WHAT IF Check report

This file was created 2011-12-17 from WHAT_CHECK output by a conversion script. If you are new to WHAT_CHECK, please study the pdbreport pages. There also exists a legend to the output.

Please note that you are looking at an abridged version of the output (all checks that gave normal results have been removed from this report). You can have a look at the Full report instead.

Verification log for pdb3pdo.ent

Checks that need to be done early-on in validation

Warning: Class of conventional cell differs from CRYST1 cell

The crystal class of the conventional cell is different from the crystal class of the cell given on the CRYST1 card. If the new class is supported by the coordinates this is an indication of a wrong space group assignment.

The CRYST1 cell dimensions

    A    =  45.450  B   =  97.627  C    =  99.052
    Alpha=  90.000  Beta=  90.000  Gamma=  90.000

Dimensions of a reduced cell

    A    =  45.450  B   =  97.627  C    =  99.052
    Alpha=  90.000  Beta=  90.000  Gamma=  90.000

Dimensions of the conventional cell

    A    =  99.052  B   =  97.627  C    =  45.450
    Alpha=  90.000  Beta=  90.000  Gamma=  90.000

Transformation to conventional cell

 |  0.000000  0.000000 -1.000000|
 |  0.000000  1.000000  0.000000|
 |  1.000000  0.000000  0.000000|

Crystal class of the cell: ORTHORHOMBIC

Crystal class of the conventional CELL: TETRAGONAL

Space group name: P 21 21 21

Bravais type of conventional cell is: P

Warning: Conventional cell is pseudo-cell

The extra symmetry that would be implied by the transition to the previously mentioned conventional cell has not been observed. It must be concluded that the crystal lattice has pseudo-symmetry.

Warning: Ligands for which a topology was generated automatically

The topology for the ligands in the table below were determined automatically. WHAT IF uses a local copy of Daan van Aalten's Dundee PRODRG server to automatically generate topology information for ligands. For this PDB file that seems to have gone fine, but be aware that automatic topology generation is a complicated task. So, if you get messages that you fail to understand or that you believe are wrong, and one of these ligands is involved, then check the ligand topology first.

 394 GOL   ( 193-)  A  -
 395 GOL   ( 199-)  B  -
 396 FMT   ( 200-)  B  -

Non-validating, descriptive output paragraph

Note: Ramachandran plot

In this Ramachandran plot x-signs represent glycines, squares represent prolines, and plus-signs represent the other residues. If too many plus- signs fall outside the contoured areas then the molecule is poorly refined (or worse). Proline can only occur in the narrow region around phi=-60 that also falls within the other contour islands.

In a colour picture, the residues that are part of a helix are shown in blue, strand residues in red. Preferred regions for helical residues are drawn in blue, for strand residues in red, and for all other residues in green. A full explanation of the Ramachandran plot together with a series of examples can be found at the WHAT_CHECK website.

Chain identifier: A

Note: Ramachandran plot

Chain identifier: B

Note: Ramachandran plot

Chain identifier: C

Coordinate problems, unexpected atoms, B-factor and occupancy checks

Warning: Missing atoms

The atoms listed in the table below are missing from the entry. If many atoms are missing, the other checks can become less sensitive. Be aware that it often happens that groups at the termini of DNA or RNA are really missing, so that the absence of these atoms normally is neither an error nor the result of poor electron density. Some of the atoms listed here might also be listed by other checks, most noticeably by the options in the previous section that list missing atoms in several categories. The plausible atoms with zero occupancy are not listed here, as they already got assigned a non-zero occupancy, and thus are no longer 'missing'.

  47 GLU   (  46-)  A      CG
  47 GLU   (  46-)  A      CD
  47 GLU   (  46-)  A      OE1
  47 GLU   (  46-)  A      OE2
 251 LYS   (  65-)  B      CG
 251 LYS   (  65-)  B      CD
 251 LYS   (  65-)  B      CE
 251 LYS   (  65-)  B      NZ

Warning: What type of B-factor?

WHAT IF does not yet know well how to cope with B-factors in case TLS has been used. It simply assumes that the B-factor listed on the ATOM and HETATM cards are the total B-factors. When TLS refinement is used that assumption sometimes is not correct. The header of the PDB file states that TLS groups were used. So, if WHAT IF complains about your B-factors, while you think that they are OK, then check for TLS related B-factor problems first.

Obviously, the temperature at which the X-ray data was collected has some importance too:


Number of TLS groups mentione in PDB file header: 0

Crystal temperature (K) :100.000

Note: B-factor plot

The average atomic B-factor per residue is plotted as function of the residue number.

Chain identifier: A

Note: B-factor plot

Chain identifier: B

Note: B-factor plot

Chain identifier: C

Nomenclature related problems

Warning: Arginine nomenclature problem

The arginine residues listed in the table below have their N-H-1 and N-H-2 swapped.

 209 ARG   (  23-)  B

Warning: Tyrosine convention problem

The tyrosine residues listed in the table below have their chi-2 not between -90.0 and 90.0

 162 TYR   ( 161-)  A
 233 TYR   (  47-)  B
 288 TYR   ( 102-)  B
 309 TYR   ( 123-)  B
 357 TYR   ( 171-)  B

Warning: Phenylalanine convention problem

The phenylalanine residues listed in the table below have their chi-2 not between -90.0 and 90.0.

  52 PHE   (  51-)  A
 138 PHE   ( 137-)  A
 146 PHE   ( 145-)  A
 181 PHE   ( 180-)  A
 193 PHE   (   7-)  B
 199 PHE   (  13-)  B
 203 PHE   (  17-)  B
 308 PHE   ( 122-)  B
 341 PHE   ( 155-)  B

Warning: Aspartic acid convention problem

The aspartic acid residues listed in the table below have their chi-2 not between -90.0 and 90.0, or their proton on OD1 instead of OD2.

 160 ASP   ( 159-)  A

Warning: Glutamic acid convention problem

The glutamic acid residues listed in the table below have their chi-3 outside the -90.0 to 90.0 range, or their proton on OE1 instead of OE2.

   5 GLU   (   4-)  A
  48 GLU   (  47-)  A
  99 GLU   (  98-)  A
 135 GLU   ( 134-)  A
 180 GLU   ( 179-)  A
 282 GLU   (  96-)  B

Geometric checks

Warning: Possible cell scaling problem

Comparison of bond distances with Engh and Huber [REF] standard values for protein residues and Parkinson et al [REF] values for DNA/RNA shows a significant systematic deviation. It could be that the unit cell used in refinement was not accurate enough. The deformation matrix given below gives the deviations found: the three numbers on the diagonal represent the relative corrections needed along the A, B and C cell axis. These values are 1.000 in a normal case, but have significant deviations here (significant at the 99.99 percent confidence level)

There are a number of different possible causes for the discrepancy. First the cell used in refinement can be different from the best cell calculated. Second, the value of the wavelength used for a synchrotron data set can be miscalibrated. Finally, the discrepancy can be caused by a dataset that has not been corrected for significant anisotropic thermal motion.

Please note that the proposed scale matrix has NOT been restrained to obey the space group symmetry. This is done on purpose. The distortions can give you an indication of the accuracy of the determination.

If you intend to use the result of this check to change the cell dimension of your crystal, please read the extensive literature on this topic first. This check depends on the wavelength, the cell dimensions, and on the standard bond lengths and bond angles used by your refinement software.

Unit Cell deformation matrix

 |  1.001636 -0.001614 -0.000104|
 | -0.001614  0.994651  0.000887|
 | -0.000104  0.000887  0.995679|
Proposed new scale matrix

 |  0.021966  0.000036  0.000002|
 |  0.000017  0.010298 -0.000009|
 |  0.000001 -0.000009  0.010140|
With corresponding cell

    A    =  45.525  B   =  97.106  C    =  98.621
    Alpha=  89.898  Beta=  90.012  Gamma=  90.185

The CRYST1 cell dimensions

    A    =  45.450  B   =  97.627  C    =  99.052
    Alpha=  90.000  Beta=  90.000  Gamma=  90.000

Variance: 163.063
(Under-)estimated Z-score: 9.411

Error: Nomenclature error(s)

Checking for a hand-check. WHAT IF has over the course of this session already corrected the handedness of atoms in several residues. These were administrative corrections. These residues are listed here.

   5 GLU   (   4-)  A
  48 GLU   (  47-)  A
  99 GLU   (  98-)  A
 135 GLU   ( 134-)  A
 160 ASP   ( 159-)  A
 180 GLU   ( 179-)  A
 209 ARG   (  23-)  B
 282 GLU   (  96-)  B

Torsion-related checks

Warning: Torsion angle evaluation shows unusual residues

The residues listed in the table below contain bad or abnormal torsion angles.

These scores give an impression of how `normal' the torsion angles in protein residues are. All torsion angles except omega are used for calculating a `normality' score. Average values and standard deviations were obtained from the residues in the WHAT IF database. These are used to calculate Z-scores. A residue with a Z-score of below -2.0 is poor, and a score of less than -3.0 is worrying. For such residues more than one torsion angle is in a highly unlikely position.

 313 ILE   ( 127-)  B    -2.6
 114 THR   ( 113-)  A    -2.5
 349 THR   ( 163-)  B    -2.4
  93 LEU   (  92-)  A    -2.2
 343 THR   ( 157-)  B    -2.2
 224 VAL   (  38-)  B    -2.1
 154 PHE   ( 153-)  A    -2.1
 220 GLN   (  34-)  B    -2.1
 197 LEU   (  11-)  B    -2.1
 118 VAL   ( 117-)  A    -2.1
 176 LEU   ( 175-)  A    -2.1
 373 GLU   ( 187-)  B    -2.0

Warning: Backbone evaluation reveals unusual conformations

The residues listed in the table below have abnormal backbone torsion angles.

Residues with `forbidden' phi-psi combinations are listed, as well as residues with unusual omega angles (deviating by more than 3 sigma from the normal value). Please note that it is normal if about 5 percent of the residues is listed here as having unusual phi-psi combinations.

  16 ASN   (  15-)  A  PRO omega poor
  40 LYS   (  39-)  A  Poor phi/psi
  88 PRO   (  87-)  A  omega poor
 101 ARG   ( 100-)  A  Poor phi/psi
 110 ILE   ( 109-)  A  omega poor
 112 LYS   ( 111-)  A  Poor phi/psi
 114 THR   ( 113-)  A  PRO omega poor
 130 THR   ( 129-)  A  Poor phi/psi
 144 HIS   ( 143-)  A  Poor phi/psi
 182 ASP   ( 181-)  A  Poor phi/psi
 188 ASP   (   2-)  B  Poor phi/psi
 219 ASN   (  33-)  B  Poor phi/psi
 220 GLN   (  34-)  B  Poor phi/psi
 272 GLY   (  86-)  B  omega poor
 276 THR   (  90-)  B  Poor phi/psi
 295 LEU   ( 109-)  B  Poor phi/psi
 300 LEU   ( 114-)  B  omega poor
 309 TYR   ( 123-)  B  PRO omega poor
 331 THR   ( 145-)  B  omega poor
 332 GLY   ( 146-)  B  omega poor
 339 TRP   ( 153-)  B  Poor phi/psi
 341 PHE   ( 155-)  B  omega poor
 354 GLY   ( 168-)  B  Poor phi/psi
 chi-1/chi-2 correlation Z-score : -1.707

Warning: Unusual backbone conformations

For the residues listed in the table below, the backbone formed by itself and two neighbouring residues on either side is in a conformation that is not seen very often in the database of solved protein structures. The number given in the table is the number of similar backbone conformations in the database with the same amino acid in the centre.

For this check, backbone conformations are compared with database structures using C-alpha superpositions with some restraints on the backbone oxygen positions.

A residue mentioned in the table can be part of a strange loop, or there might be something wrong with it or its directly surrounding residues. There are a few of these in every protein, but in any case it is worth looking at!

   4 GLU   (   3-)  A      0
  12 GLU   (  11-)  A      0
  16 ASN   (  15-)  A      0
  27 PHE   (  26-)  A      0
  33 PHE   (  32-)  A      0
  45 ARG   (  44-)  A      0
  52 PHE   (  51-)  A      0
  80 TYR   (  79-)  A      0
 100 LEU   (  99-)  A      0
 101 ARG   ( 100-)  A      0
 111 ASP   ( 110-)  A      0
 112 LYS   ( 111-)  A      0
 113 PHE   ( 112-)  A      0
 114 THR   ( 113-)  A      0
 116 PRO   ( 115-)  A      0
 117 VAL   ( 116-)  A      0
 124 ARG   ( 123-)  A      0
 130 THR   ( 129-)  A      0
 131 THR   ( 130-)  A      0
 134 SER   ( 133-)  A      0
 138 PHE   ( 137-)  A      0
 144 HIS   ( 143-)  A      0
 168 HIS   ( 167-)  A      0
 171 LEU   ( 170-)  A      0
 179 TRP   ( 178-)  A      0
And so on for a total of 143 lines.

Warning: Unusual PRO puckering amplitudes

The proline residues listed in the table below have a puckering amplitude that is outside of normal ranges. Puckering parameters were calculated by the method of Cremer and Pople [REF]. Normal PRO rings have a puckering amplitude Q between 0.20 and 0.45 Angstrom. If Q is lower than 0.20 Angstrom for a PRO residue, this could indicate disorder between the two different normal ring forms (with C-gamma below and above the ring, respectively). If Q is higher than 0.45 Angstrom something could have gone wrong during the refinement. Be aware that this is a warning with a low confidence level. See: Who checks the checkers? Four validation tools applied to eight atomic resolution structures [REF]

 242 PRO   (  56-)  B    0.17 LOW
 283 PRO   (  97-)  B    0.17 LOW

Warning: Unusual PRO puckering phases

The proline residues listed in the table below have a puckering phase that is not expected to occur in protein structures. Puckering parameters were calculated by the method of Cremer and Pople [REF]. Normal PRO rings approximately show a so-called envelope conformation with the C-gamma atom above the plane of the ring (phi=+72 degrees), or a half-chair conformation with C-gamma below and C-beta above the plane of the ring (phi=-90 degrees). If phi deviates strongly from these values, this is indicative of a very strange conformation for a PRO residue, and definitely requires a manual check of the data. Be aware that this is a warning with a low confidence level. See: Who checks the checkers? Four validation tools applied to eight atomic resolution structures [REF].

  82 PRO   (  81-)  A   -43.5 envelop C-alpha (-36 degrees)
 174 PRO   ( 173-)  A   101.8 envelop C-beta (108 degrees)
 369 PRO   ( 183-)  B  -127.3 half-chair C-delta/C-gamma (-126 degrees)
 377 PRO   ( 103-)  C     0.2 envelop N (0 degrees)
 386 PRO   ( 112-)  C    51.9 half-chair C-delta/C-gamma (54 degrees)

Bump checks

Error: Abnormally short interatomic distances

The pairs of atoms listed in the table below have an unusually short interactomic distance; each bump is listed in only one direction.

The contact distances of all atom pairs have been checked. Two atoms are said to `bump' if they are closer than the sum of their Van der Waals radii minus 0.40 Angstrom. For hydrogen bonded pairs a tolerance of 0.55 Angstrom is used. The first number in the table tells you how much shorter that specific contact is than the acceptable limit. The second distance is the distance between the centres of the two atoms. Although we believe that two water atoms at 2.4 A distance are too close, we only report water pairs that are closer than this rather short distance.

The last text-item on each line represents the status of the atom pair. If the final column contains the text 'HB', the bump criterion was relaxed because there could be a hydrogen bond. Similarly relaxed criteria are used for 1-3 and 1-4 interactions (listed as 'B2' and 'B3', respectively). BL indicates that the B-factors of the clashing atoms have a low B-factor thereby making this clash even more worrisome. INTRA and INTER indicate whether the clashes are between atoms in the same asymmetric unit, or atoms in symmetry related asymmetric units, respectively.

 319 ARG   ( 133-)  B      NH1 <->  355 GLU   ( 169-)  B      OE2    0.37    2.33  INTRA BF
 391 ALA   ( 117-)  C      N   <->  399 HOH   ( 181 )  C      O      0.36    2.34  INTRA BF
 246 TYR   (  60-)  B      CZ  <->  250 GLN   (  64-)  B      NE2    0.36    2.74  INTRA BF
 112 LYS   ( 111-)  A      NZ  <->  397 HOH   ( 304 )  A      O      0.34    2.36  INTRA
 148 LYS   ( 147-)  A      NZ  <->  150 HIS   ( 149-)  A      CE1    0.28    2.82  INTRA BL
 160 ASP   ( 159-)  A      O   <->  397 HOH   ( 262 )  A      O      0.26    2.14  INTRA BF
 229 ASP   (  43-)  B      OD2 <->  398 HOH   ( 217 )  B      O      0.24    2.16  INTRA
  76 LYS   (  75-)  A      O   <->   79 ASN   (  78-)  A      N      0.23    2.47  INTRA
 177 LYS   ( 176-)  A      NZ  <->  397 HOH   ( 197 )  A      O      0.23    2.47  INTRA BF
 144 HIS   ( 143-)  A      ND1 <->  198 LYS   (  12-)  B      NZ     0.22    2.78  INTRA BL
 241 ARG   (  55-)  B      N   <->  242 PRO   (  56-)  B      CD     0.18    2.82  INTRA BL
 282 GLU   (  96-)  B      N   <->  398 HOH   ( 241 )  B      O      0.18    2.52  INTRA BL
 297 HIS   ( 111-)  B      CG  <->  298 HIS   ( 112-)  B      N      0.18    2.82  INTRA BF
 250 GLN   (  64-)  B      OE1 <->  398 HOH   ( 266 )  B      O      0.17    2.23  INTRA BF
 177 LYS   ( 176-)  A      CD  <->  397 HOH   ( 197 )  A      O      0.16    2.64  INTRA BF
 319 ARG   ( 133-)  B      NE  <->  398 HOH   ( 242 )  B      O      0.14    2.56  INTRA BF
 324 GLU   ( 138-)  B      OE1 <->  398 HOH   ( 260 )  B      O      0.13    2.27  INTRA BF
  14 TYR   (  13-)  A      OH  <->  397 HOH   ( 329 )  A      O      0.13    2.27  INTRA
 139 LEU   ( 138-)  A      N   <->  147 ARG   ( 146-)  A      O      0.12    2.58  INTRA BL
 316 ARG   ( 130-)  B      NH2 <->  323 GLU   ( 137-)  B      OE1    0.12    2.58  INTRA
  59 GLY   (  58-)  A      C   <->  383 MET   ( 109-)  C      SD     0.10    3.30  INTRA
  96 SER   (  95-)  A      CB  <->   97 PRO   (  96-)  A      CD     0.10    3.00  INTRA
 234 ARG   (  48-)  B      NH2 <->  398 HOH   ( 276 )  B      O      0.10    2.60  INTRA
 363 HIS   ( 177-)  B      ND1 <->  365 SER   ( 179-)  B      OG     0.09    2.61  INTRA BL
  47 GLU   (  46-)  A      O   <->  397 HOH   ( 268 )  A      O      0.09    2.31  INTRA
And so on for a total of 63 lines.

Packing, accessibility and threading

Note: Inside/Outside RMS Z-score plot

The Inside/Outside distribution normality RMS Z-score over a 15 residue window is plotted as function of the residue number. High areas in the plot (above 1.5) indicate unusual inside/outside patterns.

Chain identifier: A

Note: Inside/Outside RMS Z-score plot

Chain identifier: B

Note: Inside/Outside RMS Z-score plot

Chain identifier: C

Warning: Abnormal packing environment for some residues

The residues listed in the table below have an unusual packing environment.

The packing environment of the residues is compared with the average packing environment for all residues of the same type in good PDB files. A low packing score can indicate one of several things: Poor packing, misthreading of the sequence through the density, crystal contacts, contacts with a co-factor, or the residue is part of the active site. It is not uncommon to see a few of these, but in any case this requires further inspection of the residue.

 101 ARG   ( 100-)  A      -6.45
 352 ARG   ( 166-)  B      -6.07
 375 ARG   ( 189-)  B      -5.97
 392 LEU   ( 118-)  C      -5.92
 295 LEU   ( 109-)  B      -5.63
 325 LYS   ( 139-)  B      -5.55
  19 GLN   (  18-)  A      -5.07
 297 HIS   ( 111-)  B      -5.06

Warning: Abnormal packing environment for sequential residues

A stretch of at least three sequential residues with a questionable packing environment was found. This could indicate that these residues are part of a strange loop. It might also be an indication of misthreading in the density. However, it can also indicate that one or more residues in this stretch have other problems such as, for example, missing atoms, very weird angles or bond lengths, etc.

The table below lists the first and last residue in each stretch found, as well as the average residue score of the series.

 295 LEU   ( 109-)  B       298 - HIS    112- ( B)         -4.76

Note: Quality value plot

The quality value smoothed over a 10 residue window is plotted as function of the residue number. Low areas in the plot (below -2.0) indicate unusual packing.

Chain identifier: A

Note: Quality value plot

The quality value smoothed over a 10 residue window is plotted as function of the residue number. Low areas in the plot (below -2.0) indicate unusual packing.

Chain identifier: B

Note: Quality value plot

The quality value smoothed over a 10 residue window is plotted as function of the residue number. Low areas in the plot (below -2.0) indicate unusual packing.

Chain identifier: C

Note: Second generation quality Z-score plot

The second generation quality Z-score smoothed over a 10 residue window is plotted as function of the residue number. Low areas in the plot (below -1.3) indicate unusual packing.

Chain identifier: A

Note: Second generation quality Z-score plot

Chain identifier: B

Note: Second generation quality Z-score plot

Chain identifier: C

Water, ion, and hydrogenbond related checks

Error: Water molecules without hydrogen bonds

The water molecules listed in the table below do not form any hydrogen bonds, neither with the protein or DNA/RNA, nor with other water molecules. This is a strong indication of a refinement problem. The last number on each line is the identifier of the water molecule in the input file.

 397 HOH   ( 248 )  A      O
 397 HOH   ( 298 )  A      O
 398 HOH   ( 203 )  B      O
 398 HOH   ( 255 )  B      O

Error: HIS, ASN, GLN side chain flips

Listed here are Histidine, Asparagine or Glutamine residues for which the orientation determined from hydrogen bonding analysis are different from the assignment given in the input. Either they could form energetically more favourable hydrogen bonds if the terminal group was rotated by 180 degrees, or there is no assignment in the input file (atom type 'A') but an assignment could be made. Be aware, though, that if the topology could not be determined for one or more ligands, then this option will make errors.

  58 GLN   (  57-)  A
 150 HIS   ( 149-)  A
 342 GLN   ( 156-)  B

Warning: Buried unsatisfied hydrogen bond donors

The buried hydrogen bond donors listed in the table below have a hydrogen atom that is not involved in a hydrogen bond in the optimized hydrogen bond network.

Hydrogen bond donors that are buried inside the protein normally use all of their hydrogens to form hydrogen bonds within the protein. If there are any non hydrogen bonded buried hydrogen bond donors in the structure they will be listed here. In very good structures the number of listed atoms will tend to zero.

Waters are not listed by this option.

  46 LEU   (  45-)  A      N
 211 ARG   (  25-)  B      NH2
 215 ARG   (  29-)  B      NE
 232 GLU   (  46-)  B      N
 235 ALA   (  49-)  B      N
 293 GLN   ( 107-)  B      N
 298 HIS   ( 112-)  B      N
 392 LEU   ( 118-)  C      N

Warning: Buried unsatisfied hydrogen bond acceptors

The buried side-chain hydrogen bond acceptors listed in the table below are not involved in a hydrogen bond in the optimized hydrogen bond network.

Side-chain hydrogen bond acceptors buried inside the protein normally form hydrogen bonds within the protein. If there are any not hydrogen bonded in the optimized hydrogen bond network they will be listed here.

Waters are not listed by this option.

  12 GLU   (  11-)  A      OE1
  67 ASP   (  66-)  A      OD2
 178 HIS   ( 177-)  A      NE2
 252 ASP   (  66-)  B      OD2

Warning: Unusual water packing

We implemented the ion valence determination method of Brown and Wu [REF] similar to Nayal and Di Cera [REF] and Mueller, Koepke and Sheldrick [REF]. It must be stated that the validation of ions in PDB files is very difficult. Ideal ion-ligand distances often differ no more than 0.1 Angstrom, and in a 2.0 Angstrom resolution structure 0.1 Angstrom is not very much. Nayal and Di Cera showed that this method nevertheless has great potential for detecting water molecules that actually should be metal ions. The method has not been extensively validated, though. Part of our implementation (comparing waters with multiple ion types) is even fully new and despite that we see it work well in the few cases that are trivial, we must emphasize that this method is untested.

The score listed is the valency score. This number should be close to (preferably a bit above) 1.0 for the suggested ion to be a likely alternative for the water molecule. Ions listed in brackets are good alternate choices. *1 indicates that the suggested ion-type has been observed elsewhere in the PDB file too. *2 indicates that the suggested ion-type has been observed in the REMARK 280 cards of the PDB file. Ion-B and ION-B indicate that the B-factor of this water is high, or very high, respectively. H2O-B indicates that the B-factors of atoms that surround this water/ion are suspicious. See: swift.cmbi.ru.nl/teach/theory/ for a detailed explanation.

 397 HOH   ( 199 )  A      O  0.87  K  5

Warning: Possible wrong residue type

The residues listed in the table below have a weird environment that cannot be improved by rotamer flips. This can mean one of three things, non of which WHAT CHECK really can do much about. 1) The side chain has actually another rotamer than is present in the PDB file; 2) A counter ion is present in the structure but is not given in the PDB file; 3) The residue actually is another amino acid type. The annotation 'Alt-rotamer' indicates that WHAT CHECK thinks you might want to find an alternate rotamer for this residue. The annotation 'Sym-induced' indicates that WHAT CHECK believes that symmetry contacts might have something to do with the difficulties of this residue's side chain. Determination of these two annotations is difficult, so their absence is less meaningful than their presence. The annotation Ligand-bound indicates that a ligand seems involved with this residue. In nine of ten of these cases this indicates that the ligand is causing the weird situation rather than the residue.

  22 GLU   (  21-)  A   H-bonding suggests Gln
  67 ASP   (  66-)  A   H-bonding suggests Asn
 163 ASP   ( 162-)  A   H-bonding suggests Asn; but Alt-Rotamer
 338 ASP   ( 152-)  B   H-bonding suggests Asn; Ligand-contact
 348 GLU   ( 162-)  B   H-bonding suggests Gln; but Alt-Rotamer

Final summary

Note: Summary report for users of a structure

This is an overall summary of the quality of the structure as compared with current reliable structures. This summary is most useful for biologists seeking a good structure to use for modelling calculations.

The second part of the table mostly gives an impression of how well the model conforms to common refinement restraint values. The first part of the table shows a number of global quality indicators.


Structure Z-scores, positive is better than average:

  1st generation packing quality :   0.306
  2nd generation packing quality :  -0.963
  Ramachandran plot appearance   :  -0.047
  chi-1/chi-2 rotamer normality  :  -1.707
  Backbone conformation          :   0.017

RMS Z-scores, should be close to 1.0:
  Bond lengths                   :   0.713
  Bond angles                    :   0.769
  Omega angle restraints         :   1.169
  Side chain planarity           :   0.764
  Improper dihedral distribution :   0.880
  B-factor distribution          :   0.673
  Inside/Outside distribution    :   1.046

Note: Summary report for depositors of a structure

This is an overall summary of the quality of the X-ray structure as compared with structures solved at similar resolutions. This summary can be useful for a crystallographer to see if the structure makes the best possible use of the data. Warning. This table works well for structures solved in the resolution range of the structures in the WHAT IF database, which is presently (summer 2008) mainly 1.1 - 1.3 Angstrom. The further the resolution of your file deviates from this range the more meaningless this table becomes.

The second part of the table mostly gives an impression of how well the model conforms to common refinement restraint values. The first part of the table shows a number of global quality indicators, which have been calibrated against structures of similar resolution.

Resolution found in PDB file : 1.95


Structure Z-scores, positive is better than average:

  1st generation packing quality :   0.7
  2nd generation packing quality :  -1.1
  Ramachandran plot appearance   :   0.0
  chi-1/chi-2 rotamer normality  :  -1.0
  Backbone conformation          :  -0.7

RMS Z-scores, should be close to 1.0:
  Bond lengths                   :   0.713
  Bond angles                    :   0.769
  Omega angle restraints         :   1.169
  Side chain planarity           :   0.764
  Improper dihedral distribution :   0.880
  B-factor distribution          :   0.673
  Inside/Outside distribution    :   1.046
==============

WHAT IF
    G.Vriend,
      WHAT IF: a molecular modelling and drug design program,
    J. Mol. Graph. 8, 52--56 (1990).

WHAT_CHECK (verification routines from WHAT IF)
    R.W.W.Hooft, G.Vriend, C.Sander and E.E.Abola,
      Errors in protein structures
    Nature 381, 272 (1996).
    (see also http://swift.cmbi.ru.nl/gv/whatcheck for a course and extra inform

Bond lengths and angles, protein residues
    R.Engh and R.Huber,
      Accurate bond and angle parameters for X-ray protein structure
      refinement,
    Acta Crystallogr. A47, 392--400 (1991).

Bond lengths and angles, DNA/RNA
    G.Parkinson, J.Voitechovsky, L.Clowney, A.T.Bruenger and H.Berman,
      New parameters for the refinement of nucleic acid-containing structures
    Acta Crystallogr. D52, 57--64 (1996).

DSSP
    W.Kabsch and C.Sander,
      Dictionary of protein secondary structure: pattern
      recognition of hydrogen bond and geometrical features
    Biopolymers 22, 2577--2637 (1983).

Hydrogen bond networks
    R.W.W.Hooft, C.Sander and G.Vriend,
      Positioning hydrogen atoms by optimizing hydrogen bond networks in
      protein structures
    PROTEINS, 26, 363--376 (1996).

Matthews' Coefficient
    B.W.Matthews
      Solvent content of Protein Crystals
    J. Mol. Biol. 33, 491--497 (1968).

Protein side chain planarity
    R.W.W. Hooft, C. Sander and G. Vriend,
      Verification of protein structures: side-chain planarity
    J. Appl. Cryst. 29, 714--716 (1996).

Puckering parameters
    D.Cremer and J.A.Pople,
      A general definition of ring puckering coordinates
    J. Am. Chem. Soc. 97, 1354--1358 (1975).

Quality Control
    G.Vriend and C.Sander,
      Quality control of protein models: directional atomic
      contact analysis,
    J. Appl. Cryst. 26, 47--60 (1993).

Ramachandran plot
    G.N.Ramachandran, C.Ramakrishnan and V.Sasisekharan,
      Stereochemistry of Polypeptide Chain Conformations
    J. Mol. Biol. 7, 95--99 (1963).

Symmetry Checks
    R.W.W.Hooft, C.Sander and G.Vriend,
      Reconstruction of symmetry related molecules from protein
      data bank (PDB) files
    J. Appl. Cryst. 27, 1006--1009 (1994).

Ion Checks
    I.D.Brown and K.K.Wu,
      Empirical Parameters for Calculating Cation-Oxygen Bond Valences
    Acta Cryst. B32, 1957--1959 (1975).

    M.Nayal and E.Di Cera,
      Valence Screening of Water in Protein Crystals Reveals Potential Na+
      Binding Sites
    J.Mol.Biol. 256 228--234 (1996).

    P.Mueller, S.Koepke and G.M.Sheldrick,
      Is the bond-valence method able to identify metal atoms in protein
      structures?
    Acta Cryst. D 59 32--37 (2003).

Checking checks
    K.Wilson, C.Sander, R.W.W.Hooft, G.Vriend, et al.
      Who checks the checkers
    J.Mol.Biol. (1998) 276,417-436.