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.
259 2C7 ( 300-) 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: 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
Warning: More than 5 percent of buried atoms has low B-factor
For normal protein structures, no more than about 1 percent of the B factors
of buried atoms is below 5.0. The fact that this value is much higher in the
current structure could be a signal that the B-factors were restraints or
constraints to too-low values, misuse of B-factor field in the PDB file, or
a TLS/scaling problem. If the average B factor is low too, it is probably a
low temperature structure determination.
Percentage of buried atoms with B less than 5 : 46.30
Note: B-factor plot
The average atomic B-factor per residue is plotted as function of the residue
Chain identifier: A
Nomenclature related problems
Warning: Tyrosine convention problem
The tyrosine residues listed in the table below have their chi-2 not between
-90.0 and 90.0
4 TYR ( 7-) A 37 TYR ( 40-) A 48 TYR ( 51-) A 85 TYR ( 88-) A 124 TYR ( 128-) A 190 TYR ( 194-) A
127 PHE ( 131-) A 227 PHE ( 231-) A
29 ASP ( 32-) A 38 ASP ( 41-) A 69 ASP ( 72-) A 82 ASP ( 85-) A 98 ASP ( 101-) A 107 ASP ( 110-) A 135 ASP ( 139-) A 176 ASP ( 180-) A 186 ASP ( 190-) A 239 ASP ( 243-) A
11 GLU ( 14-) A 183 GLU ( 187-) A 210 GLU ( 214-) A 217 GLU ( 221-) A 230 GLU ( 234-) A 234 GLU ( 238-) A
RMS Z-score for bond lengths: 0.425
RMS-deviation in bond distances: 0.010
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
| 0.997285 0.000304 -0.000283| | 0.000304 0.998414 -0.000064| | -0.000283 -0.000064 0.997331|Proposed new scale matrix
| 0.023731 -0.000007 0.006055| | -0.000007 0.024085 0.000002| | 0.000004 0.000000 0.014279|With corresponding cell
A = 42.142 B = 41.519 C = 72.281 Alpha= 90.012 Beta= 104.330 Gamma= 89.966
The CRYST1 cell dimensions
A = 42.257 B = 41.586 C = 72.466 Alpha= 90.000 Beta= 104.300 Gamma= 90.000
(Under-)estimated Z-score: 5.139
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.
123 LYS ( 127-) A -O -C N 111.14 -7.4 123 LYS ( 127-) A -CA -C N 127.47 5.6
11 GLU ( 14-) A 29 ASP ( 32-) A 38 ASP ( 41-) A 69 ASP ( 72-) A 82 ASP ( 85-) A 98 ASP ( 101-) A 107 ASP ( 110-) A 135 ASP ( 139-) A 176 ASP ( 180-) A 183 GLU ( 187-) A 186 ASP ( 190-) A 210 GLU ( 214-) A 217 GLU ( 221-) A 230 GLU ( 234-) A 234 GLU ( 238-) A 239 ASP ( 243-) A
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.
55 ARG ( 58-) A -2.7 163 ILE ( 167-) A -2.2 52 THR ( 55-) A -2.2 159 VAL ( 163-) A -2.2 172 PHE ( 176-) A -2.2 147 GLY ( 151-) A -2.1 89 GLN ( 92-) A -2.0 76 LEU ( 79-) 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.
26 SER ( 29-) A PRO omega poor 62 ALA ( 65-) A Poor phi/psi 72 ASP ( 75-) A Poor phi/psi 73 LYS ( 76-) A Poor phi/psi 89 GLN ( 92-) A omega poor 108 LYS ( 111-) A Poor phi/psi 174 ASN ( 178-) A Poor phi/psi 187 TYR ( 191-) A omega poor 193 SER ( 197-) A omega poor 197 PRO ( 201-) A PRO omega poor 199 LEU ( 203-) A Poor phi/psi 203 VAL ( 207-) A omega poor 211 PRO ( 215-) A omega poor 249 ASN ( 253-) A Poor phi/psi, omega poor chi-1/chi-2 correlation Z-score : -1.955
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 TYR ( 7-) A 0 7 HIS ( 10-) A 0 12 HIS ( 15-) A 0 13 TRP ( 16-) A 0 16 ASP ( 19-) A 0 17 PHE ( 20-) A 0 21 LYS ( 24-) A 0 24 ARG ( 27-) A 0 25 GLN ( 28-) A 0 26 SER ( 29-) A 0 35 ALA ( 38-) A 0 47 SER ( 50-) A 0 51 ALA ( 54-) A 0 55 ARG ( 58-) A 0 59 ASN ( 62-) A 0 61 HIS ( 64-) A 0 62 ALA ( 65-) A 0 69 ASP ( 72-) A 0 70 SER ( 73-) A 0 72 ASP ( 75-) A 0 74 ALA ( 77-) A 0 77 LYS ( 80-) A 0 80 PRO ( 83-) A 0 88 ILE ( 91-) A 0 89 GLN ( 92-) A 0And so on for a total of 113 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!
3 GLY ( 6-) A 1.50 21
243 PRO ( 247-) A 0.15 LOW
18 PRO ( 21-) A -114.6 envelop C-gamma (-108 degrees) 211 PRO ( 215-) A 41.9 envelop C-delta (36 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.
55 ARG ( 58-) A CD <-> 66 GLU ( 69-) A OE1 0.25 2.55 INTRA BL 72 ASP ( 75-) A OD1 <-> 86 ARG ( 89-) A NE 0.19 2.51 INTRA 109 LYS ( 112-) A NZ <-> 260 HOH ( 386 ) A O 0.18 2.52 INTRA BL 229 GLY ( 233-) A N <-> 232 GLU ( 236-) A OE1 0.15 2.55 INTRA 98 ASP ( 101-) A OD1 <-> 223 ARG ( 227-) A NH2 0.14 2.56 INTRA BL 260 HOH ( 436 ) A O <-> 260 HOH ( 437 ) A O 0.10 2.10 INTRA BL 55 ARG ( 58-) A CD <-> 66 GLU ( 69-) A CD 0.10 3.10 INTRA BL 44 LEU ( 47-) A N <-> 260 HOH ( 343 ) A O 0.10 2.60 INTRA BL 176 ASP ( 180-) A OD2 <-> 178 ARG ( 182-) A NH2 0.08 2.62 INTRA BL 48 TYR ( 51-) A OH <-> 119 HIS ( 122-) A NE2 0.08 2.62 INTRA BL 184 SER ( 188-) A N <-> 210 GLU ( 214-) A OE1 0.07 2.63 INTRA BL 12 HIS ( 15-) A ND1 <-> 15 LYS ( 18-) A NZ 0.07 2.93 INTRA BL 110 LYS ( 113-) A NZ <-> 260 HOH ( 339 ) A O 0.06 2.64 INTRA BL 115 LEU ( 118-) A N <-> 142 ILE ( 146-) A O 0.06 2.64 INTRA BL 104 HIS ( 107-) A ND1 <-> 114 GLU ( 117-) A OE2 0.06 2.64 INTRA BL 141 GLY ( 145-) A N <-> 206 ILE ( 210-) A O 0.04 2.66 INTRA BL 100 GLN ( 103-) A NE2 <-> 239 ASP ( 243-) A OD1 0.04 2.66 INTRA BL 9 GLY ( 12-) A O <-> 12 HIS ( 15-) A N 0.03 2.67 INTRA BL 116 HIS ( 119-) A ND1 <-> 259 2C7 ( 300-) A NAV 0.02 2.98 INTRA 61 HIS ( 64-) A O <-> 240 ASN ( 244-) A ND2 0.02 2.68 INTRA BL 104 HIS ( 107-) A NE2 <-> 190 TYR ( 194-) A OH 0.02 2.68 INTRA BL 69 ASP ( 72-) A OD2 <-> 120 TRP ( 123-) A NE1 0.01 2.69 INTRA BL
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.
7 HIS ( 10-) A -5.90 132 GLN ( 136-) A -5.15
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
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.
260 HOH ( 441 ) A O Metal-coordinating Histidine residue 91 fixed to 1 Metal-coordinating Histidine residue 93 fixed to 1 Metal-coordinating Histidine residue 116 fixed to 1
133 GLN ( 137-) A 174 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.
28 VAL ( 31-) A N 71 GLN ( 74-) A N 97 LEU ( 100-) A N 196 THR ( 200-) A N 200 LEU ( 204-) A N 226 ASN ( 230-) A ND2 240 ASN ( 244-) A ND2 241 TRP ( 245-) A N 256 PHE ( 260-) A N Only metal coordination for 91 HIS ( 94-) A NE2 Only metal coordination for 93 HIS ( 96-) A NE2 Only metal coordination for 116 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.
33 HIS ( 36-) A ND1
11 GLU ( 14-) A H-bonding suggests Gln 29 ASP ( 32-) A H-bonding suggests Asn 158 ASP ( 162-) A H-bonding suggests Asn; but Alt-Rotamer 232 GLU ( 236-) A H-bonding suggests Gln; 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 : -0.132 2nd generation packing quality : 0.675 Ramachandran plot appearance : -1.384 chi-1/chi-2 rotamer normality : -1.955 Backbone conformation : -0.880
Bond lengths : 0.425 (tight) Bond angles : 0.673 Omega angle restraints : 1.108 Side chain planarity : 0.439 (tight) Improper dihedral distribution : 0.614 Inside/Outside distribution : 0.955
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 : 1.90
Structure Z-scores, positive is better than average:
1st generation packing quality : 0.3 2nd generation packing quality : 0.1 Ramachandran plot appearance : -1.2 chi-1/chi-2 rotamer normality : -1.2 Backbone conformation : -1.3
Bond lengths : 0.425 (tight) Bond angles : 0.673 Omega angle restraints : 1.108 Side chain planarity : 0.439 (tight) Improper dihedral distribution : 0.614 Inside/Outside distribution : 0.955 ==============
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.