We are interested in  studying 3D structures of proteins and their interactions with other proteins,  nucleic acids, and small molecule ligands, using NMR spectroscopy along with  other techniques in biochemistry and molecular biology, aiming to reveal  protein structure-function relationship and molecular mechanisms for protein  functions, including the roles of anti-tumor gene H-REV-107 family proteins in  cell death, the structural basis of bacterial nucleoid-associated proteins in  transcription regulation, the function of pro-apoptotic protein Bcl-XL in  autophagy, the mechanism of glutaredoxins in iron and oxygen sensing, and  protein folding and structural fluctuations using SARS-CoV main protease as a  model.