Faculty Candidate Seminar: John Hardin, Investigator, Medical Research Council, Cambridge, UK
University of Massachusetts Boston
Department of Chemistry
Faculty Candidate Seminar
Understanding Large Macromolecular Ribonucleoprotein Particles (RNPs): Assembly, Structure, and Function
Dr. John Hardin
Medical Research Council
Laboratory of Molecular Biology
Structural Studies Division - Nagai Laboratory
Wednesday, March 5, 2014 | 11:00 AM
Chemistry Conference Room (Science S01-0089)
Eukaryotic genes are often interspersed with non‐coding genetic elements called introns. For protein production, the introns must be excised from pre‐mRNA and the coding exon sequences spliced together. This process is carried out by the spliceosome, a multi‐megadalton complex comprised of five small nuclear ribonucleoprotein complexes (snRNPs). Besides being prohibitively large, the spliceosome is compositionally and conformationally dynamic and has deterred attempts at structural characterization for decades. Recent successes in solving the first complete snRNP structure (U1 snRNP) have inspired a further dedication to the effort to understand splicing from a structural perspective. In the first part of my talk, I will present some early results in the ongoing endeavor to characterize the assembly of the U4/U6 di-snRNP with the aim of preparing material suitable for eventual crystallization and structure determination. The second part of my talk will focus on YxiN, a bacterial DEAD‐box helicase homolog of DbpA that aids the maturation of the 50S ribosomal subunit. This helicase is currently the only known DEAD‐box protein having a specificity domain capable of direct high affinity binding to its RNA target. The specificity domain adopts a relatively common RNA recognition motif fold (RRM) but interacts with RNA in a novel non‐canonical manner. I will present the crystal structure of the specificity domain of YxiN bound to its ribosomal RNA target and discuss the role that the structure has played in clarifying previously puzzling biochemical data and in enhancing our understanding of the function of this helicase in ribosome biogenesis and maturation.
For disability-related accommodations, including dietary accommodations, please visit www.ada.umb.edu two weeks prior to the event.