Probing the Folding Intermediate of Bacillus subtilis RNase P protein by NMR.

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Probing the Folding Intermediate of Bacillus subtilis RNase P protein by NMR.

Related Articles Probing the Folding Intermediate of Bacillus subtilis RNase P protein by NMR.

Biochemistry. 2010 Sep 15;

Authors: Chang YC, Franch WR, Oas TG

Protein folding intermediates are often imperative to overall folding processes and consequent biological functions. However, the low population and transient nature of the intermediate states often hinder the biochemical and biophysical characterization. Previous studies have demonstrated that Bacillus subtilis ribonuclease P protein (P protein) is conformationally heterogeneous and folds with multiphasic kinetics, indicating the presence of an equilibrium and kinetic intermediate in its folding mechanism. In this study, NMR spectroscopy was used to study the ensemble corresponding to this intermediate (I). The results indicate that the N-terminal and C-terminal helical regions are mostly unfolded in I.1H-15N HSQC NMR spectra collected as a function of pH suggest that the protonation of His 22 may play a major role in the energetics of the equilibria between the unfolded, intermediate, and folded state ensembles of P protein. NMR paramagnetic relaxation enhancement experiments were also used to locate the small anion binding sites in both the intermediate and folded ensembles. The results for the folded protein are consistent with the previously modeled binding regions. These structural insights suggest a possible role for I in the RNase P holoenzyme assembly process.

PMID: 20843005 [PubMed - as supplied by publisher]



Source: PubMed