Hi Robbie,

Oops, sorry, I used
CCP4 6.3: Refmac_5.7.0032     version 5.7.0032 : 05/09/12
(confirmed by the log file)

so I am using the current version and the problem still persists.

Thanks!
Markus


On 18/04/13 03:31 PM, Robbie Joosten wrote:
> Hi Markus,
> 
> You could try changing your Refmac version. The version you are using is 
> ancient. You may have an old version in your
> PATH next to the new one because your CCP4 seems up to date.
> 
> AFAICT there is nothing wrong with the LINKR or the HETATM records
> 
> Sent from my Windows Phone
> ------------------------------------------------------------------------------------------------------------------------
> From: Markus Meier
> Sent: 2013-04-18 22:19
> To: [email protected]
> Subject: [ccp4bb] Alternate sugar conformations in refmac 5.5.0110
> 
> Dear all,
> 
> I am trying to refine a beta-D-N-Acetyl glucosamine moiety (NAG) linked
> to an asparagine (ASN) in Refmac.
> (version CCP4 6.3: Refmac_5.5.0110     version 5.5.0110 : 08/05/10)
> 
> The sugar has two alternate conformations that occupy the same position in 
> the electron
> density but are rotated 180° relative to each other. Even though I have
> defined two alternate conformations for the asparagine side chain, the
> sugar and the beta-link, Refmac pushes the two conformations apart, out of 
> the electron
> density (while still honouring the link to Asn). So it seems that Refmac 
> applies repulsive
> forces between the alternate conformations.
> 
> Did anyone else experience this and/or can suggest a fix?
> All help is very much appreciated!
> 
> My definitions for the alternate conformations in the PDB file are below:
> 
> LINKR        C1 ANAG E   1                 ND2AASN A 116                
> NAG-ASN
> LINKR        C1 BNAG E   1                 ND2BASN A 116                
> NAG-ASN
> HETATM  125  C1 ANAG E   1      30.978  40.626 -25.446  0.50 98.96      E    C
> HETATM  126  C2 ANAG E   1      30.428  41.897 -26.138  0.50100.81      E    C
> HETATM  127  N2 ANAG E   1      29.783  41.751 -27.447  0.50 94.26      E    N
> HETATM  128  C7 ANAG E   1      28.807  42.561 -27.924  0.50 89.45      E    C
> HETATM  129  O7 ANAG E   1      28.325  42.377 -29.035  0.50 83.16      E    O
> HETATM  130  C8 ANAG E   1      28.252  43.720 -27.128  0.50 87.63      E    C
> HETATM  131  C3 ANAG E   1      31.618  42.847 -26.221  0.50102.77      E    C
> HETATM  132  O3 ANAG E   1      31.420  43.888 -27.159  0.50102.25      E    O
> HETATM  133  C4 ANAG E   1      31.840  43.369 -24.802  0.50103.37      E    C
> HETATM  134  O4 ANAG E   1      32.969  44.217 -24.782  0.50104.91      E    O
> HETATM  135  C5 ANAG E   1      32.040  42.223 -23.785  0.50 94.99      E    C
> HETATM  136  C6 ANAG E   1      31.564  42.633 -22.381  0.50 86.60      E    C
> HETATM  137  O6 ANAG E   1      32.632  42.591 -21.462  0.50 77.76      E    O
> HETATM  138  O5 ANAG E   1      31.458  40.954 -24.130  0.50 99.19      E    O
> HETATM  139  C1 BNAG E   1      30.271  40.925 -24.108  0.50 98.96      E    C
> HETATM  140  C2 BNAG E   1      31.415  41.878 -23.684  0.50100.81      E    C
> HETATM  141  N2 BNAG E   1      32.048  41.664 -22.378  0.50 94.26      E    N
> HETATM  142  C7 BNAG E   1      33.331  41.981 -22.079  0.50 89.45      E    C
> HETATM  143  O7 BNAG E   1      33.784  41.778 -20.959  0.50 83.16      E    O
> HETATM  144  C8 BNAG E   1      34.276  42.586 -23.092  0.50 87.63      E    C
> HETATM  145  C3 BNAG E   1      30.816  43.277 -23.775  0.50102.77      E    C
> HETATM  146  O3 BNAG E   1      31.569  44.240 -23.061  0.50102.25      E    O
> HETATM  147  C4 BNAG E   1      30.718  43.597 -25.266  0.50103.37      E    C
> HETATM  148  O4 BNAG E   1      30.115  44.862 -25.440  0.50104.91      E    O
> HETATM  149  C5 BNAG E   1      29.907  42.532 -26.038  0.50 94.99      E    C
> HETATM  150  C6 BNAG E   1      30.373  42.426 -27.500  0.50 86.60      E    C
> HETATM  151  O6 BNAG E   1      29.320  42.743 -28.381  0.50 77.76      E    O
> HETATM  152  O5 BNAG E   1      29.866  41.216 -25.458  0.50 99.19      E    O
> ATOM    745  N   ASN A 116      27.207  36.475 -25.453  1.00 62.15      A    N
> ATOM    746  CA AASN A 116      28.475  37.144 -25.135  0.50 61.77      A    C
> ATOM    747  CB AASN A 116      28.182  38.336 -24.223  0.50 69.02      A    C
> ATOM    748  CG AASN A 116      29.037  39.555 -24.495  0.50 79.45      A    C
> ATOM    749  OD1AASN A 116      28.656  40.644 -24.047  0.50 83.18      A    O
> ATOM    750  ND2AASN A 116      30.178  39.419 -25.218  0.50 87.72      A    N
> ATOM    751  C   ASN A 116      29.353  36.143 -24.389  1.00 53.28      A    C
> ATOM    752  O   ASN A 116      29.778  36.380 -23.266  1.00 48.83      A    O
> ATOM    753  CA BASN A 116      28.575  37.144 -25.135  0.50 61.77      A    C
> ATOM    754  CB BASN A 116      28.282  38.336 -24.223  0.50 69.02      A    C
> ATOM    755  CG BASN A 116      29.487  39.201 -23.920  0.50 79.45      A    C
> ATOM    756  OD1BASN A 116      30.611  38.710 -24.084  0.50 83.18      A    O
> ATOM    757  ND2BASN A 116      29.299  40.471 -23.478  0.50 87.72      A    N
> 
> The Refmac log output shows that link description was recognized correctly 
> for each conformation:
>   WARNING : residue: NAG                 1  chain:EE
>             atom: "O1  " is absent in coord_file
>   WARNING : link(spec):NAG-ASN  is found dist =     1.466 ideal_dist=     
> 1.439
>             ch:EE   res:   1  NAG              at:C1  A->AA   res: 116  ASN   
>            at:ND2 A
>   WARNING : link(spec):NAG-ASN  is found dist =     1.244 ideal_dist=     
> 1.439
>             ch:EE   res:   1  NAG              at:C1  B->AA   res: 116  ASN   
>            at:ND2 B
> 
> 
> Best regards,
> Markus
> 
> -- 
> Markus Meier, Ph.D.
> University of Manitoba
> Department of Chemistry
> 144 Dysart Road

-- 
Markus Meier, Ph.D.
University of Manitoba
Department of Chemistry
144 Dysart Road
Winnipeg, MB, R3T 2N2, Canada
Phone:  +1 204 474 7172
Fax:    +1 204 474 7608
E-mail: [email protected]

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