As an aquaporin found in E. coli bacteria, GlpF would seem to be an uninformatively distant relation to the aquaporins found in humans. Not so, as it turns out. Any protein can be thought of as a sequence of amino acids that folds upon itself in a very precise way to build a functional structure. The amino acid sequences that determine the shapes of the various aquaporins have a high percentage of overlap from one to the other. Thus, solving the structure of one provides a tremendous leap toward understanding them all.
Radial lines indicate hydrophobic areas.
The arrows indicate the cross sections through the channel, shown at right. Operation of the ALS is supported by the U.S. Department of Energy, Office of Basic Energy Sciences.