Structural Study of the Partially Disordered Full-Length delta Subunit of RNA Polymerase from Bacillus subtilis
| Authors | |
|---|---|
| Year of publication | 2013 |
| Type | Article in Periodical |
| Magazine / Source | ChemBioChem |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.ncbi.nlm.nih.gov/pubmed/23868186 |
| Doi | http://dx.doi.org/10.1002/cbic.201300226 |
| Field | Biochemistry |
| Keywords | NMR spectroscopy; RNA polymerase; partially disordered proteins; protein structures; delta subunit |
| Description | The partially disordered delta subunit of RNA polymerase was studied by various NMR techniques. The structure of the well-folded N-terminal domain was determined based on inter-proton distances in NOESY spectra. The obtained structural model was compared to the previously determined structure of a truncated construct (lacking the C-terminal domain). Only marginal differences were identified, thus indicating that the first structural model was not significantly compromised by the absence of the C-terminal domain. Various 15 N relaxation experiments were employed to describe the flexibility of both domains. The relaxation data revealed that the C-terminal domain is more flexible, but its flexibility is not uniform. By using paramagnetic labels, transient contacts of the C-terminal tail with the N-terminal domain and with itself were identified. A propensity of the C-terminal domain to form beta-type structures was obtained by chemical shift analysis. Comparison with the paramagnetic relaxation enhancement indicated a well-balanced interplay of repulsive and attractive electrostatic interactions governing the conformational behavior of the C-terminal domain. The results showed that the delta subunit consists of a well-ordered N-terminal domain and a flexible C-terminal domain that exhibits a complex hierarchy of partial ordering. |
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