All biological phenomena are caused by the interactions of proteins, nucleic acids, lipids, and other biopolymers, which change their shapes and form networks of intermolecular interactions. Our laboratory aims to elucidate the molecular mechanisms of various biological phenomena from the viewpoints of both biology and physical chemistry at the atomic level by performing “X-ray crystallography,” “single particle analysis by cryo-EM,” “computational molecular dynamics simulation analysis,” and “functional analysis” based on such structural information. We aim to elucidate the molecular mechanisms of various phenomena in living organisms from the viewpoints of both biology and physical chemistry. Currently, we are focusing on the following four biological phenomena: 1. expression of genetic information regulated by functional RNAs (CRISPR-Cas9, RNA silencing, translation of genetic code), 2. trans-membrane transport and sensory reception by membrane proteins, 3. elucidation of signaling mechanism of GPCR and drug discovery, 4. dynamic structural analysis of supramolecular complexes. We have determined the crystal structure of CRISPR-Cas9, which is attracting attention as a genome editing tool (left figure), and elucidated its RNA-dependent DNA cleavage mechanism. We also determined the structure of P4-ATPase, which transports phospholipids by conjugation with ATP hydrolysis, by single-particle analysis using cryo-EM (right figure), and elucidated the mechanism of phospholipid transport as a molecular animation by connecting the structures of each step of the transport cycle. We are also studying the mechanisms of more complex higher-order biological phenomena in animal cells, especially RNA silencing, sensory perception of physical stimuli such as light, temperature, and pressure, the five senses including taste and smell, and cancer metastasis.