Protein Databank in Europe File retrieval for the Likely Quaternary Structure or MacroMolecular Assembly

The PQS service will not be incremented with new data from August 2009 and the service will be discontinued at some future date.

When examining a macromolecular structure, one is most interested in the structure that is likely to be biologically active.  However, the traditional PDB file of a structure determined by X-ray crystallography normally contains only the contents of the unit cell.  This may represent only part of the biologically relevant structure, or multiple copies of the structure.  The Quaternary Structure File Server (PQS) provides access to probable quaternary structures for macromolecules solved by X-ray crystallography.

For more details about how the quaternary structures are generated see the PQS documentation or the article `PQS: a protein quaternary structure file server`, Henrick and Thornton,  Trends Biochem Sci. 23 (9):358-61 (1998).

The generation of quaternary structures is part of the PDB clean-up at  EBI.  The quaternary structure represetations form the core of the new EBI-PDBe database of macromolecular structure.

see also