W0018

Crystal Structure of Ribonuclease P Protein Reveals Novel RNA Binding Motifs. Travis Stams¹, S. Niranjanakumari², Carol A. Fierke², and David W. Christianson¹, ¹Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, ²Department of Biochemistry, Duke University Medical Center, Durham, NC 27710

The x-ray crystal structure of ribonuclease P protein from B. subtilis has been determined at 2.6 Å resolution. Ribonuclease P (RNase P) is a metal-dependent ribozyme that requires this protein subunit for catalytic activity in vivo. The protein subunit adopts the fold of an a-b sandwich in which three RNA binding motifs are found. Implications for RNase P function will be presented, and topological similarities with other proteins of translational regulation indicate ancient origins of the a-b fold in the evolution of the protein world from the RNA world.