Molecular Architecture and Energy Visualization: Advancing Insights into Protein Structure, Interactions, and Activity.

Protein biochemistry continues to progress rapidly through ongoing discoveries, from newly identified proteins to fascinating structural insights into mechanisms. Since proteins are the main machinery of cellular life, the desire to visualize their structure, whether through experimental or computationally obtained methods, has greatly increased. The ability to see proteins in three dimensions has become an essential tool in structural biology, protein design, drug development, and related fields. Among the available tools, PyMOL has become one of the most versatile and easy-to-learn platforms for structure visualization, allowing researchers to closely examine proteins and analyze their structural features. This chapter briefly explains how amino acids influence protein structure, then describes the hierarchical levels of protein organization. It illustrates how tertiary and potential quaternary structures form from energy landscapes that direct proper folding. Key regulatory interactions, such as allostery and metal binding, are highlighted. The chapter concludes by discussing PyMOL features for analyzing pH-dependent charge states, solvent accessibility, and structural or sequence alignments to better understand conformational changes and gain deeper structural insights.