Poster abstracts

Poster number 10 submitted by Brandon Crowe

The interactions between Archaeal RNase P components RPP30, Pop5, and the RPR

Brandon L. Crowe (Department of Chemistry and Biochemistry), Venkat Gopalan (Department of Chemistry and Biochemistry), Mark P. Foster (Department of Chemistry and Biochemistry)

Abstract:
Ribonuclease P (RNaseP) is an enzyme essential in all forms of life, and is composed of both RNA and protein subunits. Across the domains of life, the singular RNA moiety of this ribonucleoprotein (RNP) complex has been shown to be catalytic on its own in vitro, although the protein subunits are required for in vivo activity. The number of protein subunits varies from 1 in Bacteria to 9 or 10 in Eukarya. We have used nuclear magnetic resonance (NMR) to analyze a protein-protein interaction and used molecular modeling to model the protein-RNA interactions between various subunits of RNase P from the hyperthermophilic Archaeon Pyrococcus furiosus (Pfu). Pfu RNase P possesses five protein subunits, four of which form two binary pairs RPP21-RPP29 and RPP30-Pop5. Dynamic light scattering (DLS) indicates that the RPP30-Pop5 dimer forms a heterotetramer in solution. NMR chemical shift perturbations map the interaction surface for the complex between RPP30 and Pop5, in agreement with the crystallographic studies of a homologous pair from another Archaeon. Finally, structural homology involving the Pfu RPR and Pop5 with the bacterial RPR and C5 protein from Thermotoga maritima (Tma) enables the RPP30-Pop5 complex to be positioned onto a model of the Pfu RPR. These results continue to add insight into the interactions involved in RNP formation and will inform future efforts to elucidate assembly and structure of the whole RNase P complex.

Keywords: RNase P, Protein-Protein interaction, Protein-RNA interaction