title: Sub-Angstrom resolution enzyme X-ray structures: is seeing believing?
abstract: Recent technical advances in crystallographic analysis, particularly highly focused and high brilliance synchrotron beam lines, have significantly improved the resolutions that are attainable for many macromolecular crystal structures. The Protein Data Bank (http://www.rcsb.org/pdb/) contains an increasing number of atomic resolution structures, which are providing a wealth of structural information that was not previously visible in lower resolution electron density maps. Here, we review the importance of visualizing hydrogen atoms and multiple sidechain conformations or anisotropy, as well as substrate strain, at sub-Angstrom resolution. The additional structural features that are visible in the electron density maps as a result of atomic resolution data provide a better understanding of the catalytic mechanisms of cholesterol oxidase, ribonuclease A, beta-lactamase, serine proteases, triosephosphate isomerase and endoglucanase.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, University of California, 1156 High Street, Santa Cruz, CA 95064, USA. vrielink@biology.ucsc.edu
authors.forename: Alice
authors.initials: A
authors.lastname: Vrielink
authors.forename: Nicole
authors.initials: N
authors.lastname: Sampson
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray / Q000379:methods*; D004798:Enzymes / Q000032:analysis / Q000737:chemistry*; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: D004798:Enzymes