NMR structure of the histidine kinase domain of the E. coli osmosensor EnvZ

Tanaka, Toŝhiyuki; Saha, Soumitra K.; Tomomori, Chieri; Ishima, Rieko; Liu, Dingjiang; Tong, Kit I.; Park, Heiyoung; Dutta, Rinku; Qin, Ling; Swindells, Mark B.; Yamazaki, Toshimasa; Ono, Akira; Kainosho, Masatsune; Inouye, Masayori; Ikura, Mitsuhiko

doi:10.1038/23968

Cited by 253 publications

(230 citation statements)

References 18 publications

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“…The C-terminal cytoplasmic domain is organized into a four-helix bundle subdomain, with two helices being contributed by each monomer and linked to the ATP-binding kinase subdomain through a flexible linker. Structures of the four-helix bundle (PDB: 1JOY) (19) and the kinase subdomains (PDB: 1BXD) (20) solved by NMR offered structural insights into the isolated subdomains at low osmolality. Crystallographic structures of the two subdomains tethered together were solved recently in a chimeric construct of EnvZ formed from Thermotoga maritima and Escherichia coli EnvZ (PDB: 4KP4) (21), representing the structure of EnvZ at high osmolality (Fig.…”

Section: Introductionmentioning

confidence: 99%

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

Ghosh

Wang

Ramesh

et al. 2017

Biophysical Journal

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Membrane-anchored receptors are essential cellular signaling elements for stimulus sensing, propagation, and transmission inside cells. However, the contributions of lipid interactions to the function and dynamics of embedded receptor kinases have not been described in detail. In this study, we used amide hydrogen/deuterium exchange mass spectrometry, a sensitive biophysical approach, to probe the dynamics of a membrane-embedded receptor kinase, EnvZ, together with functional assays to describe the role of lipids in receptor kinase function. Our results reveal that lipids play an important role in regulating receptor function through interactions with transmembrane segments, as well as through peripheral interactions with nonembedded domains. Specifically, the lipid membrane allosterically modulates the activity of the embedded kinase by altering the dynamics of a glycine-rich motif that is critical for phosphotransfer from ATP. This allostery in EnvZ is independent of membrane composition and involves direct interactions with transmembrane and periplasmic segments, as well as peripheral interactions with nonembedded domains of the protein. In the absence of the membrane-spanning regions, lipid allostery is propagated entirely through peripheral interactions. Whereas lipid allostery impacts the phosphotransferase function of the kinase, extracellular stimulus recognition is mediated via a four-helix bundle subdomain located in the cytoplasm, which functions as the osmosensing core through osmolality-dependent helical stabilization. Our findings emphasize the functional modularity in a membrane-embedded kinase, separated into membrane association, phosphotransferase function, and stimulus recognition. These components are integrated through long-range communication relays, with lipids playing an essential role in regulation.

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Section: Introductionmentioning

confidence: 99%

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

Ghosh

Wang

Ramesh

et al. 2017

Biophysical Journal

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“…The cytoplasmic domain has been further dissected into three subdomains, the linker region, domain A, and domain B, in which the latter two form the catalytic core of EnvZ, harboring both kinase and phosphatase functions (3). NMR structures of both domain A and domain B have been solved (4,5). Biochemical analysis has revealed that the domain A of the EnvZ is responsible for the dimerization, phosphotransfer and phosphatase functions, and domain B binds ATP and catalytically assists the enzymatic function of domain A (3,6).…”

mentioning

confidence: 99%

Analysis of the Role of the EnvZ Linker Region in Signal Transduction Using a Chimeric Tar/EnvZ Receptor Protein, Tez1

Zhu

Inouye

2003

Journal of Biological Chemistry

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Tez1 is a chimeric protein in which the periplasmic and transmembrane domains of Tar, a chemosensor, are fused to the cytoplasmic catalytic domain of EnvZ, an osmosensing histidine kinase, through the EnvZ linker. Unlike Taz1 (a similar hybrid with the Tar linker), Tez1 could not respond to Tar ligand, aspartate, whereas single Ala insertion at the transmembrane/linker junction, as seen in Tez1A1, restored the aspartate-regulatable phenotype. Analysis of the Ala insertion site requirement and the nature of the insertion residue on the phenotype of Tez1 indicated that a junction region between the transmembrane domain and the predicted helix I in the linker is critical to signal transduction. Random mutagenesis revealed that P185Q mutation in the Tez1 linker restored the aspartate-regulatable phenotype. Substitution mutations at Pro-185 further demonstrated that specific residues are required at this site for an aspartate response. None of the hybrid receptors constructed with different Tar/EnvZ fusion sites in the linker could respond to aspartate, suggesting that specific interactions between the two predicted helices in the linker are important for the linker function. In addition, a mutation (F220D) known to cause an OmpC c phenotype in EnvZ resulted in similar OmpC c phenotypes in both Tez1A1 and Tez1, indicating the importance of the predicted helix II in signal propagation. Together, we propose that the N-terminal junction region modulates the alignment between the two helices in the linker upon signal input. In turn helix II propagates the resultant conformational signal into the downstream catalytic domain of EnvZ to regulate its bifunctional enzymatic activities.EnvZ, a histidine kinase osmosensor, locates on the inner membrane of Escherichia coli. It is composed of a periplasmic domain, transmembrane domains, and a cytoplasmic domain (1, 2). The cytoplasmic domain has been further dissected into three subdomains, the linker region, domain A, and domain B, in which the latter two form the catalytic core of EnvZ, harboring both kinase and phosphatase functions (3). NMR structures of both domain A and domain B have been solved (4, 5). Biochemical analysis has revealed that the domain A of the EnvZ is responsible for the dimerization, phosphotransfer and phosphatase functions, and domain B binds ATP and catalytically assists the enzymatic function of domain A (3, 6). The spatial arrangement between these two domains appears to be crucial for the modulation of EnvZ enzymatic activities (6). Previous studies suggest that EnvZ senses the extracellular osmolarity changes, transmits the signal through its transmembrane domain, and then modulates the kinase/phosphatase ratio of the cytoplasmic catalytic domain, which controls the cellular concentration of phosphorylated OmpR to mediate the reciprocal expression of the two major outer membrane porin proteins OmpF and OmpC (2, 7-11).Although the exact ligand for EnvZ remains unknown, two kinds of chimeric receptors have been constructed in which the periplasmic an...

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“…If FeuQ has both kinase and phosphatase activities, we hypothesized that selective elimination of kinase activity by mutation would create dominantnegative variants due to unchecked phosphatase activity. This is consistent with observations in other bifunctional sensor kinases (Atkinson & Ninfa, 1993;Hsing & Silhavy, 1997;Tanaka et al, 1998). To test this hypothesis, we created two FeuQ variants that were predicted to eliminate kinase activity while potentially leaving phosphatase activity intact.…”

Section: Does the Feun/q Interaction Cause An Increase In Feuq Phosphmentioning

confidence: 49%

“…An identical mutation in the well-characterized SK EnvZ was shown to eliminate kinase but not phosphatase activity (Hsing & Silhavy, 1997). Another variant, FeuQ (G398A), changes a highly conserved Gly residue previously shown to be critical for ATP binding and autophosphorylation (Tanaka et al, 1998). In the experiment shown in Fig.…”

Section: Does the Feun/q Interaction Cause An Increase In Feuq Phosphmentioning

confidence: 96%

Genetic analysis of signal integration by the Sinorhizobium meliloti sensor kinase FeuQ

2015

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NMR structure of the histidine kinase domain of the E. coli osmosensor EnvZ

Cited by 253 publications

References 18 publications

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays

Analysis of the Role of the EnvZ Linker Region in Signal Transduction Using a Chimeric Tar/EnvZ Receptor Protein, Tez1

Genetic analysis of signal integration by the Sinorhizobium meliloti sensor kinase FeuQ

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