We are faced with phasing a structure for a protein that refuses to crystallize in any spacegroup but P1. To add to the fun , the resolution for most selenomethionine and heavy atom soak datasets ranges from 3.8 to 4.2 A .
In order to increase the redundancy we have been taking many inverse beam datasets from each crystal by making sure the beam is significantly attenuated. We now have 360 times 6, ( i.e 6 passes) and in some case 8 passes, datasets for a few crystals collected at the peak wavelength in the case of Selenomethionine crystals. In some cases we even managed an inflection dataset . Needless to say the anomolous signal seems quite week at these resolutions and low redundancies for any single crystal dataset. I was wondering if anyone could comment on combining datasets from multiple P1 crystals to increase the redundancy even further for such heavy atom ( SAS / SAD ) or MAD experiments. Thanks a lot for your help and suggestions in advance hari
