Improved methods for building protein models in electron density maps and the location of errors in these models. Acta Crystallogr. sect-英文文献.pdf

110 Acta Cryst. (1991). A47, 110-119 Improved Methods for Building Protein Models in Electron Density Maps and the Location of Errors in these Models BY T. A. JONES,* J.-Y. ZOU AND S. W. COWAN Department of Molecular Biology, BMC, Box 590, S-75124 Uppsala, Sweden AND M. KJELDGAARD Department of Chemistry, Universityof Aarhus, DK-8000, Aarhus, Denmark (Received 1 June 1990; accepted 7 September 1990) Abstract Levitt, 1978), fast Fourier transform methods to speed up the calculations (Agarwal, 1978) and, Map interpretation remains a critical step in solving more recently, force-field-based molecular-dynamics the structure of a macromolecule. Errors introduced algorithms (Briinger, Kuriyan Karplus, 1987; at this early stage may persist throughout crystallo- Fujinaga, Gros Van Gunsteren, 1989). Fortunately, graphic refinement and result in an incorrect struc- the decrease in the price/performance of computers ture. The normally quoted crystallographic residual has allowed us more or less to keep up with the is often a