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.
Alternate atom indicators in PDB files are known to often be erroneous. It has been observed that alternate atom indicators are missing, or that there are too many of them. It is common to see that the distance between two atoms that should be covalently bound is far too big, but the distance between the alternate A of one of them and alternate B of the other is proper for a covalent bond. We have discovered many, many ways in which alternate atoms can be abused. The software tries to deal with most cases, but we know for sure that it cannot deal with all cases. If an alternate atom indicator problem is not properly solved, subsequent checks will list errors that are based on wrong coordinate combinations. So, any problem listed in this table should be solved before error messages further down in this report can be trusted.
69 VAL ( 101-) A - 136 ILE ( 168-) A -
In case any of these residues shows up as poor or bad in checks further down this report, please check the consistency of the alternate atoms in this residue first, correct it yourself if needed, and run the validation again.
69 VAL ( 101-) A - 136 ILE ( 168-) A -
Plausible side chain atoms were detected with (near) zero occupancy
When crystallographers do not see an atom they either leave it out completely, or give it an occupancy of zero or a very high B-factor. WHAT IF neglects these atoms. In this case some atoms were found with zero occupancy, but with coordinates that place them at a plausible position. Although WHAT IF knows how to deal with missing side chain atoms, validation will go more reliable if all atoms are presnt. So, please consider manually setting the occupancy of the listed atoms at 1.0.
47 LYS ( 79-) A - CD 47 LYS ( 79-) A - CE 47 LYS ( 79-) A - NZ 55 LYS ( 87-) A - CE 55 LYS ( 87-) A - NZ 78 LYS ( 110-) A - CD 78 LYS ( 110-) A - CE 78 LYS ( 110-) A - NZ
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:
Crystal temperature (K) :100.000
Note: B-factor plot
The average atomic B-factor per residue is plotted as function of the residue
Chain identifier: A
Warning: Low bond length variability
Bond lengths were found to deviate less than normal from the mean Engh and
Huber [REF] and/or Parkinson et al [REF] standard bond lengths. The RMS
Z-score given below is expected to be near 1.0 for a normally restrained
data set. The fact that it is lower than 0.667 in this structure might
indicate that too-strong restraints have been used in the refinement. This
can only be a problem for high resolution X-ray structures.
RMS Z-score for bond lengths: 0.252
RMS-deviation in bond distances: 0.005
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.
4 HIS ( 36-) A CG ND1 CE1 109.66 4.1 71 ASP ( 103-) A CA CB CG 116.81 4.2 85 ASN ( 117-) A CA CB CG 116.67 4.1
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.
78 LYS ( 110-) A -2.3 121 GLY ( 153-) A -2.2 52 ILE ( 84-) 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.
50 PRO ( 82-) A omega poor 82 PHE ( 114-) A omega poor 104 TRP ( 136-) A omega poor 113 ALA ( 145-) A Poor phi/psi 126 TYR ( 158-) A Poor phi/psi 131 PHE ( 163-) A omega poor 140 ASP ( 172-) A Poor phi/psi chi-1/chi-2 correlation Z-score : 0.598
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!
26 GLN ( 58-) A 0 29 ALA ( 61-) A 0 34 SER ( 66-) A 0 40 ARG ( 72-) A 0 48 ARG ( 80-) A 0 64 LEU ( 96-) A 0 70 PHE ( 102-) A 0 71 ASP ( 103-) A 0 76 ARG ( 108-) A 0 86 GLU ( 118-) A 0 87 VAL ( 119-) A 0 88 ILE ( 120-) A 0 100 GLU ( 132-) A 0 104 TRP ( 136-) A 0 112 LEU ( 144-) A 0 113 ALA ( 145-) A 0 114 TYR ( 146-) A 0 116 VAL ( 148-) A 0 117 THR ( 149-) A 0 119 GLY ( 151-) A 0 122 MET ( 154-) A 0 137 SER ( 169-) A 0 139 LYS ( 171-) A 0 140 ASP ( 172-) A 0 145 ARG ( 177-) A 0 47 LYS ( 79-) A 1 52 ILE ( 84-) A 1 59 HIS ( 91-) A 1 72 SER ( 104-) A 1 83 ARG ( 115-) A 1 98 MET ( 130-) A 1 99 ARG ( 131-) A 1 125 PRO ( 157-) A 1 126 TYR ( 158-) A 1 136 ILE ( 168-) A 1 143 LYS ( 175-) A 1 42 ALA ( 74-) A 2 45 SER ( 77-) A 2 49 ALA ( 81-) A 2 53 ASP ( 85-) A 2 66 ASP ( 98-) A 2 73 SER ( 105-) A 2 78 LYS ( 110-) A 2 97 LEU ( 129-) A 2 102 ASP ( 134-) A 2 123 ILE ( 155-) A 2 127 SER ( 159-) A 2 138 ILE ( 170-) A 2 141 GLY ( 173-) A 2
125 PRO ( 157-) A 104.9 envelop C-beta (108 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.
105 ARG ( 137-) A NE <-> 161 HOH (1164 ) A O 0.21 2.49 INTRA BF 63 ARG ( 95-) A A NH1 <-> 67 GLY ( 99-) A O 0.20 2.50 INTRA BL 83 ARG ( 115-) A NE <-> 161 HOH (1211 ) A O 0.20 2.50 INTRA 156 LYS ( 188-) A NZ <-> 161 HOH (1179 ) A O 0.20 2.50 INTRA BF 152 GLU ( 184-) A OE2 <-> 155 ARG ( 187-) A NH2 0.16 2.54 INTRA 3 SER ( 35-) A OG <-> 7 ARG ( 39-) A NH1 0.11 2.59 INTRA 3 SER ( 35-) A CB <-> 7 ARG ( 39-) A NH1 0.10 3.00 INTRA 137 SER ( 169-) A OG <-> 161 HOH (1107 ) A O 0.10 2.30 INTRA 22 GLN ( 54-) A NE2 <-> 161 HOH (1236 ) A O 0.09 2.61 INTRA 2 ALA ( 34-) A N <-> 161 HOH (1206 ) A O 0.09 2.61 INTRA 120 GLY ( 152-) A N <-> 161 HOH (1066 ) A O 0.08 2.62 INTRA 41 ILE ( 73-) A N <-> 103 ARG ( 135-) A O 0.08 2.62 INTRA BL 39 GLN ( 71-) A OE1 <-> 161 HOH (1212 ) A O 0.06 2.34 INTRA 83 ARG ( 115-) A NH1 <-> 86 GLU ( 118-) A OE2 0.04 2.66 INTRA 48 ARG ( 80-) A NH2 <-> 144 GLY ( 176-) A O 0.04 2.66 INTRA 56 CYS ( 88-) A N <-> 82 PHE ( 114-) A O 0.03 2.67 INTRA BL 48 ARG ( 80-) A NH2 <-> 143 LYS ( 175-) A C 0.03 3.07 INTRA 151 ASP ( 183-) A OD2 <-> 161 HOH (1174 ) A O 0.02 2.38 INTRA 43 ARG ( 75-) A N <-> 161 HOH (1077 ) A O 0.01 2.69 INTRA
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.
65 ARG ( 97-) A -6.90 43 ARG ( 75-) A -6.83 122 MET ( 154-) A -6.05 114 TYR ( 146-) A -5.71 76 ARG ( 108-) A -5.62 126 TYR ( 158-) A -5.50 86 GLU ( 118-) A -5.06
The table below lists the first and last residue in each stretch found, as well as the average residue score of the series.
139 LYS ( 171-) A 141 - GLY 173- ( A) -4.11
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.
161 HOH (1068 ) A O 20.95 25.39 1.96 161 HOH (1069 ) A O 24.50 -6.19 2.66 161 HOH (1115 ) A O 0.66 -16.85 27.32 161 HOH (1121 ) A O 14.12 -5.21 0.83 161 HOH (1155 ) A O 3.62 4.33 23.23 161 HOH (1165 ) A O 13.46 22.14 1.76 161 HOH (1190 ) A O 21.29 -9.56 4.27 161 HOH (1198 ) A O 24.34 16.99 9.44 161 HOH (1219 ) A O 16.54 5.83 28.75 161 HOH (1220 ) A O 2.28 9.48 17.76 161 HOH (1226 ) A O 16.79 -16.80 26.60 161 HOH (1234 ) A O 16.87 -8.48 4.25 161 HOH (1248 ) A O 18.05 -18.50 14.74 161 HOH (1262 ) A O 33.90 -9.66 11.31 161 HOH (1271 ) A O 2.31 1.55 22.25 161 HOH (1272 ) A O 9.30 12.39 -11.49
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.
48 ARG ( 80-) A N 60 TYR ( 92-) A N 85 ASN ( 117-) A ND2
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.
161 HOH (1035 ) A O 0.97 K 4 161 HOH (1046 ) A O 1.15 K 4 161 HOH (1069 ) A O 1.10 K 4
160 ASP ( 192-) A H-bonding suggests Asn
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 : 0.226 2nd generation packing quality : -0.104 Ramachandran plot appearance : 0.164 chi-1/chi-2 rotamer normality : 0.598 Backbone conformation : 0.550
Bond lengths : 0.252 (tight) Bond angles : 0.876 Omega angle restraints : 1.067 Side chain planarity : 0.350 (tight) Improper dihedral distribution : 0.606 B-factor distribution : 1.215 Inside/Outside distribution : 0.974
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 : 1.70
Structure Z-scores, positive is better than average:
1st generation packing quality : 0.3 2nd generation packing quality : -0.6 Ramachandran plot appearance : -0.2 chi-1/chi-2 rotamer normality : 0.6 Backbone conformation : 0.1
Bond lengths : 0.252 (tight) Bond angles : 0.876 Omega angle restraints : 1.067 Side chain planarity : 0.350 (tight) Improper dihedral distribution : 0.606 B-factor distribution : 1.215 Inside/Outside distribution : 0.974 ==============
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.