6weg

Structure of Ft (MglA-SspA)-ppGpp-PigR peptide complex

spinqualitylabelsall models 6weg, resolution 2.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6weg is a 5 chain structure with sequence from Francisella tularensis and Francisella tularensis subsp. tularensis SCHU S4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.95Å Ligands: G4P, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q5NHJ6_FRATT Publication Abstract from PubMed The bacterium Francisella tularensis (Ft) is one of the most infectious agents known. Ft virulence is controlled by a unique combination of transcription regulators: the MglA-SspA heterodimer, PigR, and the stress signal, ppGpp. MglA-SspA assembles with the sigma(70)-associated RNAP holoenzyme (RNAPsigma(70)), forming a virulence-specialized polymerase. These factors activate Francisella pathogenicity island (FPI) gene expression, which is required for virulence, but the mechanism is unknown. Here we report FtRNAPsigma(70)-promoter-DNA, FtRNAPsigma(70)-(MglA-SspA)-promoter DNA, and FtRNAPsigma(70)-(MglA-SspA)-ppGpp-PigR-promoter DNA cryo-EM structures. Structural and genetic analyses show MglA-SspA facilitates sigma(70) binding to DNA to regulate virulence and virulence-enhancing genes. Our Escherichia coli RNAPsigma(70-)homodimeric EcSspA structure suggests this is a general SspA-transcription regulation mechanism. Strikingly, our FtRNAPsigma(70)-(MglA-SspA)-ppGpp-PigR-DNA structure reveals ppGpp binding to MglA-SspA tethers PigR to promoters. PigR in turn recruits FtRNAP alphaCTDs to DNA UP elements. Thus, these studies unveil a unique mechanism for Ft pathogenesis involving a virulence-specialized RNAP that employs two (MglA-SspA)-based strategies to activate virulence genes. Structural Basis for Virulence Activation of Francisella tularensis.,Travis BA, Ramsey KM, Prezioso SM, Tallo T, Wandzilak JM, Hsu A, Borgnia M, Bartesaghi A, Dove SL, Brennan RG, Schumacher MA Mol Cell. 2021 Jan 7;81(1):139-152.e10. doi: 10.1016/j.molcel.2020.10.035. Epub , 2020 Nov 19. PMID:33217319 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Stringent starvation protein 3D structures

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