[phenixbb] Trouble with occupancy refinement

Christian Roth christianroth034 at gmail.com
Sun Feb 7 14:44:26 PST 2016


Dear Chris,

personally I wouldn't go for different occupancies in one ligand and set
everything to 1 or everything to a values of your choice (constraint groups
necessary). I would also check the electron density and the RSRZ for your
ligands. The B-factors look quite high. Concerning the outliers, that is
due to slight variations in the boundaries. Your outliers are probably
exactly on a boundary. I wouldn't worry too much about that. They are fine.

Cheers

Christian


On Sat, Feb 6, 2016 at 12:19 PM, Chris Fage <cdfage at gmail.com> wrote:

> Hello,
>
> The non-unity occupancies were scattered among different glucose (and
> BICINE) molecules, as shown below. But, again, I think the occupancy
> refinement doesn't contribute much to the final model/maps.
>
> Another concern of mind is that phenix.refine reports no Ramachandran
> outliers in the results, but the plot in Coot lists 5. I'm tempted to trust
> Coot here and attempt to fix these boundary cases.
>
> Best,
> Chris
>
> HETATM10716  N1  BCN S   1      33.836  34.201  59.534  0.18
> 23.53           N
>
> HETATM10717  C1  BCN S   1      34.230  32.958  58.836
> 0.70179.13           C
>
> HETATM10718  C2  BCN S   1      34.891  33.313  57.492
> 1.00115.73           C
>
> HETATM10719  O21 BCN S   1      34.957  34.518  57.119
> 1.00109.54           O
>
> HETATM10720  O22 BCN S   1      35.367  32.401  56.762
> 1.00108.31           O
>
> HETATM10721  C3  BCN S   1      34.436  34.251  60.889
> 1.00133.37           C
>
> HETATM10722  C4  BCN S   1      35.959  33.990  60.820
>  1.00145.21           C
>
> HETATM10723  O4  BCN S   1      36.512  34.130  62.106
> 1.00128.90           O
>
> HETATM10724  C5  BCN S   1      32.359  34.284  59.630
> 1.00138.45           C
>
> HETATM10725  C6  BCN S   1      31.834  33.285  60.690  1.00149.79
>       C
>
> HETATM10726  O6  BCN S   1      31.344  32.131  60.054
> 1.00182.66           O
>
> TER
>
> HETATM10727  C1  GLC T   1      29.246  35.417  65.683
> 1.00146.58           C
>
> HETATM10728  O1  GLC T   1      28.834  34.126  66.073
> 0.96127.55           O
>
> HETATM10729  O5  GLC T   1      28.195  36.040  64.979
> 1.00124.69           O
>
> HETATM10730  C5  GLC T   1      28.505  37.368  64.624
> 1.00122.20           C
>
> HETATM10731  C6  GLC T   1      27.259  38.050  64.075
> 1.00119.08           C
>
> HETATM10732  O6  GLC T   1      26.187  37.862  64.970
> 1.00119.13           O
>
> HETATM10733  C4  GLC T   1      29.637  37.367  63.604
> 1.00136.04           C
>
> HETATM10734  O4  GLC T   1      29.990  38.695  63.289
> 1.00149.55           O
>
> HETATM10735  C3  GLC T   1      30.857  36.629  64.144
> 1.00123.84           C
>
> HETATM10736  O3  GLC T   1      31.753  36.382  63.084
> 1.00155.37           O
>
> HETATM10737  C2  GLC T   1      30.484  35.302  64.800
> 1.00125.03           C
>
> HETATM10738  O2  GLC T   1      31.567  34.865  65.591
> 0.63132.05           O
>
> TER
>
> HETATM10739  C1  GLC U   1      66.828  61.786 109.714
> 1.00143.00           C
>
> HETATM10740  O1  GLC U   1      67.797  62.779 109.467
> 0.00156.33           O
>
> HETATM10741  O5  GLC U   1      67.461  60.579 110.071
> 1.00138.44           O
>
> HETATM10742  C5  GLC U   1      66.549  59.587 110.494
> 1.00130.87           C
>
> HETATM10743  C6  GLC U   1      67.332  58.348 110.912
> 1.00126.41           C
>
> HETATM10744  O6  GLC U   1      66.446  57.387 111.438
> 1.00130.55           O
>
> HETATM10745  C4  GLC U   1      65.554  59.239 109.389
> 1.00143.93           C
>
> HETATM10746  O4  GLC U   1      64.505  58.479 109.947  1.00
> 96.88           O
>
> HETATM10747  C3  GLC U   1      64.961  60.468 108.707
> 1.00123.83           C
>
> HETATM10748  O3  GLC U   1      64.402  60.081 107.473
> 0.00105.55           O
>
> HETATM10749  C2  GLC U   1      66.006  61.547 108.457
> 1.00183.06           C
>
> HETATM10750  O2  GLC U   1      65.369  62.743 108.070
> 1.00139.75           O
>
> TER
>
> HETATM10751  C1  GLC V   1      54.972  17.830  19.939
> 1.00169.39           C
>
> HETATM10752  O1  GLC V   1      53.783  17.971  20.683
> 1.00144.51           O
>
> HETATM10753  O5  GLC V   1      54.838  16.740  19.052
> 1.00159.54           O
>
> HETATM10754  C5  GLC V   1      55.968  16.571  18.224
> 1.00189.07           C
>
> HETATM10755  C6  GLC V   1      55.684  15.517  17.160
> 0.00157.50           C
>
> HETATM10756  O6  GLC V   1      56.642  15.622  16.130
> 0.00150.00           O
>
> HETATM10757  C4  GLC V   1      57.171  16.190  19.078
> 1.00197.13           C
>
> HETATM10758  O4  GLC V   1      58.312  16.053  18.263
> 0.00169.52           O
>
> HETATM10759  C3  GLC V   1      57.420  17.249  20.145
> 1.00158.70           C
>
> HETATM10760  O3  GLC V   1      58.385  16.779  21.059  1.00146.18
>      O
>
> HETATM10761  C2  GLC V   1      56.137  17.593  20.894
> 1.00148.03           C
>
> HETATM10762  O2  GLC V   1      56.348  18.756  21.663
> 0.00152.95           O
>
> TER
>
> HETATM10763  C1  GLC W   1      31.538  68.920 102.287
> 1.00113.76           C
>
> HETATM10764  O1  GLC W   1      32.846  68.776 101.784
> 1.00103.09           O
>
> HETATM10765  O5  GLC W   1      30.704  67.928 101.734
> 1.00117.86           O
>
> HETATM10766  C5  GLC W   1      29.403  67.910 102.284
> 1.00115.04           C
>
> HETATM10767  C6  GLC W   1      28.609  66.817 101.581
> 1.00106.54           C
>
> HETATM10768  O6  GLC W   1      28.601  67.074 100.194
> 0.00111.10           O
>
> HETATM10769  C4  GLC W   1      28.697  69.256 102.122
> 1.00117.67           C
>
> HETATM10770  O4  GLC W   1      27.558  69.277 102.955
> 1.00115.60           O
>
> HETATM10771  C3  GLC W   1      29.585  70.446 102.474
> 1.00115.77           C
>
> HETATM10772  O3  GLC W   1      29.006  71.627 101.968
> 1.00111.82           O
>
> HETATM10773  C2  GLC W   1      30.984  70.282 101.897
> 1.00114.72           C
>
> HETATM10774  O2  GLC W   1      31.827  71.303 102.379
> 0.00116.48           O
>
> TER
>
> HETATM10775  C1  GLC X   1      54.211  45.223  25.697
> 1.00206.04           C
>
> HETATM10776  O1  GLC X   1      55.322  45.961  25.241
> 1.00187.48           O
>
> HETATM10777  O5  GLC X   1      54.574  44.469  26.835
> 1.00228.70           O
>
> HETATM10778  C5  GLC X   1      53.489  43.765  27.404
> 1.00223.60           C
>
> HETATM10779  C6  GLC X   1      53.941  43.080  28.688
> 1.00159.71           C
>
> HETATM10780  O6  GLC X   1      54.911  42.103  28.384
> 1.00166.38           O
>
> HETATM10781  C4  GLC X   1      52.939  42.753  26.403
> 1.00163.35           C
>
> HETATM10782  O4  GLC X   1      51.806  42.113  26.943
> 0.00168.67           O
>
> HETATM10783  C3  GLC X   1      52.564  43.445  25.098
> 0.00164.83           C
>
> HETATM10784  O3  GLC X   1      52.207  42.489  24.126
> 0.00154.76           O
>
> HETATM10785  C2  GLC X   1      53.724  44.292  24.593
> 1.00198.64           C
>
> HETATM10786  O2  GLC X   1      53.308  45.050  23.479
> 1.00201.68           O
>
> TER
>
> HETATM10787  C1  GLC Y   1      36.970  50.317  37.435
> 1.00100.18           C
>
> HETATM10788  O1  GLC Y   1      37.809  50.485  36.323
> 1.00106.33           O
>
> HETATM10789  O5  GLC Y   1      35.664  50.350  36.918  1.00
> 98.74           O
>
> HETATM10790  C5  GLC Y   1      34.675  50.321  37.911  1.00
> 96.58           C
>
> HETATM10791  C6  GLC Y   1      33.320  50.170  37.238  1.00
> 94.30           C
>
> HETATM10792  O6  GLC Y   1      32.352  49.935  38.233  1.00
> 97.38           O
>
> HETATM10793  C4  GLC Y   1      34.760  51.605  38.726  1.00
> 94.56           C
>
> HETATM10794  O4  GLC Y   1      33.716  51.637  39.676  0.78
> 97.91           O
>
> HETATM10795  C3  GLC Y   1      36.127  51.715  39.398  1.00 96.51
>     C
>
> HETATM10796  O3  GLC Y   1      36.299  53.002  39.950  1.00
> 97.63           O
>
> HETATM10797  C2  GLC Y   1      37.230  51.499  38.366  1.00
> 98.97           C
>
> HETATM10798  O2  GLC Y   1      38.505  51.392  38.983
> 1.00101.52           O
>
> TER
>
> HETATM10799  C1  GLC Z   1      42.915  71.571  76.690
> 1.00101.13           C
>
> HETATM10800  O1  GLC Z   1      42.711  71.632  75.297
> 0.00103.04           O
>
> HETATM10801  O5  GLC Z   1      43.618  72.718  77.112
> 1.00100.13           O
>
> HETATM10802  C5  GLC Z   1      43.763  72.783  78.514
> 1.00103.11           C
>
> HETATM10803  C6  GLC Z   1      44.396  74.119  78.887
> 1.00100.33           C
>
> HETATM10804  O6  GLC Z   1      43.852  74.583  80.101
> 1.00102.36           O
>
> HETATM10805  C4  GLC Z   1      44.596  71.607  79.018
> 1.00101.96           C
>
> HETATM10806  O4  GLC Z   1      44.627  71.613  80.428  0.00
> 99.19           O
>
> HETATM10807  C3  GLC Z   1      44.030  70.278  78.527
> 1.00100.06           C
>
> HETATM10808  O3  GLC Z   1      44.956  69.245  78.783  1.00
> 95.83           O
>
> HETATM10809  C2  GLC Z   1      43.723  70.326  77.035  1.00
> 94.68           C
>
> HETATM10810  O2  GLC Z   1      42.998  69.176  76.663  1.00
> 91.83           O
>
> On Fri, Feb 5, 2016 at 7:34 PM, Christian Roth <christianroth034 at gmail.com
> > wrote:
>
>> Hi Chris, what would concern me is that one glucose have atoms with
>> different occupancies or all of them. That is chemically unlikely. You
>> should define sensible constraint groups, I think.
>>
>> Cheers Christian
>> On 5 Feb 2016 18:09, "Chris Fage" <cdfage at gmail.com> wrote:
>>
>>> Hi Pavel,
>>>
>>> The B-factors of these atoms are quite high (most are 100+), so maybe
>>> the occupancy is compensating as you said. After refinement, the maps don't
>>> look much different. Perhaps it's not worth bothering with occupancy
>>> refinement, then?
>>>
>>> I think you got my question. I was asking if it is unusual that only
>>> 5/93 occupancies were refined to values other than 0 or 1.
>>>
>>> Best,
>>> Chris
>>>
>>> On Fri, Feb 5, 2016 at 6:38 PM, Pavel Afonine <pafonine at lbl.gov> wrote:
>>>
>>>> Hi Chris,
>>>>
>>>> I've built several glucose molecules from my cryosolution into regions
>>>>> of weaker electron density. Attempting to refine the occupancies of the
>>>>> corresponding atoms, I set the value of each to 0.25 in the pdb file.
>>>>> However, after running phenix.refine, most of the atoms still have
>>>>> occupancies of 1.00:
>>>>>
>>>>
>>>> perhaps they are fully occupied but highly mobile which explains weak
>>>> density? Or B-factor refines to larger value so that occupancy tries to
>>>> compensate? How maps look like after refinement?
>>>>
>>>> 14 atoms with occ = 0.00
>>>>> 5 atoms with 0.00 < occ < 1.00
>>>>> 74 atoms with occ = 1.00
>>>>>
>>>>> Is this unusual?
>>>>>
>>>>
>>>> Do you mean is it unusual to have 5 atoms in your structure with
>>>> occupancies between 0 and 1? Hm.. I don't know, may be not! I think I'm not
>>>> understanding what's the real question here..
>>>>
>>>> Pavel
>>>>
>>>>
>>>
>>> _______________________________________________
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>>
>
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