Although we got bits and pieces of supersecondary structure, nothing
we came up with looked like a complete model.

We felt that the conserved histidines, H174, H176, and H187 ought to
cluster, perhaps at a metal-binding site, but they did not cluster
naturally in any of our models.  When we forced clustering, we lost
predicted secondary structur.


This is try8-opt2, one of the few undertaker models in which the
histidines came close without being forced.  They don't really
cluster, but at least they are on the same side of the sheet.