1YAX

Cystal structure Analysis of S.typhimurium PhoQ sensor domain with Calcium

Summary for 1YAX

• Entry DOI: 10.2210/pdb1yax/pdb
• Descriptor: Virulence sensor protein phoQ, sensor domain, CALCIUM ION (3 entities in total)
• Functional Keywords: phoq; sensor domain; magnesium/calcium sensor; magnesium/calcium bound, transferase, signaling protein
• Biological source: Salmonella typhimurium
• Cellular location: Cell inner membrane; Multi-pass membrane protein (By similarity): P14147
• Total number of polymer chains: 4
• Total formula weight: 71837.37

Authors

Cho, U.S.,Xu, W. (deposition date: 2004-12-17, release date: 2005-12-27, Last modification date: 2024-02-14)

Primary citation

Cho, U.S.,Bader, M.W.,Amaya, M.F.,Daley, M.E.,Klevit, R.E.,Miller, S.I.,Xu, W.
Metal bridges between the PhoQ sensor domain and the membrane regulate transmembrane signaling.
J.Mol.Biol., 356:1193-1206, 2006

PubMed Abstract: Bacterial histidine kinases respond to environmental stimuli by transducing a signal from an extracytosolic sensor domain to a cytosolic catalytic domain. Among them, PhoQ promotes bacterial virulence and is tightly repressed by the divalent cations such as calcium and magnesium. We have determined the crystal structure of the PhoQ sensor domain from Salmonella typhimurium in the Ca2+-bound state, which reveals a highly negatively charged surface that is in close proximity to the inner membrane. This acidic surface binds at least three Ca2+, which mediate the PhoQ-membrane interaction. Mutagenesis analysis indicates that structural integrity at the membrane proximal region of the PhoQ sensor domain promotes metal-mediated repression. We propose that depletion or displacement of divalent cations leads to charge repulsion between PhoQ and the membrane, which initiates transmembrane signaling through a change in orientation between the PhoQ sensor domain and membrane. Therefore, both PhoQ and the membrane are required for extracytosolic sensing and transmembrane signaling.

PubMed: 16406409
DOI: 10.1016/j.jmb.2005.12.032

Experimental method

X-RAY DIFFRACTION (2.4 Å)