image: This image shows the crystal structure of translocator protein 18 kDa (TSPO) from Rhodobacter sphaeroides with an endogenous ligand, a porphyrin (black), in the central cavity of one monomer of the dimeric structure, represented in a simulated membrane. TSPO is an ancient membrane protein that is found in mitochondria and bacterial ancestors such as Rhodobacter sphaeroides. Below the protein are shown structures of a mitochondrion and Rhodobacter and above are some of TSPO's known ligands, PK11195, porphyrin and cholesterol. High-resolution crystal structures were obtained of wild-type and a mutant corresponding to a human single polymorphism related to anxiety disorders, which shows significant structural alterations and reduced cholesterol binding. This material relates to papers that appeared in the Jan. 30, 2015 issue of Science, published by AAAS. The paper, Fei Li at Michigan State University in East Lansing, MI, and colleagues was titled, "Crystal structures of translocator protein (TSPO) and mutant mimic of a human polymorphism." view more
Credit: [Credit: Fei Li]