scholarly journals Crystal Structure of a Proteolytic Fragment of the Sensor Histidine Kinase NarQ

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 149 ◽  
Author(s):  
Ivan Gushchin ◽  
Igor Melnikov ◽  
Vitaly Polovinkin ◽  
Andrii Ishchenko ◽  
Valentin Gordeliy
Keyword(s):  
Histidine Kinase ◽  
Point Of View ◽  
Important Class ◽  
Structural Studies ◽  
Transmembrane Helices ◽  
Proteolytic Fragment ◽  
Sensor Histidine Kinase ◽  
Signaling Systems ◽  
Two Component ◽  
Structural Point

Two-component signaling systems (TCSs) are a large and important class of sensory systems in bacteria, archaea, and some eukaryotes, yet their mechanism of action is still not fully understood from the structural point of view. Many TCS receptors are elongated flexible proteins with transmembrane (TM) regions, and are difficult to work with. Consequently, truncated fragments of the receptors are often used in structural studies. However, it is not fully clear whether the structures of the fragments correspond well to their native structures in the context of full-length proteins. Recently, we crystallized a fragment of Escherichia coli nitrate/nitrite sensor histidine kinase, NarQ, encompassing the sensor, TM, and HAMP domains. Here we report that a smaller proteolytic fragment consisting of the sensor and TM domains can also be crystallized using the in meso approach. The structure of the fragment is similar to the previously determined one, with minor differences in the vicinity of the truncation site. The results show that the crystallization of such sensor–TM fragments can be accomplished and can provide information on the packing of transmembrane helices, albeit limited, and that the proteolysis may or may not be a problem during crystallization.

The sensor histidine kinase ArlS is necessary for Staphylococcus aureus to activate ArlR in response to nutrient availability

2021 ◽  
Author(s):  
Paola K. Párraga Solórzano ◽  
Angela C. Shupe ◽  
Thomas E. Kehl-Fie
Keyword(s):  
Staphylococcus Aureus ◽  
Recent Work ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Residual Activity ◽  
Opportunistic Pathogen ◽  
Glucose Limitation ◽  
Sensor Histidine Kinase ◽  
Two Component ◽  
Glucose Availability

Staphylococcus aureus is a versatile opportunistic pathogen whose success is driven by its ability to adapt to diverse environments and host-imposed stresses. Two-component signal transduction systems, such as ArlRS, often mediate these adaptations. Loss of ArlRS or the response regulator ArlR alone impairs the ability of S. aureus to respond to host-imposed manganese starvation and glucose limitation. As sensor histidine kinases and response regulators frequently work as pairs, it has been assumed that ArlS senses and activates ArlR in response to these stimuli. However, recent work suggests that the sensor histidine kinase GraS can also activate ArlR, calling the contribution of ArlS in responding to manganese and glucose availability into question. The current studies reveal that ArlS is necessary to activate ArlR in response to manganese sequestration by the host immune effector calprotectin and glucose limitation. Although the loss of ArlS does not completely eliminate ArlR activity, this response regulator is no longer responsive to manganese or glucose availability in the absence of its cognate histidine kinase. Despite the residual activity of ArlR in the absence of ArlS, ArlR phosphorylation by ArlS is required for S. aureus to resist calprotectin-imposed metal starvation. Cumulatively, these findings contribute to the understanding of S. aureus signaling transduction in response to nutritional immunity and support the previous observation that indicates ArlRS is activated by a common signal derived from host-imposed manganese and glucose limitation. IMPORTANCE The ability of pathogens, including Staphylococcus aureus , to sense and adapt to diverse environments partially relies on two-component systems, such as ArlRS. Recent work revealed that the response regulator ArlR can be cross-activated by the sensor histidine kinase GraS, rendering the role of its cognate partner, ArlS, in response to manganese and glucose limitation uncertain. This study reveals that ArlS is necessary for the activation of ArlR in response to calprotectin and glucose limitation. Although a low level of ArlR activity remains in the absence of ArlS, ArlS phosphotransfer to ArlR is required for S. aureus to overcome calprotectin-induced nutritional stress. Collectively, this study provides fundamental information to understand how ArlRS mediates staphylococcal adaptation during infection.

scholarly journals Molecular basis of unidirectional information transmission in two-component systems: lessons from the DesK-DesR thermosensor

2021 ◽  
Author(s):  
Sofia Lima ◽  
Juan Blanco ◽  
Federico Olivieri ◽  
Juan Andres Imelio ◽  
Federico Carrion ◽  
...  
Keyword(s):  
Histidine Kinase ◽  
Regulatory Networks ◽  
Response Regulator ◽  
Signal Transmission ◽  
Phosphoryl Transfer ◽  
Signaling Systems ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Histidine Phosphorylation

Cellular signaling systems transmit information over long distances using allosteric transitions and/or post-translational modifications. In two-component systems the sensor histidine kinase and response regulator are wired through phosphoryl-transfer reactions, using either a uni- or bi-directional transmission mode, allowing to build rich regulatory networks. Using the thermosensor DesK-DesR two-component system from Bacillus subtilis and combining crystal structures, QM/MM calculations and integrative kinetic modeling, we uncover that: i) longer or shorter distances between the phosphoryl-acceptor and -donor residues can shift the phosphoryl-transfer equilibrium; ii) the phosphorylation-dependent dimerization of the regulator acts as a sequestering mechanism by preventing the interaction with the histidine kinase; and iii) the kinase's intrinsic conformational equilibrium makes the phosphotransferase state unlikely in the absence of histidine phosphorylation, minimizing backwards transmission. These mechanisms allow the system to control the direction of signal transmission in a very efficient way, showcasing the key role that structure-encoded allostery plays in signaling proteins to store and transmit information.

scholarly journals Identification of a Two-Component Regulatory Pathway Essential for Mn(II) Oxidation in Pseudomonas putida GB-1

2009 ◽  
Vol 76 (4) ◽  
pp. 1224-1231 ◽  
Author(s):  
Kati Geszvain ◽  
Bradley M. Tebo
Keyword(s):  
Pseudomonas Putida ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Bacterial Species ◽  
Cosmid Library ◽  
Causative Mutation ◽  
Regulatory Pathway ◽  
Kinase Gene ◽  
Sensor Histidine Kinase ◽  
Two Component

ABSTRACT Bacterial manganese(II) oxidation has a profound impact on the biogeochemical cycling of Mn and the availability of the trace metals adsorbed to the surfaces of solid Mn(III, IV) oxides. The Mn(II) oxidase enzyme was tentatively identified in Pseudomonas putida GB-1 via transposon mutagenesis: the mutant strain GB-1-007, which fails to oxidize Mn(II), harbors a transposon insertion in the gene cumA. cumA encodes a putative multicopper oxidase (MCO), a class of enzymes implicated in Mn(II) oxidation in other bacterial species. However, we show here that an in-frame deletion of cumA did not affect Mn(II) oxidation. Through complementation analysis of the oxidation defect in GB-1-007 with a cosmid library and subsequent sequencing of candidate genes we show the causative mutation to be a frameshift within the mnxS1 gene that encodes a putative sensor histidine kinase. The frameshift mutation results in a truncated protein lacking the kinase domain. Multicopy expression of mnxS1 restored Mn(II) oxidation to GB-1-007 and in-frame deletion of mnxS1 resulted in a loss of oxidation in the wild-type strain. These results clearly demonstrated that the oxidation defect of GB-1-007 is due to disruption of mnxS1, not cumA::Tn5, and that CumA is not the Mn(II) oxidase. mnxS1 is located upstream of a second sensor histidine kinase gene, mnxS2, and a response regulator gene, mnxR. In-frame deletions of each of these genes also led to the loss of Mn(II) oxidation. Therefore, we conclude that the MnxS1/MnxS2/MnxR two-component regulatory pathway is essential for Mn(II) oxidation in P. putida GB-1.

scholarly journals Comparative analysis of two paradigm bacteriophytochromes reveals opposite functionalities in two-component signaling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elina Multamäki ◽  
Rahul Nanekar ◽  
Dmitry Morozov ◽  
Topias Lievonen ◽  
David Golonka ◽  
...  
Keyword(s):  
Histidine Kinase ◽  
Deinococcus Radiodurans ◽  
Response Regulator ◽  
Red Light ◽  
Kinase Domain ◽  
Structural Level ◽  
Signaling Systems ◽  
Two Component ◽  
Cognate Response Regulator ◽  
Absorbing States

AbstractBacterial phytochrome photoreceptors usually belong to two-component signaling systems which transmit environmental stimuli to a response regulator through a histidine kinase domain. Phytochromes switch between red light-absorbing and far-red light-absorbing states. Despite exhibiting extensive structural responses during this transition, the model bacteriophytochrome from Deinococcus radiodurans (DrBphP) lacks detectable kinase activity. Here, we resolve this long-standing conundrum by comparatively analyzing the interactions and output activities of DrBphP and a bacteriophytochrome from Agrobacterium fabrum (Agp1). Whereas Agp1 acts as a conventional histidine kinase, we identify DrBphP as a light-sensitive phosphatase. While Agp1 binds its cognate response regulator only transiently, DrBphP does so strongly, which is rationalized at the structural level. Our data pinpoint two key residues affecting the balance between kinase and phosphatase activities, which immediately bears on photoreception and two-component signaling. The opposing output activities in two highly similar bacteriophytochromes suggest the use of light-controllable histidine kinases and phosphatases for optogenetics.

scholarly journals Regulation of Resistance in Vancomycin-Resistant Enterococci: The VanRS Two-Component System

2021 ◽  
Vol 9 (10) ◽  
pp. 2026
Author(s):  
Alexandra A. Guffey ◽  
Patrick J. Loll
Keyword(s):  
Histidine Kinase ◽  
Response Regulator ◽  
Treatment Options ◽  
Vancomycin Resistance ◽  
Two Component System ◽  
Component System ◽  
Sensor Histidine Kinase ◽  
Vancomycin Resistant Enterococci ◽  
Two Component ◽  
Vancomycin Resistant

Vancomycin-resistant enterococci (VRE) are a serious threat to human health, with few treatment options being available. New therapeutics are urgently needed to relieve the health and economic burdens presented by VRE. A potential target for new therapeutics is the VanRS two-component system, which regulates the expression of vancomycin resistance in VRE. VanS is a sensor histidine kinase that detects vancomycin and in turn activates VanR; VanR is a response regulator that, when activated, directs expression of vancomycin-resistance genes. This review of VanRS examines how the expression of vancomycin resistance is regulated, and provides an update on one of the field’s most pressing questions: How does VanS sense vancomycin?

scholarly journals Extracytoplasmic PAS-Like Domains Are Common in Signal Transduction Proteins

2009 ◽  
Vol 192 (4) ◽  
pp. 1156-1159 ◽  
Author(s):  
Changsoo Chang ◽  
Christine Tesar ◽  
Minyi Gu ◽  
Gyorgy Babnigg ◽  
Andrzej Joachimiak ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Signal Transduction ◽  
Histidine Kinase ◽  
Pas Domain ◽  
Two Component System ◽  
Component System ◽  
Sensor Histidine Kinase ◽  
Two Component ◽  
Sensor Kinases ◽  
Signal Transduction Proteins

ABSTRACT We present the crystal structure of the extracytoplasmic domain of the Bacillus subtilis PhoR sensor histidine kinase, part of a two-component system involved in adaptation to low environmental phosphate concentrations. In addition to the PhoR structure, we predict that the majority of the extracytoplasmic domains of B. subtilis sensor kinases will adopt a fold similar to the ubiquitous PAS domain.

scholarly journals Illuminating a Phytochrome Paradigm – a Light-Activated Phosphatase in Two-Component Signaling Uncovered

2020 ◽  
Author(s):  
Elina Multamäki ◽  
Rahul Nanekar ◽  
Dmitry Morozov ◽  
Topias Lievonen ◽  
David Golonka ◽  
...  
Keyword(s):  
Histidine Kinase ◽  
Deinococcus Radiodurans ◽  
Response Regulator ◽  
Red Light ◽  
Kinase Domain ◽  
Structural Level ◽  
Signaling Systems ◽  
Two Component ◽  
Cognate Response Regulator ◽  
Absorbing States

ABSTRACTBacterial phytochrome photoreceptors usually belong to two-component signaling systems which transmit environmental stimuli to a response regulator through a histidine kinase domain. Phytochromes switch between red light-absorbing and far-red light-absorbing states. Despite exhibiting extensive structural responses during this transition, the model bacteriophytochrome from Deinococcus radiodurans (DrBphP) lacks detectable kinase activity. Here, we resolve this long-standing conundrum by comparatively analyzing the interactions and output activities of DrBphP and a bacteriophytochrome from Agrobacterium fabrum (AgP1). Whereas AgP1 acts as a conventional histidine kinase, we identify DrBphP as a light-sensitive phosphatase. While AgP1 binds its cognate response regulator only transiently, DrBphP does so strongly, which is rationalized at the structural level. Our data pinpoint two key residues affecting the balance between kinase and phosphatase activities, which immediately bears on photoreception and two-component signaling. The opposing output activities in two highly similar bacteriophytochromes inform the use of light-controllable histidine kinases and phosphatases for optogenetics.

scholarly journals Structural insights into the histidine-containing phosphotransfer protein and receiver domain of sensor histidine kinase suggest a complex model in the two-component regulatory system in Pseudomonas aeruginosa

IUCrJ ◽  
2020 ◽  
Vol 7 (5) ◽  
pp. 934-948
Author(s):  
Shao-Kang Chen ◽  
Hong-Hsiang Guan ◽  
Pei-Hsun Wu ◽  
Li-Ting Lin ◽  
Meng-Chun Wu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Active Site ◽  
Histidine Kinase ◽  
Convex Surface ◽  
Complex Model ◽  
Phosphoryl Group ◽  
Chronic Infections ◽  
Sensor Histidine Kinase ◽  
Receiver Domain ◽  
Two Component

In Pseudomonas aeruginosa, an important opportunistic pathogen that causes numerous acute and chronic infections, the hybrid two-component system (TCS) regulates the swarming ability and biofilm formation with a multistep phosphorelay, and consists of hybrid-sensor histidine kinase (HK), histidine-containing phosphotransfer protein (Hpt) and response regulator (RR). In this work, two crystal structures of HptB and the receiver domain of HK PA1611 (PA1611REC) of P. aeruginosa have been determined in order to elucidate their interactions for the transfer of the phosphoryl group. The structure of HptB folds into an elongated four-helix bundle – helices α2, α3, α4 and α5, covered by the short N-terminal helix α1. The imidazole side chain of the conserved active-site histidine residue His57, located near the middle of helix α3, protrudes from the bundle and is exposed to solvent. The structure of PA1611REC possesses a conventional (β/α)5 topology with five-stranded parallel β-sheets folded in the central region, surrounded by five α-helices. The divalent Mg2+ ion is located in the negatively charged active-site cleft and interacts with Asp522, Asp565 and Arg567. The HptB–PA1611REC complex is further modeled to analyze the binding surface and interactions between the two proteins. The model shows a shape complementarity between the convex surface of PA1611REC and the kidney-shaped HptB with fewer residues and a different network involved in interactions compared with other TCS complexes, such as SLN1-R1/YPD1 from Saccharomyces cerevisiae and AHK5RD/AHP1 from Arabidopsis thaliana. These structural results provide a better understanding of the TCS in P. aeruginosa and could potentially lead to the discovery of a new treatment for infection.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

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