Q-BioLiP: Quaternary structure-based protein-ligand interactions

Welcome to Q-BioLiP

Q-BioLiP is an updated version of the original BioLiP database for protein-ligand interactions. One of the major improvements over BioLiP are the protein-ligand interactions are based on quaternary structure rather than single-chain monomer structure. DNA/RNA chains are also paired rather than separated. To predict the ligand-binding site for new structures, Q-SITE can be used. Read more about the Q-BioLiP...

For each structure from PDB (in mmCIF format), the following annotation data are provided in Q-BioLiP:

Receptor information

Ligand information

Assessment of the biological relevance

Ligand-binding residues

Experimental (if available) and predicted binding affinities

Interactive visualization of the protein-ligand interactions

Download of protein-ligand complex structures in mmCIF/PDB format

Statistics (Version 2026-07-03)

total entries: 3,449,130
biological relevant interactions: 1,154,706
nucleic acids ligands: 41,398
peptide ligands: 57,245
ligands binding to multiple chains: 354,399

monomers: 112,678
dimers: 68,994
trimers: 10,605
tetramers: 19,588
others: 27,668

Statistics of receptors involved in the biological relevant interactions

peptides: 57,245
nucleic acids: 41,398
metal ions: 394,679
k-mers: 42,099
other ligands: 619,285

Statistics of nucleic acids in the biological relevant interactions

DNAs: 15,312
RNAs: 23,491
DNA-RNAs: 2,595

Statistics of ligands in the biological relevant interactions

Biologically relevant interactions

The ligands are biologically relevant and interact tightly with the protein structures. This is the core data of Q-BioLiP, containing 1,154,706 entries.

Biologically irrelevant interactions

The structures contain both proteins and ligands, but without biologically relevant interactions. It contains 2,213,738 entries.

Structures with proteins/ligands only

The structures contain proteins/ligands only. It contains 80,686 entries.