leucine and isoleucine side-chain atoms and has no interhelical hydrogen bonds. The model is the first three-dimensional picture of the synaptobrevin transmembrane dimer and provides a basis for further focused experimentation on its structure and association thermodynamics. |
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Keywords: | membrane protein structure model synaptobrevin SNARE |
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