The model to map fsc strange because a extra bump in FSC

Hi all,

I’ve been getting this extra bump (around 6Å) in my FSCs from my dataset.


When I caculate the FSC between map to model,I get drop too,so when I choose 0.5 to get the resolution is far away from 3.5 like below.(1.add a mask didn’t have soft pading.2.add a soft padding but this fsc have a big drop.)

How can I solve this problem?Or there is some possible mistake in my processing steps.Thanks all advance.

Could it be that you are working on a membrane protein (with micelle)? Or does your structure have another flexible region in it? To me it looks like there are virtually two FSC curves overlayed. One low res curve for a part of your protein that has a resolution around ~ 5.8A and a high res part that should show up in your structure as secondary structure features (the second FSC bump).

If this is the case you could try refining the two parts separately and check whether you get rid of the bump :slight_smile:

Happy processing!