Poster abstracts

Poster number 20 submitted by Yiren Xu

Solution Structure of an RNase P Protein-Protein Complex: RPP29-RPP21 from Pyrococcus furiosis

Yiren Xu (OSBP, Department of Biochemistry), Carlos D. Amero (Biophysics Graduate Program, Department of Biochemistry), Dileep K. Pulukkunat (OSBP, Department of biochemistry), Venkat Gopalan (OSBP, Department of biochemistry), Mark P. Foster (OSBP, Department of Biochemistry, Biophysics Graduate Program)

Abstract:
RNase P is a ribonucleoprotein (RNP) enzyme that catalyzes the Mg²⁺-dependent 5’ maturation of precursor tRNA. In all domains of life, it is a ribozyme: the RNase P RNA (RPR) component has been demonstrated to be responsible for catalysis. However, various numbers of RNase P proteins (RPPs) are required in vivo, depending on the domain of life. Four RPPs are associated with the archaeal RPR, and function in pairs (RPP29-RPP21 and RPP30-POP5). We used solution NMR spectroscopy to determine the three-dimensional structure of the protein-protein complex comprising Pyrococcus furiosis (Pfu) RPP29 and RPP21. Both proteins perform additional folding coupled to partner binding, and these induced secondary structures participate in interface formation and grant stability to the complex. In addition to the revealing the intermolecular contacts that fasten this 30-kDa binary complex, the structure identifies surfaces rich in conserved basic residues likely vital for recognition of the RPR and/or precursor tRNA. Furthermore, the RPP29-RPP21 complex is shown to bind to the specificity domain of RPR. Our results provide a valuable starting point for understanding protein-aided RNA catalysis and building a three-dimensional model of this ancient RNPzyme.

References:
Solution Structure of an RNase P Protein-Protein Complex. Formation of the 29 kDa Complex Between Pyrococcus furiosus RPP21 and RPP29 is Accompanied by Coupled Protein Folding, and Highlights Critical Features for Protein-Protein and Protein-RNA Interactions. Xu Y. et al., (In preparation)

Keywords: RNase P, protein-protein interaction, NMR