Title: Extraction and Using Geometrical Features from 3-dimensional Images for Protein Structure Prediction Jing He Assistant Professor Department of Computer Science CREST Center for Bioinformatics and Computational Biology New Mexico State University Abstract Protein structure prediction is also known as the protein folding problem that attracts the scientists from many disciplines. Generally, protein structure prediction uses the amino acid sequence information of the protein to build possible conformations and searches for one that has the global minimum energy. However, current structure prediction methods are still far from being mature. We have been investigating the problem of combining the structure prediction methods with geometrical constraints that can be obtained from the low resolution 3-dimensional image of protein density. In this talk, I will present our two approaches to reduce the huge topological search space of the secondary structures. The first approach is built on top of Rosetta, a popular ab initio structure prediction software. The second is through the direct measuring of the energy formed by the secondary structures. For this approach, we have developed a multi-well function based on a Lennard-Jones-like energy function using the statistical data from the Protein Data Bank. For 43 of the 51 proteins tested, the contact energy of the secondary structures in the native topology is within the lowest 5% of that among all the possible topologies. This result demonstrates that it is possible to use the secondary structures, instead of the entire chain of the protein, to eliminate the majority bad topologies of the structure. Bio: Dr. He obtained her B.S. degree in Applied Mathematics from Jilin University, and M.S. degree in Applied Mathematics from Mew Mexico State University. She worked in the area of 3-dimensional reconstruction and analysis of virus structures at Baylor College of Medicine from which she obtained her Ph.D. in Structural and Computational Biology and Molecular Biophysics. Currently she is an Assistant Professor at the Department of Computer Science.