Electron density maps: Difference between revisions

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Eric Martz (talk | contribs)
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[[Image:Plant Physiology 76 175.JPG|thumb|right]]
[[Image:Plant Physiology 76 175.JPG|thumb|right]]
Electron density values fill 3-dimensional space of the map (see this [http://www.bioinformatics.org/molvis/edm/ interactive visualization]). The term "map" is historical; the three-dimensional electron density was plotted on several pages, section by section, with contour lines corresponding to the value of the density at that location. These plots were called a map, in reference to topographical maps. For a paper showing several examples of maps printed in sections and overlayed, see [https://www.pnas.org/content/pnas/72/12/4866.full.pdf a paper on tRNA structure].
Electron density values fill the 3-dimensional space of the map (see this [http://www.bioinformatics.org/molvis/edm/ interactive visualization]). The term "map" is historical; the three-dimensional electron density was plotted on several pages, section by section, with contour lines corresponding to the value of the density at that location. These plots were called a map, in reference to topographical maps. For a paper showing several examples of maps printed in sections and overlayed, see [https://www.pnas.org/content/pnas/72/12/4866.full.pdf a paper on tRNA structure].


The standard deviation of all density values, ''sigma'', is used to describe the strength of features in a map. For example, a "3 sigma peak" is a feature that has a density value higher than three sigma over the average value, which typically is set to zero.
The standard deviation of all density values, ''sigma'', is used to describe the strength of features in a map. For example, a "3 sigma peak" is a feature that has a density value higher than three sigma over the average value, which typically is set to zero.