Different representations of an amphipathic beta sheet, from ubiquitin conjugating enzyme.
Animation sequence: 1) Space-filling model of the protein (blue) 2) Highlighting amphipathic (amphiphilic) beta sheet backbone (green ribbon) and side chains (pink = hydrophilic, yellow = hydrophobic) 3) Rest of protein backbone shown, also as green ribbon 4) Atoms of side chains shown: oxygen = red, nitrogen = blue, hydrogen = white. Carbons still shown as pink (hydrophilic side chains) or yellow (hydrophobic side chains) 5) Side chains in the rest of the protein core are shown (carbon = brown)
The protein folds due to the hydrophobic effect, so that nonpolar side chains are clustered inside the protein structure, away from the water, and the hydrophilic side chains interact with the water. As you follow along one beta strand, note that the side chains alternate between facing the solvent and facing the core.
From Protein Data Bank coordinates 2AAK, the ubiquitin conjugating enzyme from Arabidopsis thaliana
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