FEM: feature‐enhanced map. (1st March 2015)

• Record Type: Journal Article
• Authors: Afonine, Pavel V.; Moriarty, Nigel W.; Mustyakimov, Marat; Sobolev, Oleg V.; Terwilliger, Thomas C.; Turk, Dusan; Urzhumtsev, Alexandre; Adams, Paul D.
• Is Part Of: Acta crystallographica. Volume 71:Part 3(2015:Mar.)
• Page Start: 646
• Page End: 666
• Publication Date: 2015-03-01
• Subjects: Biomolecules -- Structure -- Periodicals; Physical biochemistry -- Periodicals; X-ray crystallography -- Periodicals; Crystallography -- Periodicals; 572
• DOI: 10.1107/S1399004714028132
• Languages: English
• ISSNs: 0907-4449

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A method is presented that modifies a 2<italic>m</italic><bold>F</bold>_obs−<italic>D</italic><bold>F</bold>_modelσ_A‐weighted map such that the resulting map can strengthen a weak signal, if present, and can reduce model bias and noise. The method consists of first randomizing the starting map and filling in missing reflections using multiple methods. This is followed by restricting the map to regions with convincing density and the application of sharpening. The final map is then created by combining a series of histogram‐equalized intermediate maps. In the test cases shown, the maps produced in this way are found to have increased interpretability and decreased model bias compared with the starting 2<italic>m</italic><bold>F</bold>_obs−<italic>D</italic><bold>F</bold>_modelσ_A‐weighted map.</p> </abstract>