With such a lot of molecules, I would check for oligamers. Look at the MOLREP self rotation - is there anything obvious? Send the*.ps if you like and I can comment.
And do the models form oligimers? If so search with that.. Eleanor And as Randy says - try PHASER .. On 31 October 2016 at 21:30, Randy Read <[email protected]> wrote: > Dear Alex, > > We’ve had very good luck using Phaser to place large numbers of copies of > good models. It’s in this kind of case where the increased sensitivity of > the likelihood approach really helps. I would suggest trying the different > choices of model as alternatives, and you might also want to make an > ensemble in which loops that deviate among the different models have been > trimmed off. > > If you need more advice on how to do this, you can get in touch off-line. > > Best wishes, > > Randy Read > > ----- > Randy J. Read > Department of Haematology, University of Cambridge > Cambridge Institute for Medical Research Tel: +44 1223 336500 > Wellcome Trust/MRC Building Fax: +44 1223 336827 > Hills Road > E-mail: [email protected] > Cambridge CB2 0XY, U.K. > www-structmed.cimr.cam.ac.uk > > > On 31 Oct 2016, at 18:16, Alex Lee <[email protected]> wrote: > > > > Hi All, > > > > I have a protein which contains 72 amino acids. The crystal of this > protein diffracts to 2.5A with SG P31 (CELL Dimension 65.9590 65.9590 > 164.3900 90.0000 90.0000 120.0000). Pointless indicates no twinning. > > > > Mathew coefficient as below: > > For estimated molecular weight 7919. > > Nmol/asym Matthews Coeff %solvent P(2.49) P(tot) > > _____________________________________________________________ > > 1 26.07 95.29 0.00 0.00 > > 2 13.04 90.57 0.00 0.00 > > 3 8.69 85.86 0.00 0.00 > > 4 6.52 81.14 0.00 0.00 > > 5 5.21 76.43 0.00 0.00 > > 6 4.35 71.71 0.00 0.01 > > 7 3.72 67.00 0.02 0.02 > > 8 3.26 62.28 0.05 0.05 > > 9 2.90 57.57 0.11 0.11 > > 10 2.61 52.85 0.19 0.19 > > 11 2.37 48.14 0.25 0.25 > > 12 2.17 43.42 0.22 0.22 > > 13 2.01 38.71 0.11 0.12 > > 14 1.86 33.99 0.03 0.03 > > 15 1.74 29.28 0.00 0.00 > > 16 1.63 24.56 0.00 0.00 > > 17 1.53 19.85 0.00 0.00 > > 18 1.45 15.13 0.00 0.00 > > 19 1.37 10.42 0.00 0.00 > > 20 1.30 5.70 0.00 0.00 > > 21 1.24 0.99 0.00 0.00 > > _____________________________________________________________ > > > > I have at least 10 structures in PDB with homology 60% or above. > > I tried the CCP4online MrBump and Balbes for automatic molecular > replacement. No solutions at all. > > I do not know if this is because that the high number of copies in ASU > (maybe 10 copies as shown by Mathew coefficient) hamper the MrBump and > Balbes to do MR? > > > > Dose anyone experience similar difficulties with high number of copies > to do automatic MR? > > > > Thanks ahead! >
