Dear all, Recently, I've gotten a 3.1A data set with a P1 space group. Based on a Mattchew coefficient, I have 4 hetero-dimer molecules in one asymmetric unit. Because one of the dimers was known already, I tried MR with a program Phaser and molrep (Amore doesn't calculate a translation function with a P1 space group). Phaser gave me a reasonable solution with Z-score closed to 20 and LL-gain over 900(molrep didn't give me a good solution), and that solution has 4 molecules with quite reasonable packing with local 2-fold symmetries. I also ran Phaser with different wavelength ranges with different truncated forms, and always the solutions were the same. However, when I calculated the map, the map was still messy and I couldn't see a clear density of the other molecules. I also ran a rigid body refinement and a restrained refinement with different programs (refmac and cns), but the R factor didn't drop. I ran DM with ncs averaging and solvent flattening, still the map wasn't improved. At this moment, we are still sure that our data set has a P1 space group with good statistics and the solution from phaser is quite reasonable.
Is it possible that P1 space group can be a problem during MR? Do you think the solution from Phaser is just wrong or did I miss something? Any suggestions will be helpful to me. Thanks, uhnsoo
