International Tables for Crystallography

Patterson and molecular replacement techniques, and the use of noncrystallographic symmetry in phasing
L. Tong, M. G. Rossmann and E. Arnold. International Tables for Crystallography (2010). Vol. B, ch. 2.3, pp. 244-281  [ doi:10.1107/97809553602060000765 ]


Interpretation of Patterson maps lies at the foundation of most macromolecular structure elucidation processes, both in determining the position of heavy atoms and/or anomalous scatterers for the isomorphous replacement and anomalous-scattering methods, and in determining the orientation and position of a homologous protein model for the molecular replacement method. The dramatically increasing number of macromolecular structures is expected to broaden the applicability of the molecular replacement method, since suitable search models can be found for more and more unknown structures. The molecular replacement method also encompasses the use of noncrystallographic redundancy within a crystal or between crystal forms to phase and refine crystal structures. Applications of Patterson and molecular replacement techniques to structure determination including Patterson interpretation methods, rotation functions, translation functions, symmetry averaging, density modification and phase extension are discussed.

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About International Tables for Crystallography

International Tables for Crystallography is the definitive resource and reference work for crystallography. The series consists of nine volumes and comprises articles and tables of data relevant to crystallographic research and to applications of crystallographic methods in all sciences concerned with the structure and properties of materials.