You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Effect of Errors, Redundancy, and Solvent Content in the Molecular Replacement Procedure for the Structure Determination of Biological Macromolecules
Edward Arnold and Michael G. Rossmann
Proceedings of the National Academy of Sciences of the United States of America
Vol. 83, No. 15 (Aug. 1, 1986), pp. 5489-5493
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/27664
Page Count: 5
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
The power of molecular replacement as a tool for analyzing macromolecular structures such as viruses has been demonstrated by an increasing number of successful determinations. We examine here the effects of (i) noncrystallographic redundancy, N; (ii) the fraction of solvent volume (1 -- U/V); (iii) error in structure amplitude measurements, R; (iv) the fraction, f, of the unique data that were measured; (v) error in the description of the noncrystallographic symmetry; and (vi) definition of the molecular envelope. The formula P = (Nf)1/2/R(U/V) has been derived and represents the inherent phasing power (P) for a given problem. The ability of ``solvent flattening'' procedures to determine phases was analyzed and found to be analogous to the effect of noncrystallographic redundancy. However, in the limiting case, the effect of solvent flattening approaches the power of Sayre's equations.
Proceedings of the National Academy of Sciences of the United States of America © 1986 National Academy of Sciences