Structural highlights
Function[RPOE_BACSU] Participates in both the initiation and recycling phases of transcription. In the presence of the delta subunit, RNAP displays an increased specificity of transcription, a decreased affinity for nucleic acids, and an increased efficiency of RNA synthesis because of enhanced recycling. May function in sigma factor switching. It displaces RNA bound to RNA polymerase in a binary complex. Publication Abstract from PubMedThe crystal structure of the N-terminal domain of the RNA polymerase delta subunit (Ndelta) from Bacillus subtilis solved at a resolution of 2.0A is compared with the NMR structure determined previously. The molecule crystallizes in the space group C222(1) with a dimer in the asymmetric unit. Importantly, the X-ray structure exhibits significant differences from the lowest energy NMR structure. In addition to the overall structure differences, structurally important beta sheets found in the NMR structure are not present in the crystal structure. We systematically investigated the cause of the discrepancies between the NMR and X-ray structures of Ndelta, addressing the pH dependence, presence of metal ions, and crystal packing forces. We convincingly showed that the crystal packing forces, together with the presence of Ni2+ ions, are the main reason for such a difference. In summary, the study illustrates that the two structural approaches may give unequal results, which need to be interpreted with care to obtain reliable structural information in terms of biological relevance. X-ray vs. NMR structure of N-terminal domain of delta-subunit of RNA polymerase.,Demo G, Papouskova V, Komarek J, Kaderavek P, Otrusinova O, Srb P, Rabatinova A, Krasny L, Zidek L, Sklenar V, Wimmerova M J Struct Biol. 2014 Jun 14. pii: S1047-8477(14)00137-3. doi:, 10.1016/j.jsb.2014.06.001. PMID:24937760[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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