X-LIGAND: an application for the automated addition of flexible ligands into electron density

Acta Crystallogr D Biol Crystallogr. 2001 May;57(Pt 5):696-705. doi: 10.1107/s0907444901003894. Epub 2001 Apr 24.


With the advent of drug-design experiments where the interaction between a protein and a ligand is determined using X-ray crystallography, the use of automated methods for modelling the ligand into electron density represents a powerful tool. Once the protein structure has been determined by crystallography it is normal that subsequent ligand-complex structures are isomorphous, or nearly so, with the original structure and it is necessary only to determine the fit of ligand to any unsatisfied electron density. The X-LIGAND application was designed with this protocol in mind and provides a tool that searches for unsatisfied electron density and then fits flexible ligands to this within minutes without user intervention.

MeSH terms

  • Automation
  • Crystallography, X-Ray / methods*
  • Electrons
  • Ligands


  • Ligands