4D6X
Crystal structure of the receiver domain of NtrX from Brucella abortus
Summary for 4D6X
| Entry DOI | 10.2210/pdb4d6x/pdb |
| Descriptor | BACTERIAL REGULATORY, FIS FAMILY PROTEIN, IMIDAZOLE (3 entities in total) |
| Functional Keywords | signaling protein, brucellosis, two-component system, response regulator, rec domain, microaerobisis |
| Biological source | BRUCELLA ABORTUS |
| Total number of polymer chains | 4 |
| Total formula weight | 65537.62 |
| Authors | Klinke, S.,Fernandez, I.,Carrica, M.C.,Otero, L.H.,Goldbaum, F.A. (deposition date: 2014-11-18, release date: 2015-07-08, Last modification date: 2023-12-20) |
| Primary citation | Fernandez, I.,Otero, L.H.,Klinke, S.,Carrica, M.C.,Goldbaum, F.A. Snapshots of Conformational Changes Shed Light Into the Ntrx Receiver Domain Signal Transduction Mechanism J.Mol.Biol., 427:3258-, 2015 Cited by PubMed Abstract: Brucella abortus is an important pathogenic bacterium that has to overcome oxygen deficiency in order to achieve a successful infection. Previously, we proved that a two-component system formed by the histidine kinase NtrY and the response regulator NtrX is essential to achieve an adaptive response to low oxygen tension conditions. Even though the relevance of this signaling pathway has already been demonstrated in other microorganisms, its molecular activation mechanism has not yet been described in detail. In this article, we report the first crystal structures from different conformations of the NtrX receiver domain from B. abortus, and we propose a sequence of events to explain the structural rearrangements along the activation process. The analysis of the structures obtained in the presence of the phosphoryl group analog beryllofluoride led us to postulate that changes in the interface formed by the α4 helix and the β5 strand are important for the activation, producing a reorientation of the α5 helix. Also, a biochemical characterization of the NtrX receiver domain enzymatic activities was performed, describing its autophosphorylation and autodephosphorylation kinetics. Finally, the role of H85, an important residue, was addressed by site-directed mutagenesis. Overall, these results provide significant structural basis for understanding the response regulator activation in this bacterial two-component system. PubMed: 26113057DOI: 10.1016/J.JMB.2015.06.010 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.11 Å) |
Structure validation
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