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.
326 DMS ( 374-) A -
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: Occupancies atoms do not add up to 1.0.
In principle, the occupancy of all alternates of one atom should add up till
1.0. A valid exception is the missing atom (i.e. an atom not seen in the
electron density) that is allowed to have a 0.0 occupancy. Sometimes this
even happens when there are no alternate atoms given...
Atoms want to move. That is the direct result of the second law of thermodynamics, in a somewhat weird way of thinking. Any way, many atoms seem to have more than one position where they like to sit, and they jump between them. The population difference between those sites (which is related to their energy differences) is seen in the occupancy factors. As also for atoms it is 'to be or not to be', these occupancies should add up to 1.0. Obviously, it is possible that they add up to a number less than 1.0, in cases where there are yet more, but undetected' rotamers/positions in play, but also in those cases a warning is in place as the information shown in the PDB file is less certain than it could have been. The residues listed below contain atoms that have an occupancy greater than zero, but all their alternates do not add up to one.
WARNING. Presently WHAT CHECK only deals with a maximum of two alternate positions. A small number of atoms in the PDB has three alternates. In those cases the warning given here should obviously be neglected! In a next release we will try to fix this.
144 LEU ( 144-) A 0.50 157 TYR ( 157-) A 0.80 225 GLN ( 225-) A 0.50
Obviously, the temperature at which the X-ray data was collected has some importance too:
Crystal temperature (K) :298.000
Note: B-factor plot
The average atomic B-factor per residue is plotted as function of the residue
Chain identifier: A
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
| 0.996836 -0.000096 -0.000729| | -0.000096 0.998085 -0.000475| | -0.000729 -0.000475 0.998234|Proposed new scale matrix
| 0.010694 0.006167 0.000011| | 0.000001 0.012333 0.000006| | 0.000006 0.000004 0.007642|With corresponding cell
A = 93.512 B = 93.606 C = 130.864 Alpha= 90.005 Beta= 90.084 Gamma= 119.975
The CRYST1 cell dimensions
A = 93.811 B = 93.811 C = 131.101 Alpha= 90.000 Beta= 90.000 Gamma= 120.000
(Under-)estimated Z-score: 5.560
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.
1 ILE ( 1-) A CA CB CG2 117.42 4.1 2 THR ( 2-) A CA C O 113.50 -4.3 5 SER ( 5-) A CA CB OG 101.94 -4.6 14 LEU ( 14-) A -O -C N 115.40 -4.7 14 LEU ( 14-) A CA C O 112.47 -4.9 17 GLN ( 17-) A CB CG CD 119.49 4.1 18 LYS ( 18-) A CG CD CE 122.38 4.8 19 ASN ( 19-) A CA CB CG 105.64 -7.0 19 ASN ( 19-) A ND2 CG OD1 117.49 -5.1 21 ASN ( 21-) A CA CB CG 108.37 -4.2 33 ASN ( 33-) A ND2 CG OD1 118.35 -4.3 40 PHE ( 40-) A -C N CA 129.54 4.4 47 ARG ( 47-) A CA CB CG 102.15 -6.0 47 ARG ( 47-) A CD NE CZ 137.12 8.6 53 SER ( 53-) A C CA CB 101.83 -4.4 57 ASP ( 57-) A N CA CB 101.85 -5.1 57 ASP ( 57-) A CA CB CG 105.03 -7.6 58 ALA ( 58-) A CA C O 113.91 -4.1 59 ASP ( 59-) A CB CG OD2 129.62 4.9 60 ASN ( 60-) A ND2 CG OD1 118.55 -4.1 61 GLN ( 61-) A CA C O 110.92 -5.8 62 PHE ( 62-) A -O -C N 116.43 -4.1 62 PHE ( 62-) A -CA -C N 131.06 7.4 67 ASP ( 67-) A C CA CB 102.46 -4.0 69 PRO ( 69-) A N CA CB 109.02 5.5And so on for a total of 83 lines.
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.
25 SER ( 25-) A C -7.1 -11.33 0.37 115 TRP ( 115-) A C -6.0 -8.61 0.23 126 ASP ( 126-) A C -7.0 -10.78 -0.01 189 GLY ( 189-) A C 10.1 13.43 0.06 199 GLY ( 199-) A C -6.5 -8.55 0.06 228 GLY ( 228-) A C -8.0 -10.56 0.06 259 GLY ( 259-) A C 10.4 13.73 0.06 264 GLY ( 264-) A C 6.3 8.34 0.06 The average deviation= 2.030
216 HIS ( 216-) A 6.64 19 ASN ( 19-) A 6.33 138 ASP ( 138-) A 4.34
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.
6 THR ( 6-) A -2.7 157 TYR ( 157-) A -2.6 182 LYS ( 182-) A -2.4 46 TYR ( 46-) A -2.4 92 SER ( 92-) A -2.4 20 ILE ( 20-) A -2.4 107 SER ( 107-) A -2.3 119 GLU ( 119-) A -2.1
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.
26 THR ( 26-) A Poor phi/psi 45 LYS ( 45-) A Poor phi/psi 46 TYR ( 46-) A Poor phi/psi 50 LEU ( 50-) A PRO omega poor 60 ASN ( 60-) A Poor phi/psi 89 ASN ( 89-) A Poor phi/psi 92 SER ( 92-) A Poor phi/psi 97 ASN ( 97-) A Poor phi/psi 107 SER ( 107-) A Poor phi/psi 118 SER ( 118-) A Poor phi/psi 132 PRO ( 132-) A omega poor 152 THR ( 152-) A Poor phi/psi 157 TYR ( 157-) A Poor phi/psi 159 ASN ( 159-) A Poor phi/psi 194 THR ( 194-) A Poor phi/psi chi-1/chi-2 correlation Z-score : -0.379
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.
169 SER ( 169-) A 0.36 291 SER ( 291-) A 0.36
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!
5 SER ( 5-) A 0 14 LEU ( 14-) A 0 19 ASN ( 19-) A 0 24 TYR ( 24-) A 0 25 SER ( 25-) A 0 26 THR ( 26-) A 0 27 TYR ( 27-) A 0 34 THR ( 34-) A 0 35 ARG ( 35-) A 0 37 ASP ( 37-) A 0 45 LYS ( 45-) A 0 46 TYR ( 46-) A 0 49 THR ( 49-) A 0 51 PRO ( 51-) A 0 53 SER ( 53-) A 0 55 TRP ( 55-) A 0 58 ALA ( 58-) A 0 60 ASN ( 60-) A 0 61 GLN ( 61-) A 0 62 PHE ( 62-) A 0 63 PHE ( 63-) A 0 91 LEU ( 91-) A 0 92 SER ( 92-) A 0 96 ASN ( 96-) A 0 104 VAL ( 104-) A 0And so on for a total of 124 lines.
For each of the residues in the structure, a search was performed to find 5-residue stretches in the WHAT IF database with superposable C-alpha coordinates, and some restraining on the neighbouring backbone oxygens.
In the following table the RMS distance between the backbone oxygen positions of these matching structures in the database and the position of the backbone oxygen atom in the current residue is given. If this number is larger than 1.5 a significant number of structures in the database show an alternative position for the backbone oxygen. If the number is larger than 2.0 most matching backbone fragments in the database have the peptide plane flipped. A manual check needs to be performed to assess whether the experimental data can support that alternative as well. The number in the last column is the number of database hits (maximum 80) used in the calculation. It is "normal" that some glycine residues show up in this list, but they are still worth checking!
277 PRO ( 277-) A 1.82 11
208 PRO ( 208-) A 0.19 LOW
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.
120 MET ( 120-) A A SD <-> 143 GLU ( 143-) A CB 0.69 2.71 INTRA 111 ASN ( 111-) A O <-> 318 LYS ( 507-) A NZ 0.42 2.28 INTRA BF 120 MET ( 120-) A A CE <-> 143 GLU ( 143-) A CB 0.20 3.00 INTRA BL 157 TYR ( 157-) A A OH <-> 166 GLU ( 166-) A OE2 0.18 2.22 INTRA 126 ASP ( 126-) A OD1 <-> 128 GLN ( 128-) A N 0.16 2.54 INTRA 16 ASP ( 16-) A OD2 <-> 18 LYS ( 18-) A NZ 0.15 2.55 INTRA 9 VAL ( 9-) A O <-> 62 PHE ( 62-) A N 0.15 2.55 INTRA BL 262 LYS ( 262-) A NZ <-> 302 GLU ( 302-) A OE2 0.13 2.57 INTRA 226 ASP ( 226-) A OD1 <-> 231 HIS ( 231-) A ND1 0.12 2.58 INTRA 217 TYR ( 217-) A N <-> 313 VAL ( 313-) A O 0.10 2.60 INTRA BL 68 ALA ( 68-) A N <-> 69 PRO ( 69-) A CD 0.10 2.90 INTRA BL 130 PHE ( 130-) A CE2 <-> 318 LYS ( 507-) A NZ 0.08 3.02 INTRA BF 4 THR ( 4-) A O <-> 24 TYR ( 24-) A N 0.08 2.62 INTRA BL 18 LYS ( 18-) A NZ <-> 72 ASP ( 72-) A OD1 0.07 2.63 INTRA BL 243 LEU ( 243-) A O <-> 247 GLY ( 247-) A N 0.07 2.63 INTRA 206 SER ( 206-) A O <-> 239 LYS ( 239-) A NZ 0.07 2.63 INTRA 129 THR ( 129-) A O <-> 194 THR ( 194-) A N 0.06 2.64 INTRA 13 VAL ( 13-) A N <-> 72 ASP ( 72-) A OD2 0.06 2.64 INTRA BL 226 ASP ( 226-) A OD2 <-> 231 HIS ( 231-) A N 0.05 2.65 INTRA 292 ALA ( 292-) A O <-> 296 TYR ( 296-) A N 0.04 2.66 INTRA 28 TYR ( 28-) A O <-> 57 ASP ( 57-) A N 0.04 2.66 INTRA BL 182 LYS ( 182-) A O <-> 183 ASN ( 183-) A C 0.03 2.57 INTRA 81 TYR ( 81-) A OH <-> 97 ASN ( 97-) A ND2 0.03 2.67 INTRA BL 112 ASN ( 112-) A ND2 <-> 318 LYS ( 507-) A O 0.02 2.68 INTRA BF 72 ASP ( 72-) A O <-> 76 TYR ( 76-) A N 0.02 2.68 INTRA BL 53 SER ( 53-) A C <-> 54 LEU ( 54-) A C 0.01 2.79 INTRA BL 142 HIS ( 142-) A ND1 <-> 170 ASP ( 170-) A OD1 0.01 2.69 INTRA BL 138 ASP ( 138-) A OD2 <-> 189 GLY ( 189-) A N 0.01 2.69 INTRA BL 126 ASP ( 126-) A N <-> 127 GLY ( 127-) A N 0.01 2.59 INTRA B3 131 ILE ( 131-) A CB <-> 132 PRO ( 132-) A CD 0.01 3.09 INTRA 149 THR ( 149-) A O <-> 154 GLY ( 154-) A N 0.01 2.69 INTRA BL 227 ASN ( 227-) A ND2 <-> 327 HOH ( 666 ) A O 0.01 2.69 INTRA BF
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.
108 GLN ( 108-) A -5.97 88 HIS ( 88-) A -5.84 221 TYR ( 221-) A -5.79 182 LYS ( 182-) A -5.63 246 GLN ( 246-) A -5.52 251 TYR ( 251-) A -5.44 225 GLN ( 225-) A -5.31 273 GLN ( 273-) A -5.20
Chain identifier: A
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 packing 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.
44 ALA ( 44-) A -2.76
Chain identifier: A
Water, ion, and hydrogenbond 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 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.
19 ASN ( 19-) A 31 GLN ( 31-) A 33 ASN ( 33-) A 96 ASN ( 96-) A 290 GLN ( 290-) A 301 GLN ( 301-) 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.
35 ARG ( 35-) A N 97 ASN ( 97-) A ND2 112 ASN ( 112-) A N 138 ASP ( 138-) A N 155 LEU ( 155-) A N 206 SER ( 206-) A N 209 ALA ( 209-) A N 216 HIS ( 216-) A N 318 LYS ( 507-) A NZ Only metal coordination for 142 HIS ( 142-) A NE2
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.
238 ASN ( 238-) A OD1
The output gives the ion, the valency score for the ion itself, the valency score for the suggested alternative ion, and a series of possible comments *1 indicates that the suggested alternate atom type has been observed in the PDB file at another location in space. *2 indicates that WHAT IF thinks to have found this ion type in the crystallisation conditions as described in the REMARK 280 cards of the PDB file. *S Indicates that this ions is located at a special position (i.e. at a symmetry axis). N4 stands for NH4+.
321 CA ( 502-) A -.- -.- Part of ionic cluster 321 CA ( 502-) A 0.47 1.34 Is perhaps K 322 CA ( 503-) A -.- -.- Part of ionic cluster 322 CA ( 503-) A 0.57 0.79 Scores about as good as NA 323 CA ( 504-) A 0.52 0.74 Scores about as good as NA 324 CA ( 505-) A 0.46 1.28 Is perhaps K
37 ASP ( 37-) A H-bonding suggests Asn 119 GLU ( 119-) A H-bonding suggests Gln 294 ASP ( 294-) 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 : -0.904 2nd generation packing quality : -1.413 Ramachandran plot appearance : -0.095 chi-1/chi-2 rotamer normality : -0.379 Backbone conformation : -0.339
Bond lengths : 0.669 Bond angles : 1.557 Omega angle restraints : 0.789 Side chain planarity : 1.633 Improper dihedral distribution : 1.794 (loose) B-factor distribution : 1.125 Inside/Outside distribution : 1.017
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 : -0.2 2nd generation packing quality : -0.6 Ramachandran plot appearance : 1.0 chi-1/chi-2 rotamer normality : 0.8 Backbone conformation : -0.3
Bond lengths : 0.669 Bond angles : 1.557 Omega angle restraints : 0.789 Side chain planarity : 1.633 Improper dihedral distribution : 1.794 (loose) B-factor distribution : 1.125 Inside/Outside distribution : 1.017 ==============
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.