5U56
Structure of Francisella tularensis heterodimeric SspA (MglA-SspA)
Summary for 5U56
| Entry DOI | 10.2210/pdb5u56/pdb |
| Descriptor | Stringent starvation protein A, Macrophage growth locus A, GLYCEROL, ... (6 entities in total) |
| Functional Keywords | stringent starvation protein a, macrophage growth locus a, gst-fold, transcription |
| Biological source | Francisella tularensis More |
| Total number of polymer chains | 4 |
| Total formula weight | 96944.91 |
| Authors | Cuthbert, B.J.,Schumacher, M.A.,Brennan, R.G. (deposition date: 2016-12-06, release date: 2017-08-16, Last modification date: 2023-10-04) |
| Primary citation | Cuthbert, B.J.,Ross, W.,Rohlfing, A.E.,Dove, S.L.,Gourse, R.L.,Brennan, R.G.,Schumacher, M.A. Dissection of the molecular circuitry controlling virulence in Francisella tularensis. Genes Dev., 31:1549-1560, 2017 Cited by PubMed Abstract: the etiological agent of tularemia, is one of the most infectious bacteria known. Because of its extreme pathogenicity, is classified as a category A bioweapon by the US government. virulence stems from genes encoded on the pathogenicity island (FPI). An unusual set of regulators-the heteromeric macrophage growth locus protein A (MglA)-stringent starvation protein A (SspA) complex and the DNA-binding protein pathogenicity island gene regulator (PigR)-activates FPI transcription and thus is essential for virulence. Intriguingly, the second messenger, guanosine-tetraphosphate (ppGpp), which is produced during infection, is also involved in coordinating virulence; however, its role has been unclear. Here we identify MglA-SspA as a novel ppGpp-binding complex and describe structures of apo- and ppGpp-bound MglA-SspA. We demonstrate that MglA-SspA, which binds RNA polymerase (RNAP), also interacts with the C-terminal domain of PigR, thus anchoring the (MglA-SspA)-RNAP complex to the FPI promoter. Furthermore, we show that MglA-SspA must be bound to ppGpp to mediate high-affinity interactions with PigR. Thus, these studies unveil a novel pathway different from those described previously for regulation of transcription by ppGpp. The data also indicate that pathogenesis is controlled by a highly interconnected molecular circuitry in which the virulence machinery directly senses infection via a small molecule stress signal. PubMed: 28864445DOI: 10.1101/gad.303701.117 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.65 Å) |
Structure validation
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