scholarly journals Xanthomonas campestris sensor kinase HpaS co‐opts the orphan response regulator VemR to form a branched two‐component system that regulates motility

2020 ◽  
Vol 21 (3) ◽  
pp. 360-375
Author(s):  
Rui‐Fang Li ◽  
Xin‐Xin Wang ◽  
Liu Wu ◽  
Li Huang ◽  
Qi‐Jian Qin ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Response Regulator ◽  
Sensor Kinase ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals A Novel Three-Protein Two-Component System Provides a Regulatory Twist on an Established Circuit To Modulate Expression of the cbbI Region of Rhodopseudomonas palustris CGA010

2006 ◽  
Vol 188 (8) ◽  
pp. 2780-2791 ◽  
Author(s):  
Simona Romagnoli ◽  
F. Robert Tabita
Keyword(s):  
Response Regulator ◽  
Rhodopseudomonas Palustris ◽  
Sensor Kinase ◽  
Response Regulators ◽  
Transcription Activator ◽  
Two Component System ◽  
Bisphosphate Carboxylase ◽  
Control Of Gene Expression ◽  
Component System ◽  
Two Component

ABSTRACT A novel two-component system has been identified in the cbbI region of the nonsulfur purple photosynthetic bacterium Rhodopseudomonas palustris. Genes encoding this system, here designated cbbRRS, are juxtaposed between the divergently transcribed transcription activator gene, cbbR, and the form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) genes, cbbLS. The three genes of the cbbRRS system represent a variation of the well-known two-component signal transduction systems, as there are a transmembrane hybrid sensor kinase and two response regulators, with no apparent DNA binding domain associated with any of the three proteins encoded by these genes. In this study, we showed that the membrane-bound full-length kinase undergoes autophosphorylation and transfers phosphate to both response regulators. A soluble, truncated version of the kinase was subsequently prepared and found to catalyze phosphorylation of response regulator 1 but not response regulator 2, implying that conformational changes and/or sequence-specific regions of the kinase are important for discriminating between the two response regulators. Analyses indicated that a complex network of control of gene expression must occur, with CbbR required for the expression of the cbbLS genes but dispensable for the synthesis of form II RubisCO (encoded by cbbM). The CbbRRS proteins specifically affected the activity and accumulation of form I RubisCO (CbbLS), as revealed by analyses of nonpolar, unmarked gene deletions. A tentative model of regulation suggested that changes in the phosphotransfer activity of the sensor kinase, possibly in response to a redox metabolic signal, cause modulation of the activity and synthesis of form I RubisCO.

scholarly journals In the Staphylococcus aureus Two-Component System sae, the Response Regulator SaeR Binds to a Direct Repeat Sequence and DNA Binding Requires Phosphorylation by the Sensor Kinase SaeS

2010 ◽  
Vol 192 (8) ◽  
pp. 2111-2127 ◽  
Author(s):  
Fei Sun ◽  
Chunling Li ◽  
Dowon Jeong ◽  
Changmo Sohn ◽  
Chuan He ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Binding ◽  
Response Regulator ◽  
Direct Repeat ◽  
Repeat Sequence ◽  
Sensor Kinase ◽  
Two Component System ◽  
Component System ◽  
Direct Repeat Sequence ◽  
Two Component

ABSTRACT Staphylococcus aureus uses the SaeRS two-component system to control the expression of many virulence factors such as alpha-hemolysin and coagulase; however, the molecular mechanism of this signaling has not yet been elucidated. Here, using the P1 promoter of the sae operon as a model target DNA, we demonstrated that the unphosphorylated response regulator SaeR does not bind to the P1 promoter DNA, while its C-terminal DNA binding domain alone does. The DNA binding activity of full-length SaeR could be restored by sensor kinase SaeS-induced phosphorylation. Phosphorylated SaeR is more resistant to digestion by trypsin, suggesting conformational changes. DNase I footprinting assays revealed that the SaeR protection region in the P1 promoter contains a direct repeat sequence (GTTAAN6GTTAA [where N is any nucleotide]). This sequence is critical to the binding of phosphorylated SaeR. Mutational changes in the repeat sequence greatly reduced both the in vitro binding of SaeR and the in vivo function of the P1 promoter. From these results, we concluded that SaeR recognizes the direct repeat sequence as a binding site and that binding requires phosphorylation by SaeS.

scholarly journals PhoB transcriptional activator binds hierarchically to pho box promoters

2012 ◽  
Vol 393 (10) ◽  
pp. 1165-1171 ◽  
Author(s):  
Alexandre G. Blanco ◽  
Albert Canals ◽  
Miquel Coll
Keyword(s):  
Crystal Structure ◽  
Molecular Mechanisms ◽  
Phosphate Uptake ◽  
Response Regulator ◽  
Sensor Kinase ◽  
Two Component System ◽  
Component System ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Two Component

Abstract The PhoR-PhoB phosphorelay is a bacterial two-component system that activates the transcription of several genes involved in phosphate uptake and assimilation. The response begins with the autophosphorylation of the sensor kinase PhoR, which activates the response regulator PhoB. Upon binding to the pho box DNA sequence, PhoB recruits the RNA polymerase and thereby activates the transcription of specific genes. To unveil hitherto unknown molecular mechanisms along the activation pathway, we report biochemical data characterizing the PhoB binding to promoters containing multiple pho boxes and describe the crystal structure of two PhoB DNA-binding domains bound in tandem to a 26-mer DNA.

scholarly journals Phosphorelay as the Sole Physiological Route of Signal Transmission by the Arc Two-Component System ofEscherichia coli

2000 ◽  
Vol 182 (13) ◽  
pp. 3858-3862 ◽  
Author(s):  
Ohsuk Kwon ◽  
Dimitris Georgellis ◽  
E. C. C. Lin
Keyword(s):  
Response Regulator ◽  
Signal Transmission ◽  
Phosphoryl Group ◽  
Sensor Kinase ◽  
Wild Type ◽  
Two Component System ◽  
Component System ◽  
Group Transfer ◽  
Two Component

ABSTRACT The Arc two-component system, comprising a tripartite sensor kinase (ArcB) and a response regulator (ArcA), modulates the expression of numerous genes involved in respiratory functions. In this study, the steps of phosphoryl group transfer from phosphorylated ArcB to ArcA were examined in vivo by using single copies of wild-type and mutantarcB alleles. The results indicate that the signal transmission occurs solely by His-Asp-His-Asp phosphorelay.

scholarly journals Phosphotransfer Reactions of the CbbRRS Three-Protein Two- Component System from Rhodopseudomonas palustris CGA010 Appear To Be Controlled by an Internal Molecular Switch on the Sensor Kinase

2006 ◽  
Vol 189 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Simona Romagnoli ◽  
F. Robert Tabita
Keyword(s):  
Response Regulator ◽  
Rhodopseudomonas Palustris ◽  
Molecular Switch ◽  
Sensor Kinase ◽  
Two Component System ◽  
Conserved Residues ◽  
Component System ◽  
Receiver Domain ◽  
Two Component

ABSTRACT The CbbRRS system is an atypical three-protein two-component system that modulates the expression of the cbb I CO2 fixation operon of Rhodopseudomonas palustris, possibly in response to a redox signal. It consists of a membrane-bound hybrid sensor kinase, CbbSR, with a transmitter and receiver domain, and two response regulator proteins, CbbRR1 and CbbRR2. No detectable helix-turn-helix DNA binding domain is associated with either response regulator, but an HPt domain and a second receiver domain are predicted at the C-terminal region of CbbRR1 and CbbRR2, respectively. The abundance of conserved residues predicted to participate in a His-Asp phosphorelay raised the question of their de facto involvement. In this study, the role of the multiple receiver domains was elucidated in vitro by generating site-directed mutants of the putative conserved residues. Distinct phosphorylation patterns were obtained with two truncated versions of the hybrid sensor kinase, CbbSRT189 and CbbSRR96 (CbbSR beginning at residues T189 and R96, respectively). These constructs also exhibited substantially different affinities for ATP and phosphorylation stability, which was found to be dependent on a conserved Asp residue (Asp-696) within the kinase receiver domain. Asp-696 also played an important role in defining the specificity of phosphorylation for response regulators CbbRR1 or CbbRR2, and this residue appeared to act in conjunction with residues within the region from Arg-96 to Thr-189 at the N terminus of the sensor kinase. The net effect of concerted interactions at these distinct regions of CbbSR created an internal molecular switch that appears to coordinate a unique branched phosphorelay system.

The Bacillus subtilis YdfHI two-component system regulates the transcription of ydfJ, a member of the RND superfamily

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1769-1778 ◽  
Author(s):  
Masakuni Serizawa ◽  
Junichi Sekiguchi
Keyword(s):  
Bacillus Subtilis ◽  
Promoter Region ◽  
Response Regulator ◽  
Repeat Sequence ◽  
Sensor Kinase ◽  
Two Component System ◽  
Component System ◽  
Dnase I Footprinting ◽  
Two Component ◽  
Gel Shift Assay

The ydfHI genes encode a sensor kinase and a response regulator forming a two-component system. ydfJ is located downstream of ydfHI, and belongs to the RND (resistance-nodulation-cell division) superfamily, which is present in most major organisms. Four genes (secDF, yerP, ydfJ and ydgH) in Bacillus subtilis belong to this family. This study revealed that the YdfHI two-component system regulates ydfJ transcription. A gel shift assay using histidine-tagged YdfI (h-YdfI) showed that it directly binds to the ydfJ promoter region. Moreover, DNase I footprinting analysis revealed a tandem repeat sequence consisting of two conserved 12-mer sequences (GCCCRAAYGTAC) within the h-YdfI-binding site.

scholarly journals Identification of a Second Two-Component Signal Transduction System That Controls Fosfomycin Tolerance and Glycerol-3-Phosphate Uptake

2014 ◽  
Vol 197 (5) ◽  
pp. 861-871 ◽  
Author(s):  
Kumiko Kurabayashi ◽  
Yuko Hirakawa ◽  
Koichi Tanimoto ◽  
Haruyoshi Tomita ◽  
Hidetada Hirakawa
Keyword(s):  
Phosphate Uptake ◽  
Response Regulator ◽  
Anaerobic Respiration ◽  
Regulatory System ◽  
Carbon Substrate ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Two Component ◽  
Biological Cost

Particular interest in fosfomycin has resurfaced because it is a highly beneficial antibiotic for the treatment of refractory infectious diseases caused by pathogens that are resistant to other commonly used antibiotics. The biological cost to cells of resistance to fosfomycin because of chromosomal mutation is high. We previously found that a bacterial two-component system, CpxAR, induces fosfomycin tolerance in enterohemorrhagicEscherichia coli(EHEC) O157:H7. This mechanism does not rely on irreversible genetic modification and allows EHEC to relieve the fitness burden that results from fosfomycin resistance in the absence of fosfomycin. Here we show that another two-component system, TorSRT, which was originally characterized as a regulatory system for anaerobic respiration utilizing trimethylamine-N-oxide (TMAO), also induces fosfomycin tolerance. Activation of the Tor regulatory pathway by overexpression oftorR, which encodes the response regulator, or addition of TMAO increased fosfomycin tolerance in EHEC. We also show that phosphorylated TorR directly represses the expression ofglpT, a gene that encodes a symporter of fosfomycin and glycerol-3-phosphate, and activation of the TorR protein results in the reduced uptake of fosfomycin by cells. However, cells in which the Tor pathway was activated had an impaired growth phenotype when cultured with glycerol-3-phosphate as a carbon substrate. These observations suggest that the TorSRT pathway is the second two-component system to reversibly control fosfomycin tolerance and glycerol-3-phosphate uptake in EHEC, and this may be beneficial for bacteria by alleviating the biological cost. We expect that this mechanism could be a potential target to enhance the utility of fosfomycin as chemotherapy against multidrug-resistant pathogens.

scholarly journals The two-component system CopRS maintains femtomolar levels of free copper in the periplasm of Pseudomonas aeruginosa using a phosphatase-based mechanism

2020 ◽  
Author(s):  
Lorena Novoa-Aponte ◽  
Fernando C. Soncini ◽  
José M. Argüello
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phosphatase Activity ◽  
Response Regulator ◽  
Redox Enzymes ◽  
Two Component System ◽  
Component System ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Systems Control

ABSTRACTTwo component systems control periplasmic Cu+ homeostasis in Gram-negative bacteria. In characterized systems such as Escherichia coli CusRS, upon Cu+ binding to the periplasmic sensing domain of CusS, a cytoplasmic phosphotransfer domain phosphorylates the response regulator CusR. This drives the expression of efflux transporters, chaperones, and redox enzymes to ameliorate metal toxic effects. Here, we show that the Pseudomonas aeruginosa two component sensor histidine kinase CopS exhibits a Cu-dependent phosphatase activity that maintains a non-phosphorylated CopR when the periplasmic Cu levels are below its activation threshold. Upon Cu+ binding to the sensor, the phosphatase activity is blocked and the phosphorylated CopR activates transcription of the CopRS regulon. Supporting the model, mutagenesis experiments revealed that the ΔcopS strain showed constitutive high expression of the CopRS regulon, lower intracellular Cu+ levels, and larger Cu tolerance when compared to wild type cells. The invariant phospho-acceptor residue His235 of CopS was not required for the phosphatase activity itself, but necessary for its Cu-dependency. To sense the metal, the periplasmic domain of CopS binds two Cu+ ions at its dimeric interface. Homology modeling of CopS based on CusS structure (four Ag+ binding sites) clearly explains the different binding stoichiometries in both systems. Interestingly, CopS binds Cu+/2+ with 30 × 10−15 M affinities, pointing to the absence of free (hydrated) Cu+/2+ in the periplasm.IMPORTANCECopper is a micronutrient required as cofactor in redox enzymes. When free, copper is toxic, mismetallating proteins, and generating damaging free radicals. Consequently, copper overload is a strategy that eukaryotic cells use to combat pathogens. Bacteria have developed copper sensing transcription factors to control copper homeostasis. The cell envelope is the first compartment that has to cope with copper stress. Dedicated two component systems control the periplasmic response to metal overload. This manuscript shows that the copper sensing two component system present in Pseudomonadales exhibits a signal-dependent phosphatase activity controlling the activation of the response regulator, distinct from previously described periplasmic Cu sensors. Importantly, the data show that the sensor is activated by copper levels compatible with the absence of free copper in the cell periplasm. This emphasizes the diversity of molecular mechanisms that have evolved in various bacteria to manage the copper cellular distribution.

scholarly journals Degradation of cyclic diguanosine monophosphate by a hybrid two-component protein protects Azoarcus sp. strain CIB from toluene toxicity

2016 ◽  
Vol 113 (46) ◽  
pp. 13174-13179 ◽  
Author(s):  
Zaira Martín-Moldes ◽  
Blas Blázquez ◽  
Claudine Baraquet ◽  
Caroline S. Harwood ◽  
María T. Zamarro ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Response Regulator ◽  
Anaerobic Growth ◽  
Two Component System ◽  
Component System ◽  
Bacterial Physiology ◽  
Toxic Concentration ◽  
Two Component ◽  
Cyclic Diguanosine Monophosphate ◽  
Diguanosine Monophosphate

Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger that controls diverse functions in bacteria, including transitions from planktonic to biofilm lifestyles, virulence, motility, and cell cycle. Here we describe TolR, a hybrid two-component system (HTCS), from the β-proteobacterium Azoarcus sp. strain CIB that degrades c-di-GMP in response to aromatic hydrocarbons, including toluene. This response protects cells from toluene toxicity during anaerobic growth. Whereas wild-type cells tolerated a sudden exposure to a toxic concentration of toluene, a tolR mutant strain or a strain overexpressing a diguanylate cyclase gene lost viability upon toluene shock. TolR comprises an N-terminal aromatic hydrocarbon-sensing Per–Arnt–Sim (PAS) domain, followed by an autokinase domain, a response regulator domain, and a C-terminal c-di-GMP phosphodiesterase (PDE) domain. Autophosphorylation of TolR in response to toluene exposure initiated an intramolecular phosphotransfer to the response regulator domain that resulted in c-di-GMP degradation. The TolR protein was engineered as a functional sensor histidine kinase (TolRSK) and an independent response regulator (TolRRR). This classic two-component system (CTCS) operated less efficiently than TolR, suggesting that TolR was evolved as a HTCS to optimize signal transduction. Our results suggest that TolR enables Azoarcus sp. CIB to adapt to toxic aromatic hydrocarbons under anaerobic conditions by modulating cellular levels of c-di-GMP. This is an additional role for c-di-GMP in bacterial physiology.

scholarly journals The ArcB Sensor Kinase of Escherichia coli Autophosphorylates by an Intramolecular Reaction

2010 ◽  
Vol 192 (6) ◽  
pp. 1735-1739 ◽  
Author(s):  
Gabriela R. Peña-Sandoval ◽  
Dimitris Georgellis
Keyword(s):  
Response Regulator ◽  
Bond Formation ◽  
Sensor Kinase ◽  
Two Component System ◽  
Histidine Kinases ◽  
Intramolecular Reaction ◽  
Redox Active ◽  
Intermolecular Disulfide Bond ◽  
Two Component ◽  
Respiratory Conditions

ABSTRACT The Arc two-component system, comprising the ArcB sensor kinase and the ArcA response regulator, modulates the expression of numerous genes in response to the respiratory conditions of growth. ArcB is a tripartite histidine kinase whose activity is regulated by the oxidation of two cytosol-located redox-active cysteine residues that participate in intermolecular disulfide bond formation. Here we show that ArcB autophosphorylates through an intramolecular reaction which diverges from the usually envisaged intermolecular autophosphorylation of homodimeric histidine kinases.

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