Density Blobs Panel
This panel lists density "blobs"—collections of density peaks from a difference map that are part of a continuous region of density difference.
To open this panel, click Density Blobs in the PrimeX Panel.
- Using
- Features
- Additional Resources
Using the Density Blobs Panel
Density blobs are defined as collections of density peaks from a difference map that are part of a continuous region of density difference, with some minimum value set for determining the continuity of the region. The Ligand/Solvent Placement Panel makes use of density blobs to define the location of the ligand or solvent molecule. The ability to display density blobs may be useful in other contexts.
Before opening the panel, ensure that an Fo-Fc map is displayed in the Workspace. The map is analyzed for density peaks, and peaks that are connected to other peaks (by a saddle point that has a density above a predefined threshold) are joined into "blobs".
Density Blobs Panel Features
- Blobs table
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Table of density blobs computed from the peaks in the current difference map. The blobs are listed in order of volume, which is displayed in the table along with the sign of the difference density. You can select only one blob at a time. When you select a blob in the table, the Workspace view centers on the blob.
- Update button
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Recompute the density blobs from the map and update the table. This button is useful if you generate a difference density map after opening the panel, for example, or make changes in the Workspace.
- Minimum volume to display text box
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The value in this text box sets the cutoff for the volume of the blobs that are displayed in the table. Blobs with volumes smaller than the value set are not displayed.