Small Disulphide-rich Folds
Here we see examples of the main families of small disulphide-rich domains of known structure. There are also `Small' domains without disulphides, which could have been grouped here, but instead are grouped under all-alpha or all-beta as appropriate (eg glucagon).
The Structural Classification of Proteins database (Alexey G. Murzin, Steven E. Brenner, Tim J.P. Hubbard, and Cyrus Chothia) currently lists thirty-eight categories of 'small' folds.
Also examine Jane Richardson's 'Protein Tourist 4' Kinemage, A Survey of Proteins in the 'Small Irregular' Category of Tertiary Structure.
Please note that the colour in the images below is purely artefactual, and merely serves to help in visualisation, but has no other significance. This form of representation does not actually show where the disulphide bonds are. To see this important feature, display the coordinate files served here with RasMol, and select from the menu Display: Wireframe, Sticks, Spacefill, or Ball & Stick, and Colour:CPK to see the yellow of the sulphur in the (usually buried) cysteines. Alternatively type the commands into the RasMol window: select sulphur; colour yellow; ssbonds 100 for example.
Last updated 7th April '97