Hi All,

I am currently trying to filter a CCP4-formatted real space map from the EMDB, which is at 3.2 Å resolution, to different resolutions from 3.2 to 5 Å, and I've been having a bit of a difficult time getting it to work.

My first thought was to do an fft to get structure factors, then regenerate the map from those structure factors with a resolution cutoff. To do this, I used the tools "phenix.map_to_structure_factors" and "phenix.mtz2map" to generate a structure factor file, then convert it back into a map. When I do this, I end up with a very noisy map that is not usable for what I would like to do.

Is there a better way to accomplish this in phenix (or another tool)? I've also tried some low-pass filtering with proc3d, without much success...

Thanks,
Ben Barad
Fraser Lab @ UCSF