Protein Data Bank Japan (PDBj) is a specialized database that provides access to three-dimensional structures of biological macromolecules, such as proteins and nucleic acids. It is part of the global Protein Data Bank (PDB) network, which collects and shares structural data to support scientific research and education. PDBj offers various tools and resources for researchers, including visualization software and search functionalities. It aims to facilitate the understanding of molecular structures and their functions, contributing to advancements in fields like biochemistry, molecular biology, and drug discovery.