WHAT IF Check report

This file was created 1997-08-24 from WHAT_CHECK output by a conversion script. If you are new to WHAT_CHECK, please read the introduction to the output.

Verification log for lebe.pdb

Symmetry related problems

Error: Missing unit cell information

No SCALE matrix is given in the PDB file.

Error: Missing symmetry information

Problem: No CRYST1 card is given in the PDB file.

Atom coordinate problems and/or unexpected atoms

Note: No rounded coordinates detected

No significant rounding of atom coordinates has been detected.

Nomenclature related problems

Note: Valine nomenclature OK

No errors were detected in valine nomenclature.

Note: Threonine nomenclature OK

No errors were detected in threonine nomenclature.

Note: Isoleucine nomenclature OK

No errors were detected in isoleucine nomenclature.

Note: Leucine nomenclature OK

No errors were detected in leucine nomenclature.

Warning: Arginine nomenclature problem

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

   8 ARG  (   8 )
  20 ARG  (  20 )
  36 ARG  (  36 )
  37 ARG  (  37 )
  51 ARG  (  51 )
  54 ARG  (  54 )
  64 ARG  (  64 )
  72 ARG  (  72 )
  97 ARG  (  97 )
 125 ARG  ( 125 )
 130 ARG  ( 130 )
 137 ARG  ( 137 )
 161 ARG  ( 161 )
 171 ARG  ( 171 )
 174 ARG  ( 174 )
 247 ARG  ( 247 )
 268 ARG  ( 268 )
 276 ARG  ( 276 )
 279 ARG  ( 279 )
 283 ARG  ( 283 )
 297 ARG  ( 297 )
 324 ARG  ( 324 )
 354 ARG  ( 354 )
 368 ARG  ( 368 )
 369 ARG  ( 369 )
 373 ARG  ( 373 )
 375 ARG  ( 375 )
 383 ARG  ( 383 )
 397 ARG  ( 397 )
 412 ARG  ( 412 )
 420 ARG  ( 420 )

Warning: Tyrosine convention problem

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

 190 TYR  ( 190 )
 194 TYR  ( 194 )
 197 TYR  ( 197 )
 323 TYR  ( 323 )
 341 TYR  ( 341 )
 406 TYR  ( 406 )

Warning: Phenylalanine convention problem

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

  23 PHE  (  23 )
 162 PHE  ( 162 )
 179 PHE  ( 179 )
 365 PHE  ( 365 )

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.

   3 ASP  (   3 )
  12 ASP  (  12 )
  26 ASP  (  26 )
  67 ASP  (  67 )
  83 ASP  (  83 )
  90 ASP  (  90 )
 109 ASP  ( 109 )
 116 ASP  ( 116 )
 133 ASP  ( 133 )
 150 ASP  ( 150 )
 182 ASP  ( 182 )
 202 ASP  ( 202 )
 216 ASP  ( 216 )
 255 ASP  ( 255 )
 288 ASP  ( 288 )
 300 ASP  ( 300 )
 332 ASP  ( 332 )
 364 ASP  ( 364 )

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.

  16 GLU  (  16 )
  50 GLU  (  50 )
  66 GLU  (  66 )
  74 GLU  (  74 )
  80 GLU  (  80 )
  81 GLU  (  81 )
  95 GLU  (  95 )
 117 GLU  ( 117 )
 122 GLU  ( 122 )
 186 GLU  ( 186 )
 192 GLU  ( 192 )
 225 GLU  ( 225 )
 249 GLU  ( 249 )
 270 GLU  ( 270 )
 291 GLU  ( 291 )
 306 GLU  ( 306 )
 344 GLU  ( 344 )
 355 GLU  ( 355 )
 414 GLU  ( 414 )
 427 GLU  ( 427 )

Note: Heavy atom naming OK

No errors were detected in the atom names for non-hydrogen atoms.

Warning: Chirality deviations detected

The atoms listed in the table below have an improper dihedral value that is deviating from expected values.

Improper dihedrals are a measure of the chirality/planarity of the structure at a specific atom. Values around -35 or +35 are expected for chiral atoms, and values around 0 for planar atoms. Planar side chains are left out of the calculations, these are better handled by the planarity checks.

Three numbers are given for each atom in the table. The first is the Z-score for the improper dihedral. The second number is the measured improper dihedral. The third number is the expected value for this atom type. A final column contains an extra warning if the chirality for an atom is opposite to the expected value.

 113 VAL  ( 113 )      CA      -4.6     23.5     33.6
 199 VAL  ( 199 )      CB       4.4    -22.9    -33.6
 240 VAL  ( 240 )      CA      -4.1     24.6     33.6
 281 LEU  ( 281 )      CA      -4.3     25.1     34.4
 290 VAL  ( 290 )      CA      -5.0     22.6     33.6
 309 THR  ( 309 )      CA      -4.3     24.5     34.2
 429 ILE  ( 429 )      CA      -4.1     25.4     33.8

Note: Improper dihedral angle distribution OK

The RMS Z-score for all improper dihedrals in the structure is within normal ranges.

Improper dihedral RMS Z-score : 0.977

Note: Chain names are OK

All chain names assigned to polymer molecules are unique, and all residue numbers are strictly increasing within each chain.

Note: Weights checked OK

All atomic occupancy factors ('weights') fall in the 0.0--1.0 range.

Geometric checks

Note: No missing atoms detected

All expected atoms are present.

Note: OXT check OK

All required C-terminal oxygen atoms are present.

Note: No extra C-terminal groups found

No C-terminal groups are present for non C-terminal residues

Note: All bond lengths OK

All bond lengths are in agreement with standard bond lengths using a tolerance of 4 sigma (both standard values and sigma for amino acid residues have been taken from Engh and Huber [REF], for DNA/RNA from Parkinson et al [REF])

Note: Normal bond length variability

Bond lengths were found to deviate normally from the standard bond lengths (values for Protein residues were taken from Engh and Huber [REF], for DNA/RNA from Parkinson et al [REF]).

RMS Z-score for bond lengths: 0.759
RMS-deviation in bond distances: 0.016

Note: No bond length directionality

Comparison of bond distances with Engh and Huber [REF] standard values for protein residues and Parkinson et al [REF] values for DNA/RNA does not show significant systematic deviations.

Warning: Unusual bond angles

The bond angles listed in the table below were found to deviate more than 4 sigma from standard bond angles (both standard values and sigma for protein residues have been taken from Engh and Huber [REF], for DNA/RNA from Parkinson et al [REF]). In the table below for each strange angle the bond angle and the number of standard deviations it differs from the standard values is given. Please note that disulphide bridges are neglected. Atoms starting with "<" belong to the previous residue in the sequence.

   7 LEU  (   7 )      C    CA   CB  118.465   4.4
  10 GLU  (  10 )      N    CA   CB  119.077   5.0
  10 GLU  (  10 )      CB   CG   CD  105.500  -4.2
  11 PRO  (  11 )     <O   <C    N   128.031   4.3
  11 PRO  (  11 )     <CA  <C    N   108.809  -5.4
  12 ASP  (  12 )      C    CA   CB  118.272   4.3
  21 ARG  (  21 )     <C    N    CA  130.237   4.7
  21 ARG  (  21 )      N    CA   CB  118.606   4.8
  21 ARG  (  21 )      CA   CB   CG  124.914   5.4
  21 ARG  (  21 )      CD   NE   CZ  135.754   7.8
  21 ARG  (  21 )      NE   CZ   NH1 130.949   5.8
  34 GLU  (  34 )      CA   CB   CG  122.696   4.3
  35 GLU  (  35 )      CG   CD   OE2 107.853  -4.6
  36 ARG  (  36 )      CG   CD   NE  117.479   4.1
  37 ARG  (  37 )      CA   CB   CG  122.603   4.3
  37 ARG  (  37 )      CD   NE   CZ  137.277   8.7
  41 GLN  (  41 )      CB   CG   CD  104.538  -4.7
  41 GLN  (  41 )      NE2  CD   OE1 127.227   4.6
  42 VAL  (  42 )      N    CA   CB  118.229   4.5
  44 THR  (  44 )     <C    N    CA  130.760   5.0
  44 THR  (  44 )      CA   CB   CG2 118.385   4.6
  46 ASN  (  46 )      CA   CB   CG  117.557   5.0
  51 ARG  (  51 )      CD   NE   CZ  129.851   4.5
  52 ASN  (  52 )      C    CA   CB  119.138   4.8
  52 ASN  (  52 )      ND2  CG   OD1 113.582  -9.0
And so on for a total of 212 lines

Note: Normal bond angle variability

Bond angles were found to deviate normally from the mean standard bond angles (normal values for protein residues were taken from Engh and Huber [REF], for DNA/RNA from Parkinson et al [REF]). The RMS Z-score given below is expected to be around 1.0 for a normally restrained data set, and this is indeed observed for very high resolution X-ray structures. More common values are around 1.55

RMS Z-score for bond angles: 1.928
RMS-deviation in bond angles: 3.639

Error: Side chain planarity problems

The side chains of the residues listed in the table below contain a planar group that was found to deviate from planarity by more than 4.0 times the expected value. For an amino acid residue that has a side chain with a planar group, the RMS deviation of the atoms to a least squares plane was determined. The number in the table is the number of standard deviations this RMS value deviates from the expected value (0.0).

 279 ARG  ( 279 )     5.254

Note: Atoms connected to aromatic rings OK

All of the atoms that are connected to planar aromatic rings in side chains of amino-acid residues are in the plane within expected RMS deviations.

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.

   4 PRO  (   4 )     0.15 LOW
 107 PRO  ( 107 )     0.11 LOW
 196 PRO  ( 196 )     0.15 LOW
 236 PRO  ( 236 )     0.14 LOW
 265 PRO  ( 265 )     0.20 LOW

Note: PRO puckering phases OK

Puckering phases for all PRO residues are normal

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.

 363 TRP  ( 363 )   -3.0062
 352 THR  ( 352 )   -2.7884
 348 PRO  ( 348 )   -2.7713
 147 SER  ( 147 )   -2.6014
 237 THR  ( 237 )   -2.4242
  10 GLU  (  10 )   -2.3462
 228 ASP  ( 228 )   -2.2876
 385 VAL  ( 385 )   -2.2753
 229 THR  ( 229 )   -2.1499
 199 VAL  ( 199 )   -2.1345
 326 ILE  ( 326 )   -2.1302
 426 LEU  ( 426 )   -2.1167
 392 GLY  ( 392 )   -2.0891
 225 GLU  ( 225 )   -2.0846
 276 ARG  ( 276 )   -2.0415
  68 ILE  (  68 )   -2.0047

Warning: Backbone torsion angle evaluation shows 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.

  10 GLU  (  10 )   Poor phi/psi
 158 THR  ( 158 )   Poor phi/psi
 161 ARG  ( 161 )   Poor phi/psi
 210 LEU  ( 210 )   PRO omega poor
 211 PRO  ( 211 )   Poor PRO-phi
 226 GLU  ( 226 )   Poor phi/psi
 228 ASP  ( 228 )   Poor phi/psi
 229 THR  ( 229 )   Poor phi/psi
 256 LEU  ( 256 )   PRO omega poor
 257 PRO  ( 257 )   Poor PRO-phi
 265 PRO  ( 265 )   Poor PRO-phi
 275 GLY  ( 275 )   Poor phi/psi
 276 ARG  ( 276 )   Poor phi/psi
 279 ARG  ( 279 )   Poor phi/psi
 280 GLY  ( 280 )   Poor phi/psi
 348 PRO  ( 348 )   Poor PRO-phi
 349 ALA  ( 349 )   Poor phi/psi
 356 ILE  ( 356 )   Poor phi/psi
 363 TRP  ( 363 )   Poor phi/psi
 377 LYS  ( 377 )   Poor phi/psi
 380 LYS  ( 380 )   Poor phi/psi
 392 GLY  ( 392 )   omega poor
 425 GLY  ( 425 )   Poor phi/psi

Note: Ramachandran Z-score OK

The score expressing how well the backbone conformations of all residues are corresponding to the known allowed areas in the Ramachandran plot is within expected ranges for well-refined structures.

Ramachandran Z-score : -1.891

Warning: Omega angles too tightly restrained

The omega angles for trans-peptide bonds in a structure are expected to give a gaussian distribution with the average around +178 degrees and a standard deviation around 5.5 degrees. These expected values were obtained from very accurately determined structures. Many protein structures are too tightly constrained. This seems to be the case with the current structure, as the observed standard deviation is below 4.0 degrees.

Standard deviation of omega values : 1.869

Note: chi-1/chi-2 angle correlation Z-score OK

The score expressing how well the chi-1/chi-2 angles of all residues are corresponding to the populated areas in the database is within expected ranges for well-refined structures.

chi-1/chi-2 correlation Z-score : -2.375

Note: Ramachandran plot

In this Ramachandran plot X-signs represent glycines, squares represent prolines and small plus-signs represent the other residues. If too many plus-signs fall outside the contoured areas then the molecule is poorly refined (or worse).

In a colour picture, the residues that are part of a helix are shown in blue, strand residues in red. "Allowed" regions for helical residues are drawn in blue, for strand residues in red, and for all other residues in green.

Chain without chain identifier

Accessibility related checks

Note: Inside/Outside residue distribution normal

The distribution of residue types over the inside and the outside of the protein is normal.

inside/outside RMS Z-score : 1.009

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 without chain identifier

Secondary structure

Note: Secondary structure

This is the secondary structure according to DSSP. Only helix (H), strand (S), turn (T) and coil (blank) are shown. [REF]
DBG> SSBOND cards to be written: 0
                     10        20        30        40        50        60
                      |         |         |         |         |         |
    1 -  60  MLDPNLLRNEPDAVAEKLARRGFKLDVDKLGALEERRKVLQVKTENLQAERNSRSKSIGQ
    1 -  60     HHHHHH HHHHHHHHHTTT    HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
                     70        80        90       100       110       120
                      |         |         |         |         |         |
   61 - 120  AKARGEDIEPLRLEVNKLGEELDAAKAELDALQAEIRDIALTIPNLPADEVPVGKDENDN
   61 - 120  HHHTT   HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHT      TTT   TT333
                    130       140       150       160       170       180
                      |         |         |         |         |         |
  121 - 180  VEVSRWGTPREFDFEVRDHVTLGEMHSGLDFAAAVKLTGSRFVVMKGQIARMHRALSQFM
  121 - 180  SSSSSST     TT    HHHHHHHTT SSHHHHHHHT TT  SS HHHHHHHHHHHHHH
                    190       200       210       220       230       240
                      |         |         |         |         |         |
  181 - 240  LDLHTEQHGYSENYVPYLVNQDTLYGTGQLPKFAGDLFHTRPLEEEADTSNYALIPTAEV
  181 - 240  HHHHHHTT  SS    TSS HHHHHHHT TTTT333T SS    TT     SSS TTTHH
                    250       260       270       280       290       300
                      |         |         |         |         |         |
  241 - 300  PLTNLVRGEIIDEDDLPIKMTAHTPCFRSEAGSYGRDTRGLIRMHQFDKVEMVQIVRPED
  241 - 300  HHHHTTTT SSS333  SSSSSSSSSS T      TT  T    TSSSSSSSSSSS 333
                    310       320       330       340       350       360
                      |         |         |         |         |         |
  301 - 360  SMAALEEMTGHAEKVLQLLGLPYRKIILCTGDMGFGACKTYDLEVWIPAQNTYREISSCS
  301 - 360  HHHHHHHHHHHHHHHHHHHT  SSSSS  333T TT TSSSSSSSSS333TSSSSSSSSS
                    370       380       390       400       410       420
                      |         |         |         |         |         |
  361 - 420  NVWDFQARRMQARCRSKSDKKTRLVHTLNGSGLAVGRTLVAVMENYQQADGRIEVPEVLR
  361 - 420  S TTHHHHHHT SSS TTT  SSS SSSSSSSSSHHHHHHHHHHHT  TTT SS  TTT3
                    430
                      |
  421 - 430  PYMNGLEYIG
  421 - 430  33TTT  SS
 
 
 

Bump checks

Error: Abnormally short interatomic distances

The pairs of atoms listed in the table below have an unusually short distance.

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 centers of the two atoms.

The last text-item on each line represents the status of the atom pair. The text `INTRA' means that the bump is between atoms that are explicitly listed in the PDB file. `INTER' means it is an inter-symmetry bump. If the final column contains the text 'HB', the bump criterium 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). If the last column is 'BF', the sum of the B-factors of the atoms is higher than 80, which makes the appearance of the bump somewhat less severe because the atoms probably aren't there anyway.

Bumps between atoms for which the sum of their occupancies is lower than one are not reported. In any case, each bump is listed in only one direction.

 361 ASN  ( 361 )      ND2  --  363 TRP  ( 363 )      N      0.432   2.568 INTRA
  10 GLU  (  10 )      N    --   11 PRO  (  11 )      CD     0.345   2.655 INTRA BF
 184 HIS  ( 184 )      ND1  --  188 HIS  ( 188 )      CD2    0.296   2.804 INTRA
 329 CYS  ( 329 )      O    --  330 THR  ( 330 )      C      0.285   2.515 INTRA
 415 VAL  ( 415 )      O    --  416 PRO  ( 416 )      C      0.226   2.574 INTRA
 425 GLY  ( 425 )      O    --  426 LEU  ( 426 )      C      0.213   2.587 INTRA
  10 GLU  (  10 )      O    --   11 PRO  (  11 )      C      0.202   2.598 INTRA BF
  69 GLU  (  69 )      N    --   70 PRO  (  70 )      CD     0.197   2.803 INTRA BF
 305 LEU  ( 305 )      O    --  309 THR  ( 309 )      CG2    0.190   2.610 INTRA
 175 ALA  ( 175 )      O    --  176 LEU  ( 176 )      C      0.175   2.625 INTRA
 361 ASN  ( 361 )      ND2  --  362 VAL  ( 362 )      N      0.152   2.848 INTRA
 348 PRO  ( 348 )      O    --  350 GLN  ( 350 )      N      0.152   2.548 INTRA
 122 GLU  ( 122 )      CD   --  125 ARG  ( 125 )      NH1    0.148   2.952 INTRA
 192 GLU  ( 192 )      C    --  193 ASN  ( 193 )      ND2    0.147   2.953 INTRA
 362 VAL  ( 362 )      O    --  363 TRP  ( 363 )      C      0.143   2.657 INTRA
  34 GLU  (  34 )      CD   --   37 ARG  (  37 )      NH1    0.137   2.963 INTRA BF
 420 ARG  ( 420 )      NH1  --  427 GLU  ( 427 )      CG     0.133   2.967 INTRA BF
 171 ARG  ( 171 )      NH1  --  422 TYR  ( 422 )      O      0.124   2.576 INTRA
 366 GLN  ( 366 )      O    --  367 ALA  ( 367 )      C      0.122   2.678 INTRA
 128 THR  ( 128 )      O    --  129 PRO  ( 129 )      C      0.120   2.680 INTRA
 161 ARG  ( 161 )      CZ   --  282 ILE  ( 282 )      CD1    0.119   3.081 INTRA BF
 244 ASN  ( 244 )      O    --  245 LEU  ( 245 )      C      0.112   2.688 INTRA
   1 MET  (   1 )      N    --  369 ARG  ( 369 )      CG     0.106   2.994 INTRA
 308 MET  ( 308 )      CE   --  388 LEU  ( 388 )      CB     0.103   3.097 INTRA
  55 SER  (  55 )      O    --   56 LYS  (  56 )      C      0.101   2.699 INTRA
And so on for a total of 80 lines

3D-database related checks

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.

 194 TYR  ( 194 )    -8.50
 279 ARG  ( 279 )    -7.33
 223 LEU  ( 223 )    -6.62
 283 ARG  ( 283 )    -5.86
 350 GLN  ( 350 )    -5.58
   9 ASN  (   9 )    -5.38
 115 LYS  ( 115 )    -5.37
 125 ARG  ( 125 )    -5.36
 225 GLU  ( 225 )    -5.17
 276 ARG  ( 276 )    -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, but might also be an indication of misthreading.

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

 223 LEU  ( 223 )     ---  225 GLU  ( 225 )      -5.30

Note: Structural average packing environment OK

The structural average quality control value is within normal ranges.

Average for range 1 - 430 : -0.785

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 without chain identifier

Warning: Low packing Z-score for some residues

The residues listed in the table below have an unusual packing environment according to the 2nd generation quality check. The score listed in the table is a packing normality Z-score: positive means better than average, negative means worse than average. Only residues scoring less than -2.50 are listed here. These are the "unusual" residues in the structure, so it will be interesting to take a special look at them.

 194 TYR  ( 194 )    -2.61
 222 PRO  ( 222 )    -2.56

Warning: Abnormal packing Z-score for sequential residues

A stretch of at least four sequential residues with a 2nd generation packing Z-score below -1.75 was found. This could indicate that these residues are part of a strange loop or that the residues in this range are incomplete, but it might also be an indication of misthreading.

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

 279 ARG  ( 279 )     ---  282 ILE  ( 282 )      -2.08

Note: Structural average packing Z-score OK

The structural average for the second generation quality control value is within normal ranges.

All contacts : Average = -0.094 Z-score = -0.47
BB-BB contacts : Average = 0.151 Z-score = 1.09
BB-SC contacts : Average = -0.325 Z-score = -1.70
SC-BB contacts : Average = -0.017 Z-score = 0.07
SC-SC contacts : Average = -0.250 Z-score = -1.06

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 without chain identifier

Note: Backbone oxygen evaluation OK

All residues for which the local backbone conformation could be found in the WHAT IF database have a normal backbone oxygen position.

Warning: Unusual rotamers

The residues listed in the table below have a rotamer that is not seen very often in the database of solved protein structures. This option determines for every residue the position specific chi-1 rotamer distribution. Thereafter it verified whether the actual residue in the molecule has the most preferred rotamer or not. If the actual rotamer is the preferred one, the score is 1.0. If the actual rotamer is unique, the score is 0.0. If there are two preferred rotamers, with a population distribution of 3:2 and your rotamer sits in the lesser populated rotamer, the score will be 0.66. No value will be given if insufficient hits are found in the database.

It is not necessarily an error if a few residues have rotamer values below 0.3, but careful inspection of all residues with these low values could be worth it.

 389 ASN  ( 389 )     0.38
 289 LYS  ( 289 )     0.38
 125 ARG  ( 125 )     0.38
  55 SER  (  55 )     0.39
 360 SER  ( 360 )     0.40

Warning: Unusual backbone conformations

For the residues listed in the table below, the backbone formed by itself and two neighboring 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 center.

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!

 158 THR  ( 158 )    0
 210 LEU  ( 210 )    0
 228 ASP  ( 228 )    0
 229 THR  ( 229 )    0
 276 ARG  ( 276 )    0
 363 TRP  ( 363 )    0
 377 LYS  ( 377 )    0
 379 ASP  ( 379 )    0
 393 LEU  ( 393 )    0
 147 SER  ( 147 )    1
 166 LYS  ( 166 )    1
 224 GLU  ( 224 )    1
 226 GLU  ( 226 )    1
 256 LEU  ( 256 )    1
 161 ARG  ( 161 )    2
 168 GLN  ( 168 )    2
 227 ALA  ( 227 )    2
 364 ASP  ( 364 )    2

Note: Backbone conformation Z-score OK

The backbone conformation analysis gives a score that is normal for well refined protein structures.

Backbone conformation Z-score : -0.113

B-factor analysis

Note: Average B-factor OK

The average B-factor of buried atoms is within expected values for a room-temperature X-ray study.

Average B-factor for buried atoms : 24.861

Note: Number of buried atoms with low B-factor is OK

For protein structures determined at room temperature, no more than about 1 percent of the B factors of buried atoms is below 5.0.

Percentage of buried atoms with B less than 5 : 0.26

Note: B-factor distribution normal

The distribution of B-factors within residues is within expected ranges. A value over 1.5 here would mean that the B-factors show signs of over-refinement.

RMS Z-score : 0.634 over 2836 bonds
Average difference in B over a bond : 1.84
RMS difference in B over a bond : 2.41

Note: B-factor plot

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

Chain without chain identifier

Hydrogen bond related checks

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 favorable 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. If a residue is marked ``flexible'' the flipped conformation is only slightly better than the non-flipped conformation.

  93 GLN  (  93 )
 188 HIS  ( 188 )
 219 HIS  ( 219 )
 361 ASN  ( 361 )

Note: Histidine type assignments

For all complete HIS residues in the structure a tentative assignment to HIS-D (protonated on ND1), HIS-E (protonated on NE2), or HIS-H (protonated on both ND1 and NE2, positively charged) is made based on the hydrogen bond network. A second assignment is made based on which of the Engh and Huber [REF] histidine geometries fits best to the structure.

In the table below all normal histidine residues are listed. The assignment based on the geometry of the residue is listed first, together with the RMS Z-score for the fit to the Engh and Huber parameters. For all residues where the H-bond assignment is different, the assignment is listed in the last columns, together with its RMS Z-score to the Engh and Huber parameters.

As always, the RMS Z-scores should be close to 1.0 if the residues were restrained to the Engh and Huber parameters during refinement.

Please note that because the differences between the geometries of the different types are small it is possible that the geometric assignment given here does not correspond to the type used in refinement. This is especially true if the RMS Z-scores are much higher than 1.0.

If the two assignments differ, or the ``geometry'' RMS Z-score is high, it is advisable to verify the hydrogen bond assignment, check the HIS type used during the refinement and possibly adjust it.

 139 HIS  ( 139 )     HIS-H   0.38 HIS-D   0.53
 146 HIS  ( 146 )     HIS-H   0.71 HIS-E   0.88
 173 HIS  ( 173 )     HIS-E   1.06
 184 HIS  ( 184 )     HIS-E   0.65
 188 HIS  ( 188 )     HIS-E   1.25 HIS-D   1.26
 219 HIS  ( 219 )     HIS-H   0.50 HIS-E   0.72
 263 HIS  ( 263 )     HIS-E   0.79
 285 HIS  ( 285 )     HIS-E   1.08 HIS-D   1.25
 311 HIS  ( 311 )     HIS-E   0.79
 386 HIS  ( 386 )     HIS-H   0.74 HIS-E   0.82

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.

   1 MET  (   1 )      N
  12 ASP  (  12 )      N
  20 ARG  (  20 )      NE
  44 THR  (  44 )      OG1
 120 ASN  ( 120 )      N
 140 VAL  ( 140 )      N
 162 PHE  ( 162 )      N
 212 LYS  ( 212 )      N
 218 PHE  ( 218 )      N
 226 GLU  ( 226 )      N
 230 SER  ( 230 )      N
 237 THR  ( 237 )      N
 238 ALA  ( 238 )      N
 270 GLU  ( 270 )      N
 279 ARG  ( 279 )      N
 280 GLY  ( 280 )      N
 281 LEU  ( 281 )      N
 286 GLN  ( 286 )      N
 324 ARG  ( 324 )      NE
 340 THR  ( 340 )      N
 352 THR  ( 352 )      N
 353 TYR  ( 353 )      N
 364 ASP  ( 364 )      N
 366 GLN  ( 366 )      N
 367 ALA  ( 367 )      N
 369 ARG  ( 369 )      NE
 369 ARG  ( 369 )      NH2
 377 LYS  ( 377 )      N
 379 ASP  ( 379 )      N
 381 LYS  ( 381 )      N
 412 ARG  ( 412 )      NE
 420 ARG  ( 420 )      N

Note: Buried hydrogen bond acceptors OK

All buried polar side-chain hydrogen bond acceptors are involved in a hydrogen bond in the optimized hydrogen bond network.

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 constraint values. The first part of the table shows a number of constraint-independent quality indicators.


Structure Z-scores, positive is better than average:

  1st generation packing quality :  -0.714
  2nd generation packing quality :  -0.468
  Ramachandran plot appearance   :  -1.891
  chi-1/chi-2 rotamer normality  :  -2.375
  Backbone conformation          :  -0.113

RMS Z-scores, should be close to 1.0:
  Bond lengths                   :   0.759
  Bond angles                    :   1.928
  Omega angle restraints         :   0.340 (tight)
  Side chain planarity           :   0.792
  Improper dihedral distribution :   0.977
  B-factor distribution          :   0.634
  Inside/Outside distribution    :   1.009