Sunday, 1 April 2012

Restrained refinement problem

From: Dipankar Manna
Date: 12 March 2012 05:21


Dear All,

 

As I am practicing new in the crystallography, I am facing some difficulties in refining the ligand bound structure. Protein I am working with has SG P212121, it's a dimer. I fitted the ligand on the density with COOT-->calculate-->Model/Fit/Refine-->Rotate/Translate Zone. Then I merged both (protein & ligand) the pdb structure and saved the coordinate as .pdb file. By taking this pdb when I am running restrained refinement it was showing:

 

Number of atoms    :    2508

  Number of residues :     319

  Number of chains   :       3

  I am reading library. Please wait.

                mon_lib.cif

  WARNING : link:SS       is found dist =     2.026 ideal_dist=     2.031

            ch:AA   res:  15  CYS      at:SG  .->AA   res:  29  CYS      at:SG  .

  WARNING : link:SS       is found dist =     2.069 ideal_dist=     2.031

            ch:AA   res:  30  CYS      at:SG  .->AA   res:  43  CYS      at:SG  .

  WARNING : link:SS       is found dist =     2.031 ideal_dist=     2.031

            ch:AA   res:  33  CYS      at:SG  .->AA   res:  52  CYS      at:SG  .

……………………………………………………………………………………………………………………………………………………………….

PDB_code:xxxx

  PDB_name:----

  PDB_date:XX-XXX-9-

  --------------------------------

  ATTENTION: atom:CD   LYS        75  BB   is missing in the structure

  ATTENTION: atom:CE   LYS        75  BB   is missing in the structure

  ATTENTION: atom:NZ   LYS        75  BB   is missing in the structure

……………………………………………………………………………………………………………………………………………………………………………………………………….

ERROR : atom :C1   LIG       900  CC   is absent in the library

  ERROR : atom :O1   LIG       900  CC   is absent in the library

  ERROR : atom :C2   LIG       900  CC   is absent in the library

  ERROR : atom :C3   LIG       900  CC   is absent in the library

 

In the next cycle I put the .cif (newly generated) as LIB in, and rerun the job. Again it was showing some error like:

 

Number of atoms    :    2508

  Number of residues :     319

  Number of chains   :       3

  I am reading library. Please wait.

                mon_lib.cif

  WARNING : residue: LIG       900  chain:CC

            atom: "C28 " is absent in coord_file

            atom: "C26 " is absent in coord_file

            atom: "C24 " is absent in coord_file

            atom: "C1  " is absent in lib description.

            atom: "O1  " is absent in lib description.

            atom: "C2  " is absent in lib description.

………………………………………………………………………………………………………………………………………………………………………………………….

WARNING : LIG      : program can not match library description....

                    program will create complete description for:LIG

 * Plotfile: C:\Ccp4Temp\refmac5_temp1.01004_new_LIG_N1.ps

  WARNING : residue: LIG       900  chain:CC   - rename

           "LIG     " --> "LIG_N1  "

  WARNING : link:SS       is found dist =     2.026 ideal_dist=     2.031

            ch:AA   res:  15  CYS      at:SG  .->AA   res:  29  CYS      at:SG  .

--------------------------------------------------------------------------------------------------------------------------------

PDB_code:xxxx

  PDB_name:----

  PDB_date:XX-XXX-9-

  --------------------------------

  ATTENTION: atom:CD   LYS        75  BB   is missing in the structure

  ATTENTION: atom:CE   LYS        75  BB   is missing in the structure

  ATTENTION: atom:NZ   LYS        75  BB   is missing in the structure

  ATTENTION: atom:CD   LYS        78  BB   is missing in the structure

---------------------------------------------------------------------------------------------------------------------------

Important, Important, Important!!!!!

 

Your coordinate file has a ligand which has either minimum or no description in the library

A new ligand description has been added to H:/DATA/TR/020312_C5/TR_8_lib.cif

Picture of the new ligand can be viewed using postscript file. See above

Check description in this file and, if satisfied, use it as the input library

Otherwise either edit bond orders manually or use CCP4i Sketcher to view and edit the ligand

and create a library entry by running libcheck

It is strongly recommended that dictionary  entry should be checked carefully before using it

If you are happy with the library description then use the keyword (MAKE CHECK NONE)

I.e. do not check correctness of the coordinates

===> Error: New ligand has been encountered. Stopping now

<B><FONT COLOR="#FF0000"><!--SUMMARY_BEGIN-->

 Refmac_5.6.0117:  New ligand has been encountered. Stopping now

Times: User:       0.0s System:    0.0s Elapsed:     0:23 

</pre>

</html>

<!--SUMMARY_END--></FONT></B>

***************************************************************************

* Information from CCP4Interface script

***************************************************************************

The program run with command: refmac5 XYZIN "H:/DATA/TR/020312_C5/tn_2.1_ref1_molrep1_refmac1-coot-0.pdb" XYZOUT "H:/DATA/TR/020312_C5/tn_2.1_ref1_molrep1_refmac2.pdb" HKLIN "H:/DATA/TR/020312_C5/tn020312_c5_refmac2.mtz" HKLOUT "H:/DATA/TR/020312_C5/tn020312_c5_refmac4.mtz" LIBOUT "H:/DATA/TR/020312_C5/TR_8_lib.cif"

has failed with error message

 Refmac_5.6.0117:  New ligand has been encountered. Stopping now

***************************************************************************

 

 

#CCP4I TERMINATION STATUS 0  Refmac_5.6.0117:  New ligand has been encountered. Stopping now

#CCP4I TERMINATION TIME 12 Mar 2012  08:30:36

#CCP4I TERMINATION OUTPUT_FILES  H:/DATA/TR/020312_C5/TR_8_lib.cif TR

 

Please give me some suggestuion.

 

Regards,

 

Dipankar



----------
From: Laurent Maveyraud


Hi,

did you check in the refmac logfile that the cif file created at the first step was actually read ?
If it is, you will have to carefully check the cif file and you ligand structure :
1) is the ligand structure included in the PDB at the fisrt step complete ?? Maybe you included only a partial lignad because of weak density... when you add other atoms, they will be missing from the cif file.
2) are all the ligand atoms present in the cif file with correct names ?
3) are the information present in the cif file correct (connectivity, bond order, planar group, chiral center). This will not produce the error you have, but will certainly distort the geometry...

hope this helps

laurent

Le 12/03/2012 06:21, Dipankar Manna a écrit :
--
----------------------------------------------------------
Laurent Maveyraud         

----------
From: Tim Gruene


Dear Dipankar,

according to the log-file, the restraints-file was not read in the
second time you ran refmac5. It should otherwise be listet in the
section underneath "Information from CCP4Interface script" where it is
mentioned as "LIBOUT" instead of "LIBIN". Can you confirm the you added
the cif-file as "LIB in" in the ccp4i GUI and not "Output lib"?

Regards,
Tim

On 03/12/2012 06:21 AM, Dipankar Manna wrote:
> Dear All,
>
> As I am practicing new in the crystallography, I am facing some difficulties in refining the ligand bound structure. Protein I am working with has SG P212121, it's a dimer. I fitted the ligand on the density with COOT-->calculate-->Model/Fit/Refine-->Rotate/Translate Zone. Then I merged both (protein & ligand) the pdb structure and saved the coordinate as .pdb file. By taking this pdb when I am running restrained refinement it was showing:
>
> Number of atoms    :    2508
>   Number of residues :     319
>   Number of chains   :       3
>   I am reading library. Please wait.
>                 mon_lib.cif
>   WARNING : link:SS       is found dist =     2.026 ideal_dist=     2.031
>             ch:AA   res:  15  CYS      at:SG  .->AA   res:  29  CYS      at:SG  .
>   WARNING : link:SS       is found dist =     2.069 ideal_dist=     2.031
>             ch:AA   res:  30  CYS      at:SG  .->AA   res:  43  CYS      at:SG  .
>   WARNING : link:SS       is found dist =     2.031 ideal_dist=     2.031
>             ch:AA   res:  33  CYS      at:SG  .->AA   res:  52  CYS      at:SG  .
> .....................................................................................................................................................................................
> PDB_code:xxxx
>   PDB_name:----
>   PDB_date:XX-XXX-9-
>   --------------------------------
>   ATTENTION: atom:CD   LYS        75  BB   is missing in the structure
>   ATTENTION: atom:CE   LYS        75  BB   is missing in the structure
>   ATTENTION: atom:NZ   LYS        75  BB   is missing in the structure
> ..................................................................................................................................................................................................................................
> ERROR : atom :C1   LIG       900  CC   is absent in the library
>   ERROR : atom :O1   LIG       900  CC   is absent in the library
>   ERROR : atom :C2   LIG       900  CC   is absent in the library
>   ERROR : atom :C3   LIG       900  CC   is absent in the library
>
> In the next cycle I put the .cif (newly generated) as LIB in, and rerun the job. Again it was showing some error like:
>
> Number of atoms    :    2508
>   Number of residues :     319
>   Number of chains   :       3
>   I am reading library. Please wait.
>                 mon_lib.cif
>   WARNING : residue: LIG       900  chain:CC
>             atom: "C28 " is absent in coord_file
>             atom: "C26 " is absent in coord_file
>             atom: "C24 " is absent in coord_file
>             atom: "C1  " is absent in lib description.
>             atom: "O1  " is absent in lib description.
>             atom: "C2  " is absent in lib description.
> ...................................................................................................................................................................................................................
- --
- --
Dr Tim Gruene

1 comment:

  1. I have same problem and nothing solved yet have any other comments or suggestions?

    ReplyDelete