1yax
From Proteopedia
| |||||||
| , resolution 2.40Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | phoQ (Salmonella typhimurium) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Cystal structure Analysis of S.typhimurium PhoQ sensor domain with Calcium
Overview
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.
About this Structure
1YAX is a Single protein structure of sequence from Salmonella typhimurium. Full crystallographic information is available from OCA.
Reference
Metal bridges between the PhoQ sensor domain and the membrane regulate transmembrane signaling., Cho US, Bader MW, Amaya MF, Daley ME, Klevit RE, Miller SI, Xu W, J Mol Biol. 2006 Mar 10;356(5):1193-206. Epub 2005 Dec 27. PMID:16406409
Page seeded by OCA on Mon Mar 31 01:01:16 2008
