Is Single-Wavelength Anomalous Scattering Sufficient for Solving Phases? A Comparison of Different Methods for a 2.1 A Structure Solution

Acta Crystallogr D Biol Crystallogr. 1999 Sep;55(Pt 9):1620-2. doi: 10.1107/s0907444999007726.


The structure of rusticyanin is the largest unknown structure (M(r) = 16.8 kDa) which has been recently solved by the direct-methods approach using only single-wavelength anomalous scattering (SAS) data from the native protein [Harvey et al. (1998). Acta Cryst. D54, 629-635]. Here, the results of the Sim distribution approach [Hendrickson & Teeter (1981). Nature (London), 290, 107-113] and of the CCP4 procedure MLPHARE [Collaborative Computational Project, Number 4 (1994). Acta Cryst. D50, 760-763] are compared with those from direct methods. Analysis against the final refined model shows that direct methods produced significantly better phases (average phase error 56 degrees ) and therefore significantly better electron-density maps than the Sim distribution and MLPHARE approaches (average phase error was around 63 degrees in both cases).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azurin / analogs & derivatives*
  • Azurin / chemistry
  • Bacterial Proteins / chemistry
  • Crystallography, X-Ray / methods
  • Mathematical Computing
  • Protein Conformation
  • Scattering, Radiation
  • Solutions


  • Bacterial Proteins
  • Solutions
  • rusticyanin
  • Azurin