Hi, It soulds like you have serious disorder in the structure. On the subject of twinning - do you have the original diffraction images, and is there enough data to re-process in a lower space group? Sometimes it takes only a few non-symmetrical atoms to break an apparent higher symmetry, in which case there may be issues with twin detection or lower non-apparent symmetry.
The amount of detail you provided isn't sufficient to draw any further conclusions, besides trying lower symmetry. Artem -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Cui Sheng Sent: Monday, June 02, 2008 5:24 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] gfp problem Dear all: We have an unrefinable protein complex structure with one of the component is just a gfp. The space group shows as a P6122, a notorious space group for twining. But I could not detect any sign of twinnig using various of softwares. The R_free traps currently at 0.34 and no more space to impove. We observed only one of the two gfps in ASU is badly fited to the density. In this molecule, there are quite some loops in contact to solution looked totally mesy and all the parts rest looks just fine. Take those mesy loops in to the consideration,account for only 3% residues in ASU we are still bitterly puzzled by the fact that our structure is 5% or more away from a refined structure. Native dataset collected at 2.5A Molecular replacement gives unique solution using normal gfp as searching model. any good ideas solving our problem? many thanx in advance sheng
