title: Structural study of the partially disordered full-length δ subunit of RNA polymerase from Bacillus subtilis.
abstract: The partially disordered δ 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 β-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 δ subunit consists of a well-ordered N-terminal domain and a flexible C-terminal domain that exhibits a complex hierarchy of partial ordering.
authors.affiliation: Faculty of Science, NCBR and CEITEC MU, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic).
authors.forename: Veronika
authors.initials: V
authors.lastname: Papoušková
authors.forename: Pavel
authors.initials: P
authors.lastname: Kadeřávek
authors.forename: Olga
authors.initials: O
authors.lastname: Otrusinová
authors.forename: Alžbeta
authors.initials: A
authors.lastname: Rabatinová
authors.forename: Hana
authors.initials: H
authors.lastname: ŠSanderová
authors.forename: Jiří
authors.initials: J
authors.lastname: Nováček
authors.forename: Libor
authors.initials: L
authors.lastname: Krásný
authors.forename: Vladimír
authors.initials: V
authors.lastname: Sklenář
authors.forename: Lukáš
authors.initials: L
authors.lastname: Žídek
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D012321:DNA-Directed RNA Polymerases
keywords: NMR spectroscopy; RNA polymerase; partially disordered proteins; protein structures; δ subunit