Protein structure is a field of research that focuses on studying the three-dimensional arrangement of atoms in a protein molecule. Proteins are large biological molecules that play critical roles in various cellular functions, and their structure is closely related to their function. Understanding protein structure is essential for informing drug design, predicting protein function, and elucidating disease mechanisms. Techniques used in protein structure research include X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy. This research area is fundamental to the advancement of biochemistry, biophysics, and molecular biology.