comparison of the structural domains of the Cry1Aa, Cry11Bb, and
Cry3A. Upper view of domain I shows that the three toxins are almost
identical. Front view of domain II where most of the differences
among the three toxins are located, specifically in the loops at the
bottom of the figure, and probably due to the presence of specificity
determinants which recognize distinct receptors in the insect midgut
cells. Front view of domain III which does not show major differences
except for loop ß16-ß17, located at the bottom of the figure.