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On Sun, 2006-10-22 at 14:47 +0100, Thomas Edwards wrote: > I have a high resolution native data set (1.7A) and a decent model for MR > (35% identity over 70 residues, 100 residues total in ASU). Data scales well > in P 3 2 1 (but not P6), and there are absences indicating a screw axis along > the 3-fold. > > I'm trying MR with Phaser using data from 15 - 3.0 A. There's no need to truncate the data, unless there is a known problem. Phaser will weight and truncate the data as appropriate for each step (usually high-res limit of 2.5A for FRF and FTF). So giving it all the data may help a little. > > Phaser does not produce solutions with Z scores over 5 for P 3 2 1 or P 31 2 > 1. > However, in P 32 2 1 there is a solution with Z score of 8.57. A part of the > .sum file is attached below. The 2 solutions written out from set 1 trial 3 > both have high Rfactors in a rigid body refinement (over 55%), so I'm > assuming that is not a correct solution. I wouldn't give up too quickly. At 1.7A, the lazy thing to do is throw the solution at arp/warp and see what happens. It might be OK. Cheers Martyn > I tried the MR protocol is CNS. The cross rotation function scores look good, > but not the translation function scores and the top solutions all have > Rfactors over 55%. > > There is no evidence of twinning. > > So... can anybody point me to something else I should look at/try? > Also - why is there no "third" solution for set 1 trial 3? > > Thanks > Ed > > _____________ > T.Edwards Ph.D. > Astbury Centre for Structural Molecular Biology > Institute of Molecular Cell Biology > University of Leeds > LS2 9JT > 0113 343 3031 > > > --------------- > FINAL SELECTION > --------------- > > Mean (Sigma) used for final selection = -32.702 (9.68956) > Number of solutions stored before final selection = 323 > Number of solutions stored (deleted) after final selection = 2 (321) > > Fast Translation Function Table: Space Group P 32 2 1 > ----------------------------------------------------- > #SET #TRIAL Top (Z) Second (Z) Third (Z) Ensemble > 1 1 14.41 ( 4.59) 13.05 ( 4.45) 11.37 ( 4.28) ensemble1 > 1 2 13.47 ( 4.69) 12.79 ( 4.62) 11.10 ( 4.44) ensemble1 > 1 3 53.02 ( 8.57) 33.72 ( 6.65) - - ensemble1 > 1 4 22.73 ( 5.34) 19.07 ( 4.99) 17.93 ( 4.88) ensemble1 > 1 5 15.38 ( 4.76) 11.80 ( 4.39) 11.07 ( 4.32) ensemble1 > 1 6 9.45 ( 4.57) 8.01 ( 4.42) 7.56 ( 4.37) ensemble1 > 1 7 11.65 ( 5.05) 10.91 ( 4.97) 10.02 ( 4.87) ensemble1 > 1 8 9.86 ( 4.73) 8.45 ( 4.57) 7.70 ( 4.49) ensemble1 > ---- ------ >
