Table 1.

Protein structure databases

Database	URL	Description
Therapeutic Target Database (TTD)	https://db.idrblab.org/ttd/	Known potential therapeutic targets, including protein and nucleic acid targets, were collected from the existing literature. However, the 3D structures of many of these targets have not yet been resolved.
Potential Drug-Target Database (PDTD)	http://www.dddc.ac.cn/pdtd/	Similar to TTD, PDTD contains only protein receptors and is a protein receptor with a known 3D structure.
Drug Adverse Reaction Database (DART)	http://bidd.nus.edu.sg/group/drt	This is for protein receptors that have adverse drug reactions
Small Molecule Transcription Factor Database (SM-TF)	http://zoulab.dalton.missouri.edu/SM-TF/	The structures of transcription factors that bind to small molecules are collected from the Protein Data Bank (PDB). The dysfunction of transcription factors is directly related to many diseases and is the target protein of many drugs.
PDBbind (a comprehensive collection of binding affinities for the protein–ligand complexes in the PDB)	WWW.pdbbind.org.cn	All protein–ligand complex structures with experimentally measured binding affinity data in the PDB database were collected. In addition to experimental binding affinity data (Kd, Ki or IC50), the database also provides the cleaned protein 3D structure and corresponding ligand structure.

3D, three-dimensional; IC50, half maximal (50%) inhibitory concentration of a substance.