Figure 7 - full size

 

Figure 7.
Fro. 7. Schematic representation f (a) parallel and (b) antiparallel arrangements of the keto groups. he view is ede-on to the 0 plane. I

The above figure is reprinted by permission from Elsevier: J Mol Biol (1983, 166, 183-201) copyright 1983.