Distinguished Lecture Series Guest Speaker: Susan Buchanan
Chief, Structural Biology of Membrane Proteins
National Institute for Diabetes & Digestive & Kidney Diseases
National Institutes of Health
Date & Time: Tuesday, October 16, 2012, 11:00AM
Location: Klaus 1116E
Host: Raquel Lieberman
Abstract: Neisseria are obligate human pathogens causing bacterial meningitis, septicemia, and gonorrhea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are: 1) how human transferrin is specifically targeted, and 2) how the bacteria liberate iron from transferrin at neutral pH. To address them, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Collectively, our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process.
Additional Info: Susan Buchanan is Chief of the Section on Structural Biology of Membrane Proteins in the National Institute for Diabetes & Digestive & Kidney Diseases, at the National Institutes of Health. She received her Ph.D. from the Johann-Wolfgang-Goethe Universität in Frankfurt, Germany in 1990. She completed postdoctoral fellowships at the MRC Laboratory of Molecular Biology, Cambridge, UK, and at UT Southwestern Medical Center, Dallas, before returning to the UK to establish a research group at Birkbeck College, London in 1998. She joined the NIDDK as a tenure track investigator in 2001 and is currently a senior investigator in the Laboratory of Molecular Biology, NIDDK.
