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:
Crystal temperature (K) :293.000
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: Arginine nomenclature problem
The arginine residues listed in the table below have their N-H-1 and N-H-2
56 ARG ( 58-) A
5 TYR ( 7-) A
12 GLU ( 14-) A 24 GLU ( 26-) A 236 GLU ( 239-) A
RMS Z-score for bond lengths: 0.228
RMS-deviation in bond distances: 0.005
Warning: Low bond angle variability
Bond angles were found to deviate less than normal from the 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 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 angles: 0.581
RMS-deviation in bond angles: 1.201
Error: Nomenclature error(s)
Checking for a hand-check. WHAT IF has over the course of this session
already corrected the handedness of atoms in several residues. These were
administrative corrections. These residues are listed here.
12 GLU ( 14-) A 24 GLU ( 26-) A 56 ARG ( 58-) A 236 GLU ( 239-) 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.
199 PRO ( 202-) A -3.0 173 PHE ( 176-) A -2.6 81 PRO ( 83-) A -2.2 148 GLY ( 151-) 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.
27 SER ( 29-) A PRO omega poor 62 TRP ( 64-) A omega poor 63 ALA ( 65-) A Poor phi/psi 65 ASN ( 67-) A omega poor 93 PHE ( 95-) A omega poor 109 LYS ( 111-) A Poor phi/psi 138 LEU ( 141-) A omega poor 175 ASN ( 178-) A Poor phi/psi 194 SER ( 197-) A omega poor 198 PRO ( 201-) A PRO omega poor 200 LEU ( 203-) A Poor phi/psi 204 VAL ( 207-) A omega poor 235 GLU ( 238-) A omega poor 249 LYS ( 252-) A Poor phi/psi 250 ASN ( 253-) A Poor phi/psi 257 PHE ( 260-) A omega poor chi-1/chi-2 correlation Z-score : -1.085
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 TRP ( 5-) A 0 5 TYR ( 7-) A 0 8 HIS ( 10-) A 0 17 ASP ( 19-) A 0 18 PHE ( 20-) A 0 22 LYS ( 24-) A 0 25 ARG ( 27-) A 0 26 GLN ( 28-) A 0 27 SER ( 29-) A 0 36 ALA ( 38-) A 0 43 LYS ( 45-) A 0 48 SER ( 50-) A 0 51 GLN ( 53-) A 0 52 ALA ( 54-) A 0 55 LEU ( 57-) A 0 60 ASN ( 62-) A 0 62 TRP ( 64-) A 0 63 ALA ( 65-) A 0 70 ASP ( 72-) A 0 71 SER ( 73-) A 0 73 ASP ( 75-) A 0 74 LYS ( 76-) A 0 75 ALA ( 77-) A 0 78 LYS ( 80-) A 0 81 PRO ( 83-) A 0And so on for a total of 112 lines.
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.
76 VAL ( 78-) A CG2 <-> 78 LYS ( 80-) A NZ 0.25 2.85 INTRA 69 ASP ( 71-) A OD2 <-> 74 LYS ( 76-) A NZ 0.21 2.49 INTRA 3 TRP ( 5-) A O <-> 62 TRP ( 64-) A CZ3 0.20 2.60 INTRA 117 HIS ( 119-) A O <-> 260 HOH ( 449 ) A O 0.17 2.23 INTRA 115 GLU ( 117-) A OE2 <-> 117 HIS ( 119-) A NE2 0.16 2.54 INTRA BL 217 SER ( 220-) A O <-> 221 LEU ( 224-) A CD2 0.16 2.64 INTRA 73 ASP ( 75-) A CG <-> 87 ARG ( 89-) A NH2 0.16 2.94 INTRA 230 GLY ( 233-) A N <-> 233 GLU ( 236-) A OE1 0.14 2.56 INTRA 56 ARG ( 58-) A NH2 <-> 67 GLU ( 69-) A OE2 0.12 2.58 INTRA 78 LYS ( 80-) A NZ <-> 85 THR ( 87-) A CG2 0.12 2.98 INTRA 124 LYS ( 127-) A NZ <-> 260 HOH ( 345 ) A O 0.11 2.59 INTRA 158 VAL ( 161-) A CG1 <-> 222 LYS ( 225-) A CD 0.10 3.10 INTRA 34 HIS ( 36-) A ND1 <-> 260 HOH ( 373 ) A O 0.10 2.60 INTRA 3 TRP ( 5-) A CD2 <-> 198 PRO ( 201-) A CG 0.09 3.11 INTRA 7 LYS ( 9-) A CE <-> 8 HIS ( 10-) A NE2 0.08 3.02 INTRA 193 GLY ( 196-) A N <-> 204 VAL ( 207-) A O 0.08 2.62 INTRA BL 119 VAL ( 121-) A CG2 <-> 260 HOH ( 449 ) A O 0.08 2.72 INTRA 56 ARG ( 58-) A CG <-> 57 ILE ( 59-) A N 0.07 2.93 INTRA 105 HIS ( 107-) A NE2 <-> 191 TYR ( 194-) A OH 0.07 2.63 INTRA BL 205 THR ( 208-) A OG1 <-> 260 HOH ( 391 ) A O 0.06 2.34 INTRA 70 ASP ( 72-) A OD2 <-> 121 TRP ( 123-) A NE1 0.06 2.64 INTRA 45 LEU ( 47-) A CD2 <-> 46 SER ( 48-) A N 0.06 2.94 INTRA 13 HIS ( 15-) A ND1 <-> 16 LYS ( 18-) A NZ 0.04 2.96 INTRA BL 25 ARG ( 27-) A CG <-> 202 GLU ( 205-) A CD 0.04 3.16 INTRA BL 175 ASN ( 178-) A N <-> 260 HOH ( 338 ) A O 0.04 2.66 INTRA 49 TYR ( 51-) A OH <-> 120 HIS ( 122-) A NE2 0.03 2.67 INTRA BL 196 THR ( 199-) A OG1 <-> 260 HOH ( 297 ) A O 0.03 2.37 INTRA BL 134 GLN ( 137-) A O <-> 203 CYS ( 206-) A CB 0.02 2.78 INTRA BL 249 LYS ( 252-) A CB <-> 250 ASN ( 253-) A N 0.02 2.68 INTRA BL 101 GLN ( 103-) A NE2 <-> 240 ASP ( 243-) A OD1 0.02 2.68 INTRA BL 56 ARG ( 58-) A O <-> 67 GLU ( 69-) A N 0.02 2.68 INTRA BL 97 SER ( 99-) A N <-> 98 LEU ( 100-) A N 0.01 2.59 INTRA BL 20 ILE ( 22-) A O <-> 23 GLY ( 25-) A N 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.
8 HIS ( 10-) A -6.32 2 HIS ( 4-) A -5.74 98 LEU ( 100-) A -5.30
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.
16 LYS ( 18-) A -2.59
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.
51 GLN ( 53-) A 175 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.
8 HIS ( 10-) A NE2 29 VAL ( 31-) A N 72 GLN ( 74-) A N 98 LEU ( 100-) A N 162 ASP ( 165-) A N 174 THR ( 177-) A OG1 179 ARG ( 182-) A NH2 197 THR ( 200-) A N 201 LEU ( 204-) A N 227 ASN ( 230-) A ND2 241 ASN ( 244-) A ND2 242 TRP ( 245-) A N 257 PHE ( 260-) A N Only metal coordination for 94 HIS ( 96-) A NE2 Only metal coordination for 117 HIS ( 119-) A ND1
159 ASP ( 162-) 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 : -0.133 2nd generation packing quality : 0.615 Ramachandran plot appearance : -1.647 chi-1/chi-2 rotamer normality : -1.085 Backbone conformation : -0.889
Bond lengths : 0.228 (tight) Bond angles : 0.581 (tight) Omega angle restraints : 0.873 Side chain planarity : 0.207 (tight) Improper dihedral distribution : 0.576 B-factor distribution : 0.649 Inside/Outside distribution : 0.951
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 : 1.80
Structure Z-scores, positive is better than average:
1st generation packing quality : 0.2 2nd generation packing quality : -0.1 Ramachandran plot appearance : -1.6 chi-1/chi-2 rotamer normality : -0.8 Backbone conformation : -1.2
Bond lengths : 0.228 (tight) Bond angles : 0.581 (tight) Omega angle restraints : 0.873 Side chain planarity : 0.207 (tight) Improper dihedral distribution : 0.576 B-factor distribution : 0.649 Inside/Outside distribution : 0.951 ==============
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.