Just use P1 and "ncs" constraints. What's the problem? Or just keep entire map and have only symmetry independent copy to work with until finishes, then make the whole molecule. For real-space refinement it's totally irrelevant whether you have whole molecule or 1/Nth of it. So.. it isn't clear what the problem is..

Pavel

On Thu, May 18, 2017 at 10:06 PM, Qingfeng Chen <[log in to unmask]> wrote:

Hi,

I have an EM map of a tetrameric protein. It was painful to work with this map since it is in P1 spacegroup, although 4-fold symmetry was already applied during map reconstruction.

I noticed that people used MAPMAN to transform spacegroup, however, it seems not working for me. The map remained in P1 spacegroup afterwards.

I used mtz file converted from .mrc and the tetrameric protein model as input and choose "run fft to generate simple map". I also specified "output map in ccp4 format to cover all atoms in pdb". In "infrequently used options", I input P4 in "generate map in spacegroup". Everything else was left as default.

Any suggestions will be appreciated.

Thanks!