“…An important question is whether the conformation of this species in solution is similar to or different from that of the monomeric unit in the hexameric form as determined by X-ray crystallography. There is very little direct evidence in the literature on this point, but the data that do exist (Wood et al, 1975;Chothia et at., 1983;Kaplan et al, 1984) indicate that the structures are probably very similar. The evidence, however, is far from conclusive on this point, since evidence for substantial differences has been reported (Pocker & Biswas, 1980).…”