6uu3

E. coli sigma-S transcription initiation complex with a 4-nt RNA and a CTP ("Old" crystal soaked with GTP, ATP, CTP, and ddTTP for 30 minutes)

spinqualitylabelsall models 6uu3, resolution 4.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6uu3 is a 9 chain structure with sequence from Escherichia coli, Escherichia coli K-12 and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 4.002Å Ligands: 2DT, CTP, D4M, GTP, MG, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RPOS_ECOLI Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the master transcriptional regulator of the stationary phase and the general stress response. Controls, positively or negatively, the expression of several hundred genes, which are mainly involved in metabolism, transport, regulation and stress management.[HAMAP-Rule:MF_00959] Protects stationary phase cells from killing induced by endoribonuclease MazF. Publication Abstract from PubMed In bacteria, the dissociable sigma subunit of the RNA polymerase (RNAP) is responsible for initiating RNA synthesis from specific DNA sites. As nascent RNA grows, downstream DNA unwinds and is pulled into the RNAP, causing stress accumulation and initiation complex destabilization. Processive transcription elongation requires at least partial separation of the sigma factor from the RNAP core enzyme. Here, we present a series of transcription complexes captured between the early initiation and elongation phases via in-crystal RNA synthesis and cleavage. Crystal structures of these complexes indicate that stress accumulation during transcription initiation is not due to clashing of the growing nascent RNA with the sigma(3.2) loop, but results from scrunching of the template strand DNA that is contained inside the RNAP by the sigma(3) domain. Our results shed light on how scrunching of template-strand DNA drives both abortive initiation and sigma-RNAP core separation to transition transcription from initiation to elongation. Structural Insights into Transcription Initiation from De Novo RNA Synthesis to Transitioning into Elongation.,Zuo Y, De S, Feng Y, Steitz TA iScience. 2020 Aug 11;23(9):101445. doi: 10.1016/j.isci.2020.101445. eCollection , 2020 Sep 25. PMID:32829286 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Sigma factor 3D structures

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