Tropomyosin

This is an 81 residue fragment of the much longer muscle protein tropomyosin. Alanine residues are colored red. Leucine residues are colored blue. Notice two distinct kinds of regions at the helix interface.

Deciphering the design of the tropomyosin molecule. Brown, J.H., Kim, K.-H., Jun, G., Greenfield, N.J., Dominguez, R., Volkmann, N., Hitchcock-DeGregori, S.E., Cohen, C., (2001) Proc.Natl.Acad.Sci.USA 98: 8496-8501
(PubMed)

1ic2 (PDB)