Protein folds in the all alpha-helix class
I. Three to Six Helices
The B domain of
S. aureus
protein A.
Packing a pair of
a
helices at an angle relative to one another permits their contacting side chains to interdigitate efficiently.
Toggle transparent view (for all models).
Tryptophan repressor.
An excellent example of how motifs, in this case the common
helix-loop-helix motif,
are combined to create a fold.
Endonuclease III.
alpha-
helices tend to pack around a central helix when the assembly contains five or more helices. Note that one helix is broken. The break occurs at a single Gly (green trace) in the middle of the helix.
HIV-1 matrix protein (p17).
The presence of a Pro residue (green) near the C-terminal end of one helix causes a bend in the helix.
Spacefill HIV p17.