This web page uses the open-source Java Applet program Jmol, a proposed platform-independent replacement for Chime and Rasmol, neither of which is available in an OS X native version. You will need a relatively recent Java Virtual Machine to use it. Currently using Jmol 13.0.18.

 

This is an idealized antiparallel beta sheet, via InsightII. Buttons parallel those for the alpha helix. Right-click or control-click to bring up the menu and use the built-in rendering commands to explore Note that all the hydrogen bond valences on the inner face of each strand are satisfied, but there are available donors and acceptors at the edges. Side chains alternate above and below the sheet, and they have more room than side chains on a helix.

Go to the alpha helix.

Click here for the same alpha helix in a real protein (the GCN4-DNA complex).

Click here for the same beta sheet in the protein tendamistat.
Teaching resources. J. Kahn home page.