1. Departments of Chemistry and of Molecular and Cell Biology and the California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720
2. This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev. 2006, 106 (8), 2095−3118, DOI: 10.1021/cr050301x; Published (Web) August 9, 2006. Updates to the text appear in red type.