Nov 18, 2014
from 11:00 AM to 12:00 PM
|Contact Name||Amanda Chang|
Open to the public
|Add event to calendar||
Joint UNC Program in Molecular & Cellular Biophysics and UNC Biochemistry & Biophysics Seminar
"Long lost relatives: The expanding PUF protein family"
Traci Hall, PhD
Structural Biology Laboratory/Macromolecular Structure Group
National Institute of Health
Research Triangle Park, NC
Bio: Traci M.T. Hall, Ph.D. is a tenured Senior Investigator leading the Macromolecular Structure Group and Acting Chief of the Laboratory of Structural Biology.ˇ She earned her B.S. in biochemistry from the University of California, Los Angeles, and her Ph.D. in pharmacology and molecular sciences from the Johns Hopkins University School of Medicine.ˇ She was an American Association for the Advancement of Science Diplomacy Fellow with the U.S. Agency for International Development and a postdoctoral fellow with Daniel J. Leahy at Johns Hopkins before joining the NIEHS in 1998.
Abstract: RNA regulation occurs at many levels including processing to mature forms, subcellular localization, and translation. RNA-binding proteins are crucial to direct and regulate these processes. PUF proteins bind sequence specifically to mRNA targets using a single-stranded RNA-binding domain comprising eight a-helical repeats (PUM repeats). Our lab’s previous structural studies revealed characteristic curved structures and sequence specificity unique to these classical PUF proteins. In fact, the sequence specificity of the classical PUF protein, human Pumilio1, can be designed by site-directed mutagenesis. PUM repeats have now been identified in proteins that function in pre-rRNA processing, including human Puf-A and yeast Puf6. This is a role not previously ascribed to PUF proteins. In my talk, I will show new crystal structures of human Puf-A protein that reveal a novel class of nucleic acid-binding proteins with eleven PUM repeats arranged in an “L”-like shape. In contrast to classical PUF proteins, Puf-A recognizes double-stranded RNA or DNA without sequence specificity. We demonstrate that basic surfaces of the yeast homologue, Puf6, are important for RNA-binding, pre-rRNA processing and ASH1 mRNA localization. Thus, PUM repeats can be assembled into alternative folds that bind to structured nucleic acids in addition to forming canonical eight-repeat crescent-shaped RNA-binding domains found in classical PUF proteins.
Host: Saskia Neher