Dynamics of backbone conformational heterogeneity in Bacillus subtilis ribonuclease P protein.
Interconversion of protein conformations is imperative to function, as evidenced by conformational changes associated with enzyme catalytic cycles, ligand binding and post-translational modifications. In this study, we used 15N NMR relaxation experiments to probe the fast (i.e., ps-ns) and slow (i.e., micros-ms) conformational dynamics of Bacillus subtilis ribonuclease P protein (P protein) in its folded state, bound to two sulfate anions. Using the Lipari-Szabo mapping method [Andrec, M., Montelione, G. T., and Levy, R. M. (2000) J. Biomol. NMR 18, 83-100] to interpret the data, we find evidence for P protein dynamics on the mus-ms time scale in the ensemble. The residues that exhibit these slow internal motions are found in regions that have been previously identified as part of the P protein-P RNA interface. These results suggest that structural flexibility within the P protein ensemble may be important for proper RNase P holoenzyme assembly and/or catalysis.
Department of Biochemistry, Box 3711, Duke University Medical Center, Durham, North Carolina 27710, USA.
Christopher H
CH
Henkels
Yu-Chu
YC
Chang
Stacy I
SI
Chamberlin
Terrence G
TG
Oas
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D043262:Ribonuclease P / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D043262:Ribonuclease P