DENSS v1.6.1 now includes new convenience features to automatically estimate the maximum dimension of the particle, Dmax, and perform fitting of the experimental scattering profile. denss.fit_data.py will automatically estimate Dmax when started and calculate an initial profile fit, rather than default to Dmax = 100 Ådenss.fit_data.py will now write out additional header lines to the *_fit.dat output file containing parameter values such as Dmax and Rg.denss.py now reads the header from … [Read more...]

Version 1.6 contains several updates, features and bug fixes since DENSS version 1.5.0. Special thanks to Jesse Hopkins, Andrew Bruno, and Markus Meier and Fabian Heide for bug fixes and improvements. Some major updates include: GPU acceleration added (v1.5.1) (requires CuPy and CUDA GPU)Major updates to how shrink-wrap deals with negative contrast, particularly important for membrane proteins and other lipid containing particlesSeveral updates to denss.fit_data.py Some additional updates … [Read more...]

A new --gpu option when running denss.py v1.5.1 with NVIDIA CUDA capable graphics cards is available. Tests show this option speeds DENSS up by more than 20x compared to CPU-only. Requires CuPy to be installed. We will attempt to update this in the future for more GPUs using OpenCL. Please contact us to let us know if you run into any bugs or issues. … [Read more...]

The major new update includes: DENSS updated to Python 3 Some additional updates include: added pdb2map_fastgauss() function which is >100x faster for calculating density from PDB atomic coordinatesfixed bugs in denss.mrcops.py related to resampling and rescalingfixed bug with origin definition when writing MRC files. Now compatible with latest versions of PyMOL … [Read more...]

DENSS now has a new mode for membrane proteins. Membrane proteins are often solubilized in detergents or lipid nanodiscs. The hydrophobic regions of these molecules often have lesser scattering density than the bulk solvent, resulting in a negative contrast relative to the solvent. The default setting for DENSS enforces a positivity restraint that will not allow any density to be negative. While this is appropriate for most standard biomolecules such as proteins and nucleic acids, is it not … [Read more...]

DENSS now includes the ability to impose symmetry to improve the resolution of reconstructions. DENSS first aligns the principal axes of the map with the x, y, and z axes. Then the value of the map at each symmetry mate location is set to the average of all related values. Imposing symmetry is as easy as setting the -ncs option. Click here to learn more.  … [Read more...]

DENSS now has a new built-in averaging procedure since v1.4.4. The alignment works by first performing a coarse-grained rotational search uniformly sampled around a sphere to find the best coarse alignment. Then a fine alignment is performed using minimization including rotational and translational degrees of freedom. Enantiomer generation and selection is included, as well as the use of a binary tree algorithm for creating a reference volume for alignment. Previously averaging was dependent … [Read more...]

Three new scripts have been uploaded to the DENSS github repository. These scripts include: the ability to fit smooth functions to noisy experimental data (required for denss.py input), calculate scattering profiles from electron density maps, and calculate electron density maps from PDB files. The new scripts include: denss.fit_data.py fit a smooth curve to experimental data and calculate the corresponding P(r) (pair distribution function) includes convenient interactive GUI … [Read more...]