Learning an Objective Alphabet of Amino Acid Conformations in Protein11By acceptance of this article, the publisher and/or recipient acknowledges the U.S. Government's right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper. This research was supported by the Northwest College and University Association for Science (Washington State University) under grant DE-FG06-89ER-75522 with the U.S. Department of Energy.