AI Article Synopsis
- The study builds on previous work demonstrating that large sets of triplet phases can be measured using three-beam interference.
- It outlines a method for calculating an electron-density map using limited experimental phase data, specifically utilizing hen egg-white lysozyme (HEWL) as a test case.
- The resulting electron-density map provided high-quality data that enabled solid model refinement, achieving a final R value of 17.4%, and assessed the minimum number of phased reflections necessary for accurate map interpretation.
Article Abstract
In a previous communication [Weckert et al. (1999). Acta Cryst. D55, 1320-1328], the feasibility of the measurement of a large set of triplet phases by three-beam interference was demonstrated. This paper reports the methodology for the calculation of an electron-density map from this limited amount of experimental phase information and the map's properties with respect to model building and refinement. The tetragonal form of hen egg-white lysozyme (HEWL) was chosen as a test structure for the development of this method. The quality of the electron-density map obtained from all measured triplet phases allows a straightforward and nearly complete interpretation. The starting model was refined to a final R value of 17.4%. In a second step, the minimum number of phased reflections needed for the interpretation of an electron-density map was investigated, applying criteria based on |F| and resolution.
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| http://dx.doi.org/10.1107/s0907444999016716 | DOI Listing |
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