This is a quick tutorial to indicate a trick that sometimes works for finding binding pockets and other deep cavities in protein surfaces. Start spock and type
fetch=1brl.pdb; makesurf
to load bacterial luciferase and surface it, or you can
accomplish the same tasks with the menus. Notice that this surface is
quite complicated, and finding something on it might be difficult. On the
``Alter 
Surfaces'' menu, toggle ``Reduce when building'' to
on, and select ``Resmooth surface''. Enter 5 times for the smoothing.
Spock will smooth and simplify the molecular surface, so that important
surface features are easier to spot. Depending on the initial complexity
of other surfaces, you may have to smooth them more or less times to get
the right level of detail.