Hi,

This is a case of small protein packed in P1. One question may be raised if you have all molecules added to your model? Based on the cell constants and the information of ~60 residues you provided, the solvent content is ~70%, which is not that normal for a small unit cell (18 Å or so), although the Matthews Coefficient calculation may be less accurate. I would check the solvent region! With 4 moles in this P1 cell, the solvent content could be ~36%, which is very normal for small-mol in small cell. If it is true (2 mols in P1) to have such a high solvent content, a Babinet scaling in Refmac may help lower Rs.

Also, the Rfree of the highest resolution shell is >60%, which means you may need rethink about the resolution cutoff. According to Wilson's statistics (1950), it is problematic in this model.

Can also you show the statistics when data was processed in P2/P21, though I do not think P1 refinement should be the cause of such high Rs.

Best luck!

Lijun

On Jul 19, 2010, at 12:41 AM, 孙庆祥 wrote:

Dear Collins and all,

Thanks for the reply. Please find the following pdb header. For your information, this is after refmac5 with twin-refinement option selected. This is the best R values that I'm getting. Cutting resolution does not help much in getting the Rs down...


HEADER    SWISS-MODEL SERVER (                    pa-JAN-g)   XXXX
COMPND    SS-MODEL
REMARK   3
REMARK   3 REFINEMENT.
REMARK   3   PROGRAM     : REFMAC 5.5.0109
REMARK   3   AUTHORS     : MURSHUDOV,VAGIN,DODSON
REMARK   3
REMARK   3    REFINEMENT TARGET : MAXIMUM LIKELIHOOD
REMARK   3
REMARK   3  DATA USED IN REFINEMENT.
REMARK   3   RESOLUTION RANGE HIGH (ANGSTROMS) :   1.52
REMARK   3   RESOLUTION RANGE LOW  (ANGSTROMS) :  74.96
REMARK   3   DATA CUTOFF            (SIGMA(F)) : NONE
REMARK   3   COMPLETENESS FOR RANGE        (%) :  91.56
REMARK   3   NUMBER OF REFLECTIONS             :   27851
REMARK   3
REMARK   3  FIT TO DATA USED IN REFINEMENT.
REMARK   3   CROSS-VALIDATION METHOD          : THROUGHOUT
REMARK   3   FREE R VALUE TEST SET SELECTION  : RANDOM
REMARK   3   R VALUE     (WORKING + TEST SET) : 0.42077
REMARK   3   R VALUE            (WORKING SET) :  0.42170
REMARK   3   FREE R VALUE                     :  0.40609
REMARK   3   FREE R VALUE TEST SET SIZE   (%) :  5.4
REMARK   3   FREE R VALUE TEST SET COUNT      :  1584
REMARK   3
REMARK   3  FIT IN THE HIGHEST RESOLUTION BIN.
REMARK   3   TOTAL NUMBER OF BINS USED           :      20
REMARK   3   BIN RESOLUTION RANGE HIGH           :    1.522
REMARK   3   BIN RESOLUTION RANGE LOW            :    1.561
REMARK   3   REFLECTION IN BIN     (WORKING SET) :     1804
REMARK   3   BIN COMPLETENESS (WORKING+TEST) (%) :    82.44
REMARK   3   BIN R VALUE           (WORKING SET) :    0.529
REMARK   3   BIN FREE R VALUE SET COUNT          :      121
REMARK   3   BIN FREE R VALUE                    :    0.622
REMARK   3
REMARK   3  NUMBER OF NON-HYDROGEN ATOMS USED IN REFINEMENT.
REMARK   3   ALL ATOMS                :      984
REMARK   3
REMARK   3  B VALUES.
REMARK   3   FROM WILSON PLOT           (A**2) : NULL
REMARK   3   MEAN B VALUE      (OVERALL, A**2) :  18.096
REMARK   3   OVERALL ANISOTROPIC B VALUE.
REMARK   3    B11 (A**2) :     8.45
REMARK   3    B22 (A**2) :   -12.86
REMARK   3    B33 (A**2) :     4.41
REMARK   3    B12 (A**2) :     0.51
REMARK   3    B13 (A**2) :    -1.32
REMARK   3    B23 (A**2) :    -8.65
REMARK   3
REMARK   3  ESTIMATED OVERALL COORDINATE ERROR.
REMARK 3 ESU BASED ON R VALUE (A): 0.032 REMARK 3 ESU BASED ON FREE R VALUE (A): 0.026 REMARK 3 ESU BASED ON MAXIMUM LIKELIHOOD (A): 0.082 REMARK 3 ESU FOR B VALUES BASED ON MAXIMUM LIKELIHOOD (A**2): 5.306
REMARK   3
REMARK   3 CORRELATION COEFFICIENTS.
REMARK   3   CORRELATION COEFFICIENT FO-FC      :   0.812
REMARK   3   CORRELATION COEFFICIENT FO-FC FREE :   0.853
REMARK   3
REMARK 3 RMS DEVIATIONS FROM IDEAL VALUES COUNT RMS WEIGHT REMARK 3 BOND LENGTHS REFINED ATOMS (A): 1016 ; 0.008 ; 0.022 REMARK 3 BOND ANGLES REFINED ATOMS (DEGREES): 1382 ; 1.482 ; 1.974 REMARK 3 TORSION ANGLES, PERIOD 1 (DEGREES): 122 ; 9.603 ; 5.000 REMARK 3 TORSION ANGLES, PERIOD 2 (DEGREES): 46 ;33.363 ; 26.087 REMARK 3 TORSION ANGLES, PERIOD 3 (DEGREES): 176 ;21.472 ; 15.000 REMARK 3 TORSION ANGLES, PERIOD 4 (DEGREES): 2 ;13.956 ; 15.000 REMARK 3 CHIRAL-CENTER RESTRAINTS (A**3): 144 ; 0.102 ; 0.200 REMARK 3 GENERAL PLANES REFINED ATOMS (A): 774 ; 0.007 ; 0.022
REMARK   3
REMARK 3 ISOTROPIC THERMAL FACTOR RESTRAINTS. COUNT RMS WEIGHT REMARK 3 MAIN-CHAIN BOND REFINED ATOMS (A**2): 624 ; 0.917 ; 1.500 REMARK 3 MAIN-CHAIN ANGLE REFINED ATOMS (A**2): 1020 ; 1.686 ; 2.000 REMARK 3 SIDE-CHAIN BOND REFINED ATOMS (A**2): 392 ; 1.691 ; 3.000 REMARK 3 SIDE-CHAIN ANGLE REFINED ATOMS (A**2): 362 ; 2.734 ; 4.500
REMARK   3
REMARK 3 ANISOTROPIC THERMAL FACTOR RESTRAINTS. COUNT RMS WEIGHT REMARK 3 RIGID-BOND RESTRAINTS (A**2): 1016 ; 0.952 ; 3.000
REMARK   3
REMARK   3  NCS RESTRAINTS STATISTICS
REMARK   3   NUMBER OF NCS GROUPS : NULL
REMARK   3
REMARK   3  TWIN DETAILS
REMARK   3   NUMBER OF TWIN DOMAINS  :    4
REMARK   3      TWIN DOMAIN   :    1
REMARK   3      TWIN OPERATOR :  H,  K,  L
REMARK   3      TWIN FRACTION : 0.307
REMARK   3      TWIN DOMAIN   :    2
REMARK   3      TWIN OPERATOR : -H,  K, -K-L
REMARK   3      TWIN FRACTION : 0.191
REMARK   3      TWIN DOMAIN   :    3
REMARK   3      TWIN OPERATOR : -H, -K,  K+L
REMARK   3      TWIN FRACTION : 0.198
REMARK   3      TWIN DOMAIN   :    4
REMARK   3      TWIN OPERATOR :  H, -K, -L
REMARK   3      TWIN FRACTION : 0.304
REMARK   3
REMARK   3
REMARK   3  TLS DETAILS
REMARK   3   NUMBER OF TLS GROUPS  : NULL
REMARK   3
REMARK   3
REMARK   3  BULK SOLVENT MODELLING.
REMARK   3   METHOD USED :  MASK
REMARK   3   PARAMETERS FOR MASK CALCULATION
REMARK   3   VDW PROBE RADIUS   :   1.40
REMARK   3   ION PROBE RADIUS   :   0.80
REMARK   3   SHRINKAGE RADIUS   :   0.80
REMARK   3
REMARK   3  OTHER REFINEMENT REMARKS:
REMARK   3  HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
REMARK   3  U VALUES      : REFINED INDIVIDUALLY
REMARK   3
SSBOND   1 CYS A    3    CYS A   24
SSBOND   2 CYS A   17    CYS A   41
SSBOND   3 CYS A   43    CYS A   54
SSBOND   4 CYS A   55    CYS A   60
SSBOND   5 CYS B    3    CYS B   24
SSBOND   6 CYS B   17    CYS B   41
SSBOND   7 CYS B   43    CYS B   54
SSBOND   8 CYS B   55    CYS B   60
CRYST1   18.232   39.633   77.526 104.82  90.08  90.04 P 1
SCALE1      0.054849  0.000038  0.000087        0.00000
SCALE2      0.000000  0.025232  0.006677        0.00000
SCALE3      0.000000  0.000000  0.013343        0.00000



>when you say that the Rfree is 0.4, what statistic are you quoting? For all of your data or the highest shell It is clear from the data reduction statistics that your data do not go to 1.57 angstroms. There are no data at that resolution. The <I> is 1/2 of the error; <I> 24 and error about 40. The Rmerge for the shell is 59% which is close enough to random for me to have little confidence in it. >It would help us if you just cut and paste the statistics into the question. >You are right, the density looks great. There is something funny about the statistics if this is a normal 2fo-fc map.
>cheers,
>-ed collins
>
>On Jul 18, 2010, at 10:39 PM, 孙庆祥 wrote:
>
>> <Density over model.png>
>


您想拥有和网易免费邮箱一样强大的软件吗?

Lijun Liu
Cardiovascular Research Institute
University of California, San Francisco
1700 4th Street, Box 2532
San Francisco, CA 94158
Phone: (415)514-2836



Reply via email to