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.
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
Coordinate problems, unexpected atoms, B-factor and occupancy checks
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. TLS seems not mentioned in the header of the PDB
file. But anyway, if WHAT IF complains about your B-factors, and 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:
Temperature cannot be read from the PDB file. This most likely means that
the temperature is listed as NULL (meaning unknown) in the PDB file.
Note: B-factor plot
The average atomic B-factor per residue is plotted as function of the residue
Chain identifier: A
Warning: Unusual bond lengths
The bond lengths listed in the table below were found to deviate more than 4
sigma from standard bond lengths (both standard values and sigmas for amino
acid residues have been taken from Engh and Huber [REF], for DNA they were
taken from Parkinson et al [REF]). In the table below for each unusual bond
the bond length and the number of standard deviations it differs from the
normal value is given.
Atom names starting with "-" belong to the previous residue in the chain. If the second atom name is "-SG*", the disulphide bridge has a deviating length.
60 HIS ( 64-) A CG CD2 1.31 -4.3 83 THR ( 87-) A CA CB 1.61 4.1 94 GLY ( 98-) A N CA 1.55 6.0 118 HIS ( 122-) A ND1 CE1 1.38 4.5 172 THR ( 177-) A CB OG1 1.52 5.6 242 PRO ( 247-) A CD N 1.54 4.4
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
| 0.997225 -0.000036 -0.000718| | -0.000036 0.994400 -0.000165| | -0.000718 -0.000165 0.995449|Proposed new scale matrix
| 0.023489 0.000002 0.006145| | 0.000000 0.024116 0.000004| | 0.000010 0.000002 0.014221|With corresponding cell
A = 42.582 B = 41.466 C = 72.700 Alpha= 90.018 Beta= 104.702 Gamma= 90.002
The CRYST1 cell dimensions
A = 42.700 B = 41.700 C = 73.000 Alpha= 90.000 Beta= 104.600 Gamma= 90.000
(Under-)estimated Z-score: 9.608
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.
6 HIS ( 10-) A CA CB CG 106.80 -7.0 10 GLU ( 14-) A CA CB CG 129.76 7.8 10 GLU ( 14-) A CB CG CD 123.17 6.2 15 ASP ( 19-) A C CA CB 102.45 -4.0 16 PHE ( 20-) A -O -C N 129.70 4.2 17 PRO ( 21-) A -O -C N 128.07 4.3 17 PRO ( 21-) A -CA -C N 110.77 -4.1 20 LYS ( 24-) A N CA CB 117.73 4.3 20 LYS ( 24-) A CA CB CG 132.36 9.1 22 GLU ( 26-) A CA C O 113.03 -4.6 23 ARG ( 27-) A CA CB CG 124.76 5.3 31 THR ( 35-) A N CA CB 102.74 -4.6 32 HIS ( 36-) A CG ND1 CE1 110.76 5.2 33 THR ( 37-) A -C N CA 130.86 5.1 33 THR ( 37-) A CA CB CG2 120.17 5.7 33 THR ( 37-) A CA CB OG1 102.70 -4.6 36 TYR ( 40-) A CA CB CG 105.77 -4.1 47 TYR ( 51-) A CA CB CG 122.46 4.7 49 GLN ( 53-) A N CA CB 103.24 -4.3 54 ARG ( 58-) A CD NE CZ 136.55 8.3 55 ILE ( 59-) A -CA -C N 107.80 -4.2 55 ILE ( 59-) A C CA CB 118.80 4.6 57 ASN ( 61-) A C CA CB 119.10 4.7 60 HIS ( 64-) A N CA CB 117.30 4.0 60 HIS ( 64-) A NE2 CD2 CG 111.25 4.7And so on for a total of 95 lines.
123 TYR ( 128-) A 5.75 35 LYS ( 39-) A 5.30 203 THR ( 208-) A 5.11 161 SER ( 166-) A 4.81 64 VAL ( 68-) A 4.51 73 ALA ( 77-) A 4.00
Tau angle RMS Z-score : 1.704
Warning: Torsion angle evaluation shows unusual residues
The residues listed in the table below contain bad or abnormal
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.
54 ARG ( 58-) A -2.7 150 PRO ( 155-) A -2.3 162 ILE ( 167-) A -2.1 79 PRO ( 83-) A -2.1 190 PRO ( 195-) A -2.1 75 LEU ( 79-) A -2.1 88 GLN ( 92-) A -2.1 158 VAL ( 163-) A -2.0
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.
25 SER ( 29-) A PRO omega poor 61 ALA ( 65-) A Poor phi/psi 107 LYS ( 111-) A Poor phi/psi 173 ASN ( 178-) A Poor phi/psi 196 PRO ( 201-) A PRO omega poor 248 ASN ( 253-) A Poor phi/psi chi-1/chi-2 correlation Z-score : -1.885
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!
3 TYR ( 7-) A 0 6 HIS ( 10-) A 0 15 ASP ( 19-) A 0 16 PHE ( 20-) A 0 20 LYS ( 24-) A 0 23 ARG ( 27-) A 0 24 GLN ( 28-) A 0 25 SER ( 29-) A 0 46 SER ( 50-) A 0 50 ALA ( 54-) A 0 54 ARG ( 58-) A 0 58 ASN ( 62-) A 0 60 HIS ( 64-) A 0 68 ASP ( 72-) A 0 69 SER ( 73-) A 0 71 ASP ( 75-) A 0 72 LYS ( 76-) A 0 73 ALA ( 77-) A 0 76 LYS ( 80-) A 0 79 PRO ( 83-) A 0 81 ASP ( 85-) A 0 88 GLN ( 92-) A 0 99 GLN ( 103-) A 0 102 GLU ( 106-) A 0 103 HIS ( 107-) A 0And so on for a total of 112 lines.
Standard deviation of omega values : 1.836
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]
38 PRO ( 42-) A 0.17 LOW 176 PRO ( 181-) A 0.08 LOW 181 PRO ( 186-) A 0.11 LOW 197 PRO ( 202-) A 0.46 HIGH
190 PRO ( 195-) A -10.4 half-chair C-alpha/N (-18 degrees)
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.
11 HIS ( 15-) A ND1 <-> 14 LYS ( 18-) A NZ 0.56 2.44 INTRA BL 54 ARG ( 58-) A CD <-> 65 GLU ( 69-) A OE1 0.34 2.46 INTRA BL 58 ASN ( 62-) A O <-> 165 LYS ( 170-) A NZ 0.33 2.37 INTRA BL 71 ASP ( 75-) A OD1 <-> 85 ARG ( 89-) A NE 0.32 2.38 INTRA BL 109 LYS ( 113-) A NZ <-> 257 HOH ( 345 ) A O 0.28 2.42 INTRA BL 163 LYS ( 168-) A NZ <-> 257 HOH ( 332 ) A O 0.28 2.42 INTRA 3 TYR ( 7-) A N <-> 257 HOH ( 281 ) A O 0.23 2.47 INTRA BL 60 HIS ( 64-) A ND1 <-> 257 HOH ( 322 ) A O 0.22 2.48 INTRA BL 99 GLN ( 103-) A NE2 <-> 238 ASP ( 243-) A OD1 0.21 2.49 INTRA BL 185 ASP ( 190-) A OD2 <-> 208 LYS ( 213-) A NZ 0.20 2.50 INTRA BL 247 LYS ( 252-) A O <-> 248 ASN ( 253-) A CG 0.19 2.51 INTRA BL 248 ASN ( 253-) A ND2 <-> 249 ARG ( 254-) A N 0.19 2.56 INTRA BL 175 ASP ( 180-) A OD2 <-> 177 ARG ( 182-) A NH2 0.19 2.51 INTRA BL 47 TYR ( 51-) A OH <-> 118 HIS ( 122-) A NE2 0.18 2.52 INTRA BL 60 HIS ( 64-) A NE2 <-> 257 HOH ( 346 ) A O 0.17 2.53 INTRA 25 SER ( 29-) A O <-> 241 ARG ( 246-) A NH1 0.17 2.53 INTRA BL 22 GLU ( 26-) A N <-> 257 HOH ( 272 ) A O 0.15 2.55 INTRA BL 54 ARG ( 58-) A CD <-> 65 GLU ( 69-) A CD 0.15 3.05 INTRA BL 140 GLY ( 145-) A N <-> 205 ILE ( 210-) A O 0.15 2.55 INTRA BL 84 TYR ( 88-) A OH <-> 257 HOH ( 288 ) A O 0.15 2.25 INTRA BL 113 GLU ( 117-) A OE2 <-> 115 HIS ( 119-) A NE2 0.13 2.57 INTRA BL 85 ARG ( 89-) A NH2 <-> 257 HOH ( 365 ) A O 0.12 2.58 INTRA 54 ARG ( 58-) A O <-> 65 GLU ( 69-) A N 0.11 2.59 INTRA BL 183 SER ( 188-) A N <-> 209 GLU ( 214-) A OE1 0.10 2.60 INTRA BL 92 HIS ( 96-) A ND1 <-> 239 ASN ( 244-) A O 0.10 2.60 INTRA BLAnd so on for a total of 60 lines.
Chain identifier: A
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.
6 HIS ( 10-) A -5.96 131 GLN ( 136-) A -5.18
Chain identifier: A
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
Water, ion, and hydrogenbond related checks
Warning: Water molecules need moving
The water molecules listed in the table below were found to be significantly
closer to a symmetry related non-water molecule than to the ones given in the
coordinate file. For optimal viewing convenience revised coordinates for
these water molecules should be given.
The number in brackets is the identifier of the water molecule in the input file. Suggested coordinates are also given in the table. Please note that alternative conformations for protein residues are not taken into account for this calculation. If you are using WHAT IF / WHAT-CHECK interactively, then the moved waters can be found in PDB format in the file: MOVEDH2O.pdb.
257 HOH ( 293 ) A O -13.95 -18.85 15.19
257 HOH ( 268 ) A O 257 HOH ( 309 ) A O 257 HOH ( 333 ) A O 257 HOH ( 348 ) A O Metal-coordinating Histidine residue 90 fixed to 1 Metal-coordinating Histidine residue 92 fixed to 1 Metal-coordinating Histidine residue 115 fixed to 1
6 HIS ( 10-) A 173 ASN ( 178-) A
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.
27 VAL ( 31-) A N 41 LYS ( 45-) A N 49 GLN ( 53-) A N 96 LEU ( 100-) A N 177 ARG ( 182-) A NE 199 LEU ( 204-) A N 216 GLU ( 221-) A N 239 ASN ( 244-) A ND2 240 TRP ( 245-) A N Only metal coordination for 92 HIS ( 96-) A NE2 Only metal coordination for 115 HIS ( 119-) A ND1
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.
65 GLU ( 69-) A OE1
10 GLU ( 14-) A H-bonding suggests Gln 81 ASP ( 85-) A H-bonding suggests Asn; but Alt-Rotamer
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 : -0.184 2nd generation packing quality : 0.188 Ramachandran plot appearance : -1.961 chi-1/chi-2 rotamer normality : -1.885 Backbone conformation : -0.913
Bond lengths : 1.360 Bond angles : 1.809 Omega angle restraints : 0.334 (tight) Side chain planarity : 1.433 Improper dihedral distribution : 1.341 B-factor distribution : 0.356 Inside/Outside distribution : 0.949
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 : 2.20
Structure Z-scores, positive is better than average:
1st generation packing quality : 0.4 2nd generation packing quality : 0.4 Ramachandran plot appearance : -0.6 chi-1/chi-2 rotamer normality : -0.6 Backbone conformation : -0.8
Bond lengths : 1.360 Bond angles : 1.809 Omega angle restraints : 0.334 (tight) Side chain planarity : 1.433 Improper dihedral distribution : 1.341 B-factor distribution : 0.356 Inside/Outside distribution : 0.949 ==============
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.