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[ccp4bb] PHENIX & BSS refinement

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999
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Subject: Re: difficult MAD dataset
From: "Stephen Graham stepheng {- at -} strubi {- dot -} ox {- dot -} ac {- dot -} uk
Date: 2009-02-03
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Subject: PHENIX & BSS refinement
From: Jose Casasnovas jcasasnovas {- at -} CNB {- dot -} CSIC {- dot -} ES
Date: 2009-02-03



We have seen that the recent versions of phenix (1.3) the structure
refinement ends with a bulk solvent correction step, something I found
quite unusual (absent in other refinement programs and in older versions
of phenix, 1.24.1).  We have also seen that the B factor jumps up in
this last step (see bellow).  Is anybody aware of this?  Do you
know how to get rid of this final bss step?  This step is redundant,
as bss is also done at the beginning of each ref cycle.


Header of a pdb file after refinement with phenix version 1.3:


REMARK  R-factors, x-ray target values and norm of gradient of x-ray
target

REMARK  stage     r-work r-free 
xray_target_w  xray_target_t

REMARK    0    :  0.3729
0.3776   5.594260e+00   5.604698e+00

REMARK    1_bss:  0.3135 0.3236  
5.460255e+00   5.490057e+00   BSS refinement
step

REMARK    1_xyz:  0.3096 0.3226  
5.451384e+00   5.487128e+00   refinement of
coordinates 

REMARK    1_adp:  0.2608 0.2858  
5.300551e+00   5.386607e+00   refinement of ADPs


REMARK    2_bss:  0.2601 0.2843  
5.299065e+00   5.384776e+00

REMARK    2_xyz:  0.2545 0.2847  
5.285488e+00   5.386100e+00

REMARK    2_adp:  0.2460 0.2821  
5.261319e+00   5.375879e+00

REMARK    3_bss:  0.2456 0.2788  
5.257944e+00   5.366116e+00

REMARK    3_xyz:  0.2457 0.2809  
5.261113e+00   5.371113e+00

REMARK    3_adp:  0.2427 0.2804  
5.252685e+00   5.370838e+00

REMARK    3_bss:  0.2427 0.2804  
5.252685e+00   5.370838e+00  ???????????


Bfactors

REMARK  stage      b_max  
b_min   b_ave

REMARK    0    :  
30.00   30.00   30.00

REMARK    1_bss:   30.00  
30.00   30.00

REMARK    1_xyz:   30.00  
30.00   30.00

REMARK    1_adp:  118.26   
1.18   35.04

REMARK    2_bss:  118.26   
1.18   35.04

REMARK    2_xyz:  118.26   
1.18   35.04

REMARK    2_adp:  157.72   
0.00   37.99

REMARK    3_bss:  157.72   
0.00   37.99

REMARK    3_xyz:  157.72   
0.00   37.99

REMARK    3_adp:  166.60   
0.00   38.73

REMARK    3_bss:  203.00  
36.40   75.12 ??????


Thanks a lot for your help.


Jose M Casasnovas


Centro Nacional de Biotecnología (lab. B16)

CSIC, Campus UAM

Darwin 3

28049 Madrid

Spain

Ph.  34 915854917(8)

Fax. 34 915854506

email: jcasasnovas@cnb.csic.es   !!!!!! NEW E-MAIL





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