Crystallographic Information Framework

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Index

Macromolecular dictionary (mmCIF) version 2.0.09

Category STRUCT_BIOL

Name:
'struct_biol'

Description:

   Data items in the STRUCT_BIOL category record details about
   the structural elements that form each structure of biological
   significance.

   A given crystal structure may contain many different biological
   structures. A given structural component in the asymmetric
   unit may be part of more than one biological unit. A given
   biological structure may involve crystallographic symmetry.

   For instance, in a structure of a lysozyme-FAB structure, the
   light- and heavy-chain components of the FAB could be one
   biological unit, while the two chains of the FAB and the lysozyme
   could constitute a second biological unit.

Example:

Example 1 - based on PDB entry 5HVP and laboratory records for the structure corresponding to PDB entry 5HVP. 
 
    loop_
    _struct_biol.id
    _struct_biol.details
      1
    ; significant deviations from twofold symmetry exist in this
      dimeric enzyme
    ;
      2
    ; The drug binds to this enzyme in two roughly twofold
      symmetric modes. Hence this biological unit (2) is roughly
      twofold symmetric to biological unit (3). Disorder in the
      protein chain indicated with alternative ID 1 should be
      used with this biological unit.
    ;
      3
    ; The drug binds to this enzyme in two roughly twofold
      symmetric modes. Hence this biological unit (3) is roughly
      twofold symmetric to biological unit (2). Disorder in the
      protein chain indicated with alternative ID 2 should be
      used with this biological unit.
    ;


Category groups:
    inclusive_group
    struct_group
Category key:
    _struct_biol.id

Mandatory category: no


International Tables for Crystallography

Volume G: Definition and exchange of crystallographic data

First online edition (2006)

Edited by S. R. Hall and B. McMahon

An essential guide and reference to CIF for programmers, data managers handling crystal-structure information and practising crystallographers.