logo.gif (3296 bytes)Introduction to Protein Structure

Tertiary Structure

Tertiary structure refers to the overall three-dimensional structure of a single polypeptide chain. Regions of regular secondary structure (e.g. alpha helicies and beta sheets) "fold up" along with the "randomly" coiled regions into a compact, generally globular structure.

Tertiary structure is stabilized by  noncovalent interactions and, in some cases, by covalent disulfide bonds.

Shown below is the tertiary structure of lysozyme. The default is a cartoon view with the alpha helices and the beta sheets color coded.






 On  Off

         H bonds

         Disulfide bonds



Structure Key:

alpha helix 

beta sheet  

"random" coil

Color by:    


Copyright 1998, 1999, 2007 by Frank R. Gorga;   Page maintained by F.R. Gorga;   Last updated: 12-Mar-2007