Domain Analysis of ArcS, the Hybrid Sensor Kinase of the Shewanella oneidensis MR-1 Arc Two-Component System, Reveals Functional Differentiation of Its Two Receiver Domains

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.

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Delineation of the pH-responsive regulon controlled by the Helicobacter pylori ArsRS two- component system

Infection and Immunity ◽

10.1128/iai.00597-20 ◽

2021 ◽

Author(s):

John T. Loh ◽

Miranda V. Shum ◽

Scott D.R. Jossart ◽

Anne M. Campbell ◽

Neha Sawhney ◽

...

Keyword(s):

Gene Expression ◽

Helicobacter Pylori ◽

Differentially Expressed ◽

Sensor Kinase ◽

Ph Responsive ◽

Two Component System ◽

Component System ◽

Wide Range ◽

Two Component ◽

H Pylori

Helicobacter pylori encounters a wide range of pH within the human stomach. In a comparison of H. pylori cultured in vitro under neutral or acidic conditions, about 15% of genes are differentially expressed, and corresponding changes are detectable for many of the encoded proteins. The ArsRS two-component system (TCS), comprised of the sensor kinase ArsS and its cognate response regulator ArsR, has an important role in mediating pH-responsive changes in H. pylori gene expression. In this study, we sought to delineate the pH-responsive ArsRS regulon and further define the role of ArsR in pH-responsive gene expression. We compared H. pylori strains containing an intact ArsRS system with an arsS null mutant or strains containing site-specific mutations of a conserved aspartate residue (D52) in ArsR, which is phosphorylated in response to signals relayed by the cognate sensor kinase ArsS. We identified 178 genes that were pH-responsive in strains containing an intact ArsRS system but not in ΔarsS or arsR mutants. These constituents of the pH-responsive ArsRS regulon include genes involved in acid acclimatization (ureAB, amidases), oxidative stress responses (katA, sodB), transcriptional regulation related to iron or nickel homeostasis (fur, nikR), and genes encoding outer membrane proteins [including sabA, alpA, alpB, hopD (labA), and horA]. When comparing H. pylori strains containing an intact ArsRS TCS with arsRS mutants, each cultured at neutral pH, relatively few genes are differentially expressed. Collectively, these data suggest that ArsRS-mediated gene regulation has an important role in H. pylori adaptation to changing pH conditions.

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Regulation of natural competence by the orphan two-component system sensor kinase ChiS involves a non-canonical transmembrane regulator inVibrio cholerae

Molecular Microbiology ◽

10.1111/mmi.12462 ◽

2013 ◽

Vol 91 (2) ◽

pp. 326-347 ◽

Cited By ~ 46

Author(s):

Shouji Yamamoto ◽

Jiro Mitobe ◽

Takahiko Ishikawa ◽

Sun Nyunt Wai ◽

Makoto Ohnishi ◽

...

Keyword(s):

Sensor Kinase ◽

Two Component System ◽

Natural Competence ◽

Component System ◽

Two Component

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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

Journal of Bacteriology ◽

10.1128/jb.01524-09 ◽

2010 ◽

Vol 192 (8) ◽

pp. 2111-2127 ◽

Cited By ~ 71

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.

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Conformational Changes of an Interdomain Linker Mediate Mechanical Signal Transmission in Sensor Kinase BvgS

Journal of Bacteriology ◽

10.1128/jb.00114-17 ◽

2017 ◽

Vol 199 (18) ◽

Cited By ~ 5

Author(s):

Elodie Lesne ◽

Elian Dupré ◽

Camille Locht ◽

Rudy Antoine ◽

Françoise Jacob-Dubuisson

Keyword(s):

Signal Transduction ◽

Bordetella Pertussis ◽

Coiled Coil ◽

Protein Domain ◽

Sensor Kinase ◽

Two Component System ◽

Component System ◽

Content Type ◽

Two Component ◽

Sensor Kinases

ABSTRACT The whooping cough agent, Bordetella pertussis, controls the expression of its large virulence regulon in a coordinated manner through the two-component system BvgAS. BvgS is a dimeric, multidomain sensor kinase. Each monomer comprises, in succession, tandem periplasmic Venus flytrap (VFT) domains, a transmembrane segment, a cytoplasmic Per-Arnt-Sim (PAS) domain, a kinase module, and additional phosphorelay domains. BvgS shifts between kinase and phosphatase modes of activity in response to chemical modulators that modify the clamshell motions of the VFT domains. We have shown previously that this regulation involves a shift between distinct states of conformation and dynamics of the two-helix coiled-coil linker preceding the enzymatic module. In this work, we determined the mechanism of signal transduction across the membrane via a first linker, which connects the VFT and PAS domains of BvgS, using extensive cysteine cross-linking analyses and other approaches. Modulator perception by the periplasmic domains appears to trigger a small, symmetrical motion of the transmembrane segments toward the periplasm, causing rearrangements of the noncanonical cytoplasmic coiled coil that follows. As a consequence, the interface of the PAS domains is modified, which affects the second linker and eventually causes the shift of enzymatic activity. The major features of this first linker are well conserved among BvgS homologs, indicating that the mechanism of signal transduction unveiled here is likely to be generally relevant for this family of sensor kinases. IMPORTANCE Bordetella pertussis produces virulence factors coordinately regulated by the two-component system BvgAS. BvgS is a sensor kinase, and BvgA is a response regulator that activates gene transcription when phosphorylated by BvgS. Sensor kinases homologous to BvgS are also found in other pathogens. Our goal is to decipher the mechanisms of BvgS signaling, since these sensor kinases may represent new targets for antibacterial agents. Signal perception by the sensor domains of BvgS triggers small motions of the helical linker region underneath. The protein domain that follows this linker undergoes a large conformational change that amplifies the initial signal, causing a shift of activity from kinase to phosphatase. Because BvgS homologs harbor similar regions, these signaling mechanisms are likely to apply generally to that family of sensor kinases.

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A Two-Component System Plays an Important Role in the Root-Colonizing Ability of Pseudomonas fluorescens Strain WCS365

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1998.11.1.45 ◽

1998 ◽

Vol 11 (1) ◽

pp. 45-56 ◽

Cited By ~ 83

Author(s):

Linda C. Dekkers ◽

Cees Jan P. Bloemendaal ◽

Letty A. de Weger ◽

Carel A. Wijffelman ◽

Herman P. Spaink ◽

...

Keyword(s):

Pseudomonas Fluorescens ◽

Consensus Sequence ◽

Integration Host Factor ◽

Amino Acid Sequences ◽

Root Tip ◽

Sensor Kinase ◽

Two Component System ◽

Component System ◽

Wide Range ◽

Two Component

We describe the characterization of a novel Tn5lacZ colonization mutant of the efficiently colonizing Pseudomonas fluorescens strain WCS365, mutant strain PCL1210, which is at least 300- to 1,000-fold impaired in colonization of the potato root tip after co-inoculation of potato stem cuttings with a 1:1 mixture of mutant and parental cells. Similarly, the mutant is also impaired in colonization of tomato, wheat, and radish, indicating that the gene involved plays a role in the ability of P. fluorescens WCS365 to colonize a wide range of plant species. A 3.1-kb DNA fragment was found to be able to complement the observed mutation. The nucleotide sequence of the region around the Tn5lacZ insertion showed three open reading frames (ORFs). The transcriptional start site was determined. The operon is preceded by an integration host factor (IHF) binding site consensus sequence whereas no clear −10 and −35 sequences are present. The deduced amino acid sequences of the first two genes of the operon, designated as colR and colS, show strong similarity with known members of two-component regulatory systems. ColR has homology with the response regulators of the OmpR-PhoB subclass whereas ColS, the product of the gene in which the mutation resides, shows similarity to the sensor kinase members of these two-component systems. Hydrophobicity plots show that this hypothetical sensor kinase has two transmembrane domains, as is also known for other sensor kinases. The product of the third ORF, Orf222, shows no homology with known proteins. Only part of the orf222 gene is present in the colonization-complementing, 3.1-kb region, and it therefore does not play a role in complementation. No experimental evidence for a role of the ColR/ ColS two-component system in the suspected colonization traits chemotaxis and transport of exudate compounds could be obtained. The function of this novel two-component system therefore remains to be elucidated. We conclude that colonization is an active process in which an environmental stimulus, through this two-component system, activates a so far unknown trait that is crucial for colonization.

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PhoB transcriptional activator binds hierarchically to pho box promoters

Biological Chemistry ◽

10.1515/hsz-2012-0230 ◽

2012 ◽

Vol 393 (10) ◽

pp. 1165-1171 ◽

Cited By ~ 15

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.

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