WHAT IF Check report

This file was created 2017-09-10 from WHAT_CHECK output by a conversion script. If you are new to WHAT_CHECK, please study the pdbreport pages. There also exists a legend to the output.

Verification log for /srv/data/pdb/flat/pdb1y4f.ent

Checks that need to be done early-on in validation

Note: Introduction

WHAT CHECK needs to read a PDB file before it can check it. It does a series of checks upon reading the file. The results of these checks are reported in this section (section 2.1). The rest of the report will be more systematic in that section 2.2 reports on administrative problems. Section 2.3 gives descriptive output that is not directly validating things but more telling you how WHAT CHECK interpreted the input file. Section 2.4 looks at B-factors, occupancies, and the presence/absence of (spurious) atoms. Section 2.5 deals with nomenclature problems. Section 2.6 deals with geometric problems like bond lengths and bond angles. Section 2.7 deals with torsion angle issues. Section 2.8 looks at atomic clashes. Section 2.9 deals with packing, accessibility, etc, issues. Section 2.10 deals with hydrogen bonds, ion packing, and other things that can be summarized under the common name charge-charge interactions. Section 2.11 gives a summary of whole report and tells you (if applicable) which symmetry matrices were used. Section 2.12 tells the crystallographer which are the things most in need of manual correction. And the last section, section 2.13, lists all residues sorted by their need for visual inspection in light of the electron density.

Note: Header records from PDB file

Header records from PDB file.

HEADER    TRANSPORT PROTEIN                       30-NOV-04   1Y4F
T-TO-T(HIGH) QUATERNARY TRANSITIONS IN HUMAN HEMOGLOBIN:
 BETAW37A DEOXY LOW-SALT (10 TEST SETS)
HEMOGLOBIN MUTANT, GLOBIN, TRANSPORT PROTEIN
JRNL        J.S.KAVANAUGH,P.H.ROGERS,A.ARNONE
JRNL        CRYSTALLOGRAPHIC EVIDENCE FOR A NEW ENSEMBLE OF
JRNL        LIGAND-INDUCED ALLOSTERIC TRANSITIONS IN
JRNL        HEMOGLOBIN: THE T-TO-T(HIGH) QUATERNARY
JRNL        TRANSITIONS.
JRNL        REF    BIOCHEMISTRY                  V.  44  6101 2005
JRNL        REFN                   ISSN 0006-2960
JRNL        PMID   15835899
JRNL        DOI    10.1021/BI047813A

Note: Non crystallographic symmetry RMS plot

The plot shows the RMS differences between two similar chains on a residue- by-residue basis. Individual "spikes" can be indicative of interesting or wrong residues. If all residues show a high RMS value, the structure could be incorrectly refined.

Chain identifiers of the two chains: A and C

All-atom RMS fit for the two chains : 0.509
CA-only RMS fit for the two chains : 0.184

Note: Non crystallographic symmetry backbone difference plot

The plot shows the differences in backbone torsion angles between two similar chains on a residue-by-residue basis. Individual "spikes" can be indicative of interesting or wrong residues. If all residues show high differences, the structure could be incorrectly refined.

Chain identifiers of the two chains: A and C

Note: Non crystallographic symmetry RMS plot

The plot shows the RMS differences between two similar chains on a residue- by-residue basis. Individual "spikes" can be indicative of interesting or wrong residues. If all residues show a high RMS value, the structure could be incorrectly refined.

Chain identifiers of the two chains: B and D

All-atom RMS fit for the two chains : 0.639
CA-only RMS fit for the two chains : 0.258

Note: Non crystallographic symmetry backbone difference plot

The plot shows the differences in backbone torsion angles between two similar chains on a residue-by-residue basis. Individual "spikes" can be indicative of interesting or wrong residues. If all residues show high differences, the structure could be incorrectly refined.

Chain identifiers of the two chains: B and D

Note: Counting molecules and matrices

The parameter Z as given on the CRYST card represents the molecular multiplicity in the crystallographic cell. Z equals the number of matrices of the space group multiplied by the number of NCS relations. These numbers seem to be consistent.

Space group as read from CRYST card: P 21 21 2
Number of matrices in space group: 4
Highest polymer chain multiplicity in structure: 2
Highest polymer chain multiplicity according to SEQRES: 2
No explicit MTRIX NCS matrices found in the input file
Value of Z as found on the CRYST1 card: 8
Z, spacegroup, and NCS seem to agree administratively

Note: Matthews coefficient OK

The Matthews coefficient [REF] is defined as the density of the protein structure in cubic Angstroms per Dalton. Normal values are between 1.5 (tightly packed, little room for solvent) and 4.0 (loosely packed, much space for solvent). Some very loosely packed structures can get values a bit higher than that.

Molecular weight of all polymer chains: 61813.430
Volume of the Unit Cell V= 635630.188
Space group multiplicity: 4
No NCS symmetry matrices (MTRIX records) found in PDB file
Matthews coefficient for observed atoms and Z: Vm= 2.571
One BIOMT matrix observed in the PDB file, but that is the unitary one
Matthews coefficient read from REMARK 280 Vm= 2.570
Vm by authors and this calculated Vm agree remarkably well

Note: All atoms are sufficiently far away from symmetry axes

None of the atoms in the structure is closer than 0.77 Angstrom to a proper symmetry axis.

Note: Chain identifiers OK

WHAT CHECK has not detected any serious chain identifier problems. But be aware that WHAT CHECK doesn't care about the chain identifiers of waters.

Administrative problems that can generate validation failures

Note: No strange inter-chain connections detected

No covalent bonds have been detected between molecules with non-identical chain identifiers.

Note: No duplicate atom names in ligands

All atom names in ligands (if any) seem adequately unique.

Note: In all cases the primary alternate atom was used

WHAT CHECK saw no need to make any alternate atom corrections (which means they either are all correct, or there are none).

Note: No residues detected inside ligands

Either this structure does not contain ligands with amino acid groups inside it, or their naming is proper (enough).

Warning: Groups attached to potentially hydrogen-bonding atoms

Residues were observed with groups attached to (or very near to) atoms that potentially can form hydrogen bonds. WHAT CHECK is not very good at dealing with such exceptional cases (Mainly because it's author is not...). So be warned that the hydrogen-bonding related analyses of these residues might be in error.

For example, an aspartic acid can be protonated on one of its delta oxygens. This is possible because the one delta oxygen 'helps' the other one holding that proton. However, if a delta oxygen has a group bound to it, then it can no longer 'help' the other delta oxygen bind the proton. However, both delta oxygens, in principle, can still be hydrogen bond acceptors. Such problems can occur in the amino acids Asp, Glu, and His. I have opted, for now to simply allow no hydrogen bonds at all for any atom in any side chain that somewhere has a 'funny' group attached to it. I know this is wrong, but there are only 12 hours in a day.

   87 HIS  (  87-) A  -    NE2 bound to   579 HEM  ( 142-) A  -   FE
  233 HIS  (  92-) B  -    NE2 bound to   580 HEM  ( 147-) B  -   FE
  374 HIS  (  87-) C  -    NE2 bound to   581 HEM  ( 142-) C  -   FE
  520 HIS  (  92-) D  -    NE2 bound to   582 HEM  ( 147-) D  -   FE

Note: No probable side chain atoms with zero occupancy detected.

Either there are no side chain atoms with zero occupancy, or the side chain atoms with zero occupancy were not present in the input PDB file (in which case they are listed as missing atoms), or their positions are sufficiently improbable to warrant a zero occupancy.

Note: No probable backbone atoms with zero occupancy detected.

Either there are no backbone atoms with zero occupancy, or the backbone atoms with zero occupancy were left out of the input PDB file (in which case they are listed as missing atoms), or their positions are sufficiently improbable to warrant a zero occupancy.

Note: All residues have a complete backbone.

No residues have missing backbone atoms.

Note: No C-alpha only residues

There are no residues that consist of only an alpha carbon atom.

Non-validating, descriptive output paragraph

Note: Content of the PDB file as interpreted by WHAT CHECK

Content of the PDB file as interpreted by WHAT CHECK. WHAT CHECK has read your PDB file, and stored it internally in what is called 'the soup'. The content of this soup is listed here. An extensive explanation of all frequently used WHAT CHECK output formats can be found at swift.cmbi.ru.nl. Look under output formats. A course on reading this 'Molecules' table is part of the WHAT CHECK website.

     1     1 (    1)   141 (  141) A Protein             /srv/data/pdb/fla...
     2   142 (    1)   287 (  146) B Protein             /srv/data/pdb/fla...
     3   288 (    1)   428 (  141) C Protein             /srv/data/pdb/fla...
     4   429 (    1)   574 (  146) D Protein             /srv/data/pdb/fla...
     5   575 (  141)   575 (  141) A R O2 <-   141       /srv/data/pdb/fla...
     6   576 (  146)   576 (  146) B H O2 <-   287       /srv/data/pdb/fla...
     7   577 (  141)   577 (  141) C R O2 <-   428       /srv/data/pdb/fla...
     8   578 (  146)   578 (  146) D H O2 <-   574       /srv/data/pdb/fla...
     9   579 (  142)   579 (  142) A HEM  <-             /srv/data/pdb/fla...
    10   580 (  147)   580 (  147) B HEM  <-             /srv/data/pdb/fla...
    11   581 (  142)   581 (  142) C HEM  <-             /srv/data/pdb/fla...
    12   582 (  147)   582 (  147) D HEM  <-             /srv/data/pdb/fla...
    13   583 ( HOH )   583 ( HOH ) A water   (   60)     /srv/data/pdb/fla...
    14   584 ( HOH )   584 ( HOH ) B water   (   41)     /srv/data/pdb/fla...
    15   585 ( HOH )   585 ( HOH ) C water   (   44)     /srv/data/pdb/fla...
    16   586 ( HOH )   586 ( HOH ) D water   (   30)     /srv/data/pdb/fla...
MODELs skipped upon reading PDB file: 0
X-ray structure. No MODELs found
The total number of amino acids found is 574.
No nucleic acids observed in input file
No sugars recognized in input file
Number of water molecules: 175
Residue numbers increase monotonously OK

Some numbers...

Note: Ramachandran plot

Chain identifier: A

Note: Ramachandran plot

Chain identifier: B

Note: Ramachandran plot

Chain identifier: C

Note: Ramachandran plot

Chain identifier: D

Note: Secondary structure

Secondary structure assignment

Coordinate problems, unexpected atoms, B-factor and occupancy checks

Note: No rounded coordinates detected

Note: No artificial side chains detected

Note: No missing atoms detected in residues

Note: All B-factors fall in the range 0.0 - 100.0

Note: C-terminus capping




Note: Weights administratively correct

Note: Normal distribution of occupancy values



Note: All occupancies seem to add up to 0.0 - 1.0.

Warning: What type of B-factor?



Note: Number of buried atoms with low B-factor is OK

Note: B-factor distribution normal



Note: B-factor plot

Chain identifier: A

Note: B-factor plot

Chain identifier: B

Note: B-factor plot

Chain identifier: C

Note: B-factor plot

Chain identifier: D

Nomenclature related problems

Note: Introduction to the nomenclature section.

Note: Valine nomenclature OK

Note: Threonine nomenclature OK

Note: Isoleucine nomenclature OK

Note: Leucine nomenclature OK

Note: Arginine nomenclature OK

Note: Tyrosine torsion conventions OK

Warning: Phenylalanine convention problem


Note: Aspartic acid torsion conventions OK

Warning: Glutamic acid convention problem


Note: Phosphate group names OK in DNA/RNA

Note: Heavy atom naming OK

Note: No decreasing residue numbers

Geometric checks

Note: All bond lengths OK

Note: Normal bond length variability


Note: No bond length directionality

Warning: Unusual bond angles


Note: Normal bond angle variability


Error: Nomenclature error(s)


Note: Chirality OK

Note: Improper dihedral angle distribution OK

Note: Tau angles OK

Note: Normal tau angle deviations

Note: Side chain planarity OK

Note: Atoms connected to aromatic rings OK

Torsion-related checks

Note: Ramachandran Z-score OK

Note: Ramachandran check

Warning: Torsion angle evaluation shows unusual residues


Warning: Backbone evaluation reveals unusual conformations


Error: Chi-1/chi-2 rotamer problems


Warning: chi-1/chi-2 angle correlation Z-score low

Warning: Unusual rotamers


Warning: Unusual backbone conformations


Note: Backbone conformation Z-score OK

Warning: Omega angles too tightly restrained

Warning: Unusual PRO puckering amplitudes


Note: PRO puckering phases OK

Note: Backbone oxygen evaluation OK

Note: Peptide bond conformations

Bump checks

Error: Abnormally short interatomic distances


Note: Some notes regarding these bumps









Packing, accessibility and threading

Note: Inside/outside distribution check

Note: Inside/Outside residue distribution normal

Note: Inside/Outside RMS Z-score plot

Chain identifier: A

Note: Inside/Outside RMS Z-score plot

Chain identifier: B

Note: Inside/Outside RMS Z-score plot

Chain identifier: C

Note: Inside/Outside RMS Z-score plot

Chain identifier: D

Warning: Abnormal packing environment for some residues


Warning: Abnormal packing environment for sequential residues


Note: Structural average packing environment OK

Note: Quality value plot

Chain identifier: A

Note: Quality value plot

Chain identifier: B

Note: Quality value plot

Chain identifier: C

Note: Quality value plot

Chain identifier: D

Note: Second generation packing environment OK

Note: No series of residues with abnormal new packing environment

Note: Second generation quality Z-score plot

Chain identifier: A

Note: Second generation quality Z-score plot

Chain identifier: B

Note: Second generation quality Z-score plot

Chain identifier: C

Note: Second generation quality Z-score plot

Chain identifier: D

Water, ion, and hydrogen bond related checks

Note: Crystallisation conditions from REMARK 280


Error: Water clusters without contacts with non-water atoms


Note: No waters need moving

Error: Water molecules without hydrogen bonds


Error: His, Asn, Gln side chain flips


Note: Histidine type assignments


Warning: Buried unsatisfied hydrogen bond donors


Warning: Buried unsatisfied hydrogen bond acceptors


Note: Some notes regarding these donors and acceptors


















Note: Content of the PDB file as interpreted by WHAT CHECK


Final summary

Note: Summary report







Suggestions for the refinement process

Note: Introduction to refinement recommendations

Note: No crippling problems detected

Error: Bumps in your structure

Note: His, Asn, Gln side chain flips.

Note: Free floating waters

Residues in need of attention

Warning: Troublesome residues