1
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Schuelke-Sanchez A, Yennawar NH, Weinert EE. Oxygen-selective regulation of cyclic di-GMP synthesis by a globin coupled sensor with a shortened linking domain modulates Shewanella sp. ANA-3 biofilm. J Inorg Biochem 2024; 252:112482. [PMID: 38218138 DOI: 10.1016/j.jinorgbio.2024.112482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Bacteria utilize heme proteins, such as globin coupled sensors (GCSs), to sense and respond to oxygen levels. GCSs are predicted in almost 2000 bacterial species and consist of a globin domain linked by a central domain to a variety of output domains, including diguanylate cyclase domains that synthesize c-di-GMP, a major regulator of biofilm formation. To investigate the effects of middle domain length and heme edge residues on GCS diguanylate cyclase activity and cellular function, a putative diguanylate cyclase-containing GCS from Shewanella sp. ANA-3 (SA3GCS) was characterized. Binding of O2 to the heme resulted in activation of diguanylate cyclase activity, while NO and CO binding had minimal effects on catalysis, demonstrating that SA3GCS exhibits greater ligand selectivity for cyclase activation than many other diguanylate cyclase-containing GCSs. Small angle X-ray scattering analysis of dimeric SA3GCS identified movement of the cyclase domains away from each other, while maintaining the globin dimer interface, as a potential mechanism for regulating cyclase activity. Comparison of the Shewanella ANA-3 wild type and SA3GCS deletion (ΔSA3GCS) strains identified changes in biofilm formation, demonstrating that SA3GCS diguanylate cyclase activity modulates Shewanella phenotypes.
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Affiliation(s)
- Ariel Schuelke-Sanchez
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Emily E Weinert
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA; Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA.
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2
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Hoque NJ, Weinert EE. Control of bacterial second messenger signaling and motility by heme-based direct oxygen-sensing proteins. Curr Opin Microbiol 2023; 76:102396. [PMID: 37864983 DOI: 10.1016/j.mib.2023.102396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/23/2023]
Abstract
Bacteria sense and respond to their environment, allowing them to maximize their survival and growth under changing conditions, such as oxygen levels. Direct oxygen-sensing proteins allow bacteria to rapidly sense concentration changes and adapt by regulating signaling pathways and/or cellular machinery. Recent work has identified roles for direct oxygen-sensing proteins in controlling second messenger levels and motility machinery, as well as effects on biofilm formation, virulence, and motility. In this review, we discuss recent progress in understanding O2-dependent regulation of cyclic di-GMP signaling and motility and highlight the emerging importance in controlling bacterial physiology and behavior.
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Affiliation(s)
- Nushrat J Hoque
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Emily E Weinert
- Department of Chemistry, Penn State University, University Park, PA 16802, USA; Department of Biochemistry & Molecular Biology, Penn State University, University Park, PA 16802, USA.
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3
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Fekete FJ, Marotta NJ, Liu X, Weinert EE. An O 2-sensing diguanylate cyclase broadly affects the aerobic transcriptome in the phytopathogen Pectobacterium carotovorum. Front Microbiol 2023; 14:1134742. [PMID: 37485529 PMCID: PMC10360401 DOI: 10.3389/fmicb.2023.1134742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Pectobacterium carotovorum is an important plant pathogen responsible for the destruction of crops through bacterial soft rot, which is modulated by oxygen (O2) concentration. A soluble globin coupled sensor protein, Pcc DgcO (also referred to as PccGCS) is one way through which P. carotovorum senses oxygen. DgcO contains a diguanylate cyclase output domain producing c-di-GMP. Synthesis of the bacterial second messenger c-di-GMP is increased upon oxygen binding to the sensory globin domain. This work seeks to understand regulation of function by DgcO at the transcript level. RNA sequencing and differential expression analysis revealed that the deletion of DgcO only affects transcript levels in cells grown under aerobic conditions. Differential expression analysis showed that DgcO deletion alters transcript levels for metal transporters. These results, followed by inductively coupled plasma-mass spectrometry showing decreased concentrations of six biologically relevant metals upon DgcO deletion, provide evidence that a globin coupled sensor can affect cellular metal content. These findings improve the understanding of the transcript level control of O2-dependent phenotypes in an important phytopathogen and establish a basis for further studies on c-di-GMP-dependent functions in P. carotovorum.
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Affiliation(s)
- Florian J. Fekete
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
| | - Nick J. Marotta
- Graduate Program in Molecular, Cellular, and Integrative Biosciences, Penn State University, University Park, PA, United States
| | - Xuanyu Liu
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
| | - Emily E. Weinert
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
- Department of Chemistry, Penn State University, University Park, PA, United States
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4
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Hoque NJ, Helm MP, Weinert EE. In Vitro Measurement of Gas-Dependent and Redox-Sensitive Diguanylate Cyclase Activity. Methods Mol Biol 2023; 2648:75-86. [PMID: 37039986 DOI: 10.1007/978-1-0716-3080-8_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Bacteria sense and respond to gaseous ligand changes in the environment to regulate a multitude of behaviors, including the production of the secondary messengers cyclic di-GMP. Gas sensing can be difficult to measure due to the high concentration of the oxygen in the atmosphere, particularly in redox-sensitive systems. Here, we describe a method for anaerobic quantification of cyclic di-GMP production which can be used to measure the impact of molecular oxygen, nitric oxide, and carbon monoxide on the catalysis of a diguanylate cyclase-containing protein and the possible pitfalls in the experimental procedure.
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Affiliation(s)
- Nushrat J Hoque
- Department of Chemistry, Penn State University, University Park, PA, USA
| | - Madison P Helm
- Department of Chemistry, Penn State University, University Park, PA, USA
| | - Emily E Weinert
- Department of Chemistry, Penn State University, University Park, PA, USA.
- Department of Biochemistry & Molecular Biology, Penn State University, University Park, PA, USA.
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5
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Patterson DC, Weinert EE. Spectrophotometric Method for the Quantification and Kinetic Evaluation of In Vitro c-di-GMP Hydrolysis in the Presence and Absence of Oxygen. Methods Mol Biol 2023; 2648:87-98. [PMID: 37039987 DOI: 10.1007/978-1-0716-3080-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
A spectrophotometric method to measure hydrolysis of the bacterial second messenger cyclic dimeric guanosine monophosphate is described for characterization of enzymes under aerobic and anaerobic conditions. The method allows for obtaining all necessary data to calculate KM and kcat from reactions within a single 96-well plate that can be measured using a standard plate reader. The spectrophotometric assay has been used to measure the rates and obtain Michaelis-Menten parameters for the c-di-GMP phosphodiesterase DcpG with the sensor domain in various ligation states.
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Affiliation(s)
- Dayna C Patterson
- Department of Chemistry, Penn State University, University Park, PA, USA
| | - Emily E Weinert
- Department of Chemistry, Penn State University, University Park, PA, USA.
- Department of Biochemistry & Molecular Biology, Penn State University, University Park, PA, USA.
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6
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Snyder SN, Chiura T, Mak PJ. Resonance Raman Characterization of O 2-Binding Heme Proteins. Methods Mol Biol 2023; 2648:27-41. [PMID: 37039983 DOI: 10.1007/978-1-0716-3080-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
A vast array of critical in vivo processes and pathways are dependent on a multitude of O2-binding heme proteins which contain a diverse range of functions. Resonance Raman (rR) spectroscopy is an ideal technique for structural investigation of these proteins, providing information about the geometry of the Fe-O-O fragment and its electrostatic interactions with the distal active site. Characterization of these oxy adducts is an endeavor that is complicated by their instability for many heme proteins in solution, an obstacle which can be overcome by applying the rR technique to cryogenically frozen samples. We describe here how to measure rR spectra of heme proteins with stable oxy forms, as well as the technical adaptations required to measure unstable samples at 77 K.
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Affiliation(s)
- Samuel N Snyder
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA
| | - Tapiwa Chiura
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA
| | - Piotr J Mak
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA.
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7
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Dual Regulatory Role Exerted by Cyclic Dimeric GMP To Control FsnR-Mediated Bacterial Swimming. mBio 2022; 13:e0141422. [PMID: 36069448 DOI: 10.1128/mbio.01414-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial motility has great medical and ecological significance because of its essential role in bacterial survival and pathogenesis. Cyclic dimeric GMP (c-di-GMP), a second messenger in bacteria, is the predominant regulator of flagellar synthesis and motility and possesses turnover mechanisms that have been thoroughly investigated. Therefore, much attention has been focused on identifying the upstream stimulatory signals and downstream modules that respond to altered c-di-GMP levels. Here, we systematically analyzed c-di-GMP cyclases and phosphodiesterases in Stenotrophomonas maltophilia to screen for motility regulators. Of these enzymes, we identified and characterized a new phosphodiesterase named SisP, which was found to facilitate bacterial swimming upon stimulation with ferrous iron. SisP-mediated degradation of c-di-GMP leads to FsnR-dependent transcription of flagellar genes. Remarkably, c-di-GMP controls FsnR via two independent mechanisms: by direct binding and indirectly by modulating its phosphorylation state. In this study, we deciphered a novel "one stone, two birds" regulatory strategy of c-di-GMP and uncovered the signal that stimulates c-di-GMP hydrolysis. Facilitation of bacterial swimming motility by ferrous iron might contribute to the higher risk of bacterial infection in acutely ill patients. IMPORTANCE Stenotrophomonas maltophilia has become a great threat to human health because of the high mortality of infected patients. Swimming motility plays a crucial role in regulating bacterial virulence and adaptation. However, limited progress has been made in cyclic dimeric GMP (c-di-GMP) controlling swimming motility of S. maltophilia. Here, we characterized c-di-GMP turnover enzymes encoded by S. maltophilia and dissected the regulatory details of a phosphodiesterase named SisP. We demonstrated that SisP degrades c-di-GMP to fully activate FsnR through directly releasing FsnR from the FsnR-c-di-GMP complex and indirectly increasing its phosphorylation level. This finding uncovered a quantitative, rather than an on-off, regulatory manner employed by c-di-GMP to regulate activities of its effectors. Identification of the specific activation of SisP by ferrous iron proposes SisP as a putative drug-target for controlling bacterial infection and ferrous iron at the wounds or cuts as a putative factor contributing to the higher risk of bacterial infection.
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8
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Patterson DC, Liu Y, Das S, Yennawar NH, Armache JP, Kincaid JR, Weinert EE. Heme-Edge Residues Modulate Signal Transduction within a Bifunctional Homo-Dimeric Sensor Protein. Biochemistry 2021; 60:3801-3812. [PMID: 34843212 DOI: 10.1021/acs.biochem.1c00581] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bifunctional enzymes, which contain two domains with opposing enzymatic activities, are widely distributed in bacteria, but the regulatory mechanism(s) that prevent futile cycling are still poorly understood. The recently described bifunctional enzyme, DcpG, exhibits unusual heme properties and is surprisingly able to differentially regulate its two cyclic dimeric guanosine monophosphate (c-di-GMP) metabolic domains in response to heme gaseous ligands. Mutagenesis of heme-edge residues was used to probe the heme pocket and resulted in decreased O2 dissociation kinetics, identifying roles for these residues in modulating DcpG gas sensing. In addition, the resonance Raman spectra of the DcpG wild type and heme-edge mutants revealed that the mutations alter the heme electrostatic environment, vinyl group conformations, and spin state population. Using small-angle X-ray scattering and negative stain electron microscopy, the heme-edge mutations were demonstrated to cause changes to the protein conformation, which resulted in altered signaling transduction and enzyme kinetics. These findings provide insights into molecular interactions that regulate DcpG gas sensing as well as mechanisms that have evolved to control multidomain bacterial signaling proteins.
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Affiliation(s)
- Dayna C Patterson
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yilin Liu
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Sayan Das
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - James R Kincaid
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Emily E Weinert
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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9
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Abstract
Cyclic diguanylate (c-di-GMP) signal transduction systems provide bacteria with the ability to sense changing cell status or environmental conditions and then execute suitable physiological and social behaviors in response. In this review, we provide a comprehensive census of the stimuli and receptors that are linked to the modulation of intracellular c-di-GMP. Emerging evidence indicates that c-di-GMP networks sense light, surfaces, energy, redox potential, respiratory electron acceptors, temperature, and structurally diverse biotic and abiotic chemicals. Bioinformatic analysis of sensory domains in diguanylate cyclases and c-di-GMP-specific phosphodiesterases as well as the receptor complexes associated with them reveals that these functions are linked to a diverse repertoire of protein domain families. We describe the principles of stimulus perception learned from studying these modular sensory devices, illustrate how they are assembled in varied combinations with output domains, and summarize a system for classifying these sensor proteins based on their complexity. Biological information processing via c-di-GMP signal transduction not only is fundamental to bacterial survival in dynamic environments but also is being used to engineer gene expression circuitry and synthetic proteins with à la carte biochemical functionalities.
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10
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Patterson DC, Ruiz MP, Yoon H, Walker JA, Armache JP, Yennawar NH, Weinert EE. Differential ligand-selective control of opposing enzymatic activities within a bifunctional c-di-GMP enzyme. Proc Natl Acad Sci U S A 2021; 118:e2100657118. [PMID: 34475207 PMCID: PMC8433548 DOI: 10.1073/pnas.2100657118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/02/2021] [Indexed: 01/23/2023] Open
Abstract
Cyclic dimeric guanosine monophosphate (c-di-GMP) serves as a second messenger that modulates bacterial cellular processes, including biofilm formation. While proteins containing both c-di-GMP synthesizing (GGDEF) and c-di-GMP hydrolyzing (EAL) domains are widely predicted in bacterial genomes, it is poorly understood how domains with opposing enzymatic activity are regulated within a single polypeptide. Herein, we report the characterization of a globin-coupled sensor protein (GCS) from Paenibacillus dendritiformis (DcpG) with bifunctional c-di-GMP enzymatic activity. DcpG contains a regulatory sensor globin domain linked to diguanylate cyclase (GGDEF) and phosphodiesterase (EAL) domains that are differentially regulated by gas binding to the heme; GGDEF domain activity is activated by the Fe(II)-NO state of the globin domain, while EAL domain activity is activated by the Fe(II)-O2 state. The in vitro activity of DcpG is mimicked in vivo by the biofilm formation of P. dendritiformis in response to gaseous environment, with nitric oxide conditions leading to the greatest amount of biofilm formation. The ability of DcpG to differentially control GGDEF and EAL domain activity in response to ligand binding is likely due to the unusual properties of the globin domain, including rapid ligand dissociation rates and high midpoint potentials. Using structural information from small-angle X-ray scattering and negative stain electron microscopy studies, we developed a structural model of DcpG, providing information about the regulatory mechanism. These studies provide information about full-length GCS protein architecture and insight into the mechanism by which a single regulatory domain can selectively control output domains with opposing enzymatic activities.
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Affiliation(s)
- Dayna C Patterson
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Myrrh Perez Ruiz
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Hyerin Yoon
- Department of Chemistry, Emory University, Atlanta, GA 30322
| | | | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Emily E Weinert
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802;
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
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11
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Hammerschmid D, Germani F, Drusin SI, Fagnen C, Schuster CD, Hoogewijs D, Marti MA, Venien-Bryan C, Moens L, Van Doorslaer S, Sobott F, Dewilde S. Structural modeling of a novel membrane-bound globin-coupled sensor in Geobacter sulfurreducens. Comput Struct Biotechnol J 2021; 19:1874-1888. [PMID: 33995893 PMCID: PMC8076648 DOI: 10.1016/j.csbj.2021.03.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/24/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
Globin-coupled sensors (GCS) usually consist of three domains: a sensor/globin, a linker, and a transmitter domain. The globin domain (GD), activated by ligand binding and/or redox change, induces an intramolecular signal transduction resulting in a response of the transmitter domain. Depending on the nature of the transmitter domain, GCSs can have different activities and functions, including adenylate and di-guanylate cyclase, histidine kinase activity, aerotaxis and/or oxygen sensing function. The gram-negative delta-proteobacterium Geobacter sulfurreducens expresses a protein with a GD covalently linked to a four transmembrane domain, classified, by sequence similarity, as GCS (GsGCS). While its GD is fully characterized, not so its transmembrane domain, which is rarely found in the globin superfamily. In the present work, GsGCS was characterized spectroscopically and by native ion mobility-mass spectrometry in combination with cryo-electron microscopy. Although lacking high resolution, the oligomeric state and the electron density map were valuable for further rational modeling of the full-length GsGCS structure. This model demonstrates that GsGCS forms a transmembrane domain-driven tetramer with minimal contact between the GDs and with the heme groups oriented outward. This organization makes an intramolecular signal transduction less likely. Our results, including the auto-oxidation rate and redox potential, suggest a potential role for GsGCS as redox sensor or in a membrane-bound e-/H+ transfer. As such, GsGCS might act as a player in connecting energy production to the oxidation of organic compounds and metal reduction. Database searches indicate that GDs linked to a four or seven helices transmembrane domain occur more frequently than expected.
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Key Words
- AfGcHK, Anaeromyxobacter sp. Fw109-5 GcHK
- AsFRMF, Ascaris suum FRMF-amide receptor
- AvGReg, Azotobacter vinilandii Greg
- BpGReg, Bordetella pertussis Greg
- BsHemAT, Bacillus subtilis HemAT
- CCS, collision cross section
- CIU, collision-induced unfolding
- CMC, critical micelle concentration
- CV, cyclic voltammetry
- CeGLB26, Caenorhabditis elegans globin 26
- CeGLB33, Caenorhabditis elegans globin 33
- CeGLB6, Caenorhabditis elegans globin 6
- DDM, n-dodecyl-β-d-maltoside
- DPV, differential pulse voltammetry
- EcDosC, Escherichia coli Dos with DGC activity
- FMRF, H-Phe-Met-Arg-Phe-NH2 neuropeptide
- GCS, globin-coupled sensor
- GD, globin domain
- GGDEF, Gly-Gly-Asp-Glu-Phe motive
- Gb, globin
- Geobacter sulfurreducens
- GintHb, hemoglobin from Gasterophilus intestinalis
- Globin-coupled sensor
- GsGCS, Geobacter sulfurreducens GCS
- GsGCS162, GD of GsGCS
- IM-MS, ion mobility-mass spectrometry
- LmHemAC, Leishmania major HemAC
- MaPgb, Methanosarcina acetivorans protoglobin
- MtTrHbO, Mycobacterium tuberculosis truncated hemoglobin O
- NH4OAc, ammonium acetate
- OG, n-octyl-β-d-glucopyranoside
- PDE, phosphodiesterase
- PcMb, Physether catodon myoglobin
- PccGCS, Pectobacterium carotivorum GCS
- PsiE, phosphate-starvation-inducible E
- RR, resonance Raman
- SCE, saturated calomel electrode
- SHE, standard hydrogen electrode
- SaktrHb, Streptomyces avermitilis truncated hemoglobin-antibiotic monooxygenase
- SwMb, myoglobin from sperm whale
- TD, Transmitter domain
- TmD, Transmembrane domain
- Transmembrane domain
- Transmembrane-coupled globins
- mNgb, mouse neuroglobin
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Affiliation(s)
- Dietmar Hammerschmid
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Francesca Germani
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Salvador I. Drusin
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Charline Fagnen
- Sorbonne Université, UMR 7590, CNRS, Muséum National d’Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, IMPMC, 75005 Paris, France
| | - Claudio D. Schuster
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - David Hoogewijs
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, Switzerland
| | - Marcelo A. Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Catherine Venien-Bryan
- Sorbonne Université, UMR 7590, CNRS, Muséum National d’Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, IMPMC, 75005 Paris, France
| | - Luc Moens
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Sabine Van Doorslaer
- Biophysics and Biomedical Physics, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Frank Sobott
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, United Kingdom
| | - Sylvia Dewilde
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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12
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π-Helix controls activity of oxygen-sensing diguanylate cyclases. Biosci Rep 2021; 40:222070. [PMID: 32039439 PMCID: PMC7033309 DOI: 10.1042/bsr20193602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 11/18/2022] Open
Abstract
The ability of organisms to sense and adapt to oxygen levels in their environment leads to changes in cellular phenotypes, including biofilm formation and virulence. Globin coupled sensors (GCSs) are a family of heme proteins that regulate diverse functions in response to O2 levels, including modulating synthesis of cyclic dimeric guanosine monophosphate (c-di-GMP), a bacterial second messenger that regulates biofilm formation. While GCS proteins have been demonstrated to regulate O2-dependent pathways, the mechanism by which the O2 binding event is transmitted from the globin domain to the cyclase domain is unknown. Using chemical cross-linking and subsequent liquid chromatography-tandem mass spectrometry, diguanylate cyclase (DGC)-containing GCS proteins from Bordetella pertussis (BpeGReg) and Pectobacterium carotovorum (PccGCS) have been demonstrated to form direct interactions between the globin domain and a middle domain π-helix. Additionally, mutation of the π-helix caused major changes in oligomerization and loss of DGC activity. Furthermore, results from assays with isolated globin and DGC domains found that DGC activity is affected by the cognate globin domain, indicating unique interactions between output domain and cognate globin sensor. Based on these studies a compact GCS structure, which depends on the middle domain π-helix for orienting the three domains, is needed for DGC activity and allows for direct sensor domain interactions with both middle and output domains to transmit the O2 binding signal. The insights from the present study improve our understanding of DGC regulation and provide insight into GCS signaling that may lead to the ability to rationally control O2-dependent GCS activity.
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13
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Aline Dias da P, Nathalia Marins de A, Gabriel Guarany de A, Robson Francisco de S, Cristiane Rodrigues G. The World of Cyclic Dinucleotides in Bacterial Behavior. Molecules 2020; 25:molecules25102462. [PMID: 32466317 PMCID: PMC7288161 DOI: 10.3390/molecules25102462] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/05/2020] [Accepted: 03/17/2020] [Indexed: 02/07/2023] Open
Abstract
The regulation of multiple bacterial phenotypes was found to depend on different cyclic dinucleotides (CDNs) that constitute intracellular signaling second messenger systems. Most notably, c-di-GMP, along with proteins related to its synthesis, sensing, and degradation, was identified as playing a central role in the switching from biofilm to planktonic modes of growth. Recently, this research topic has been under expansion, with the discoveries of new CDNs, novel classes of CDN receptors, and the numerous functions regulated by these molecules. In this review, we comprehensively describe the three main bacterial enzymes involved in the synthesis of c-di-GMP, c-di-AMP, and cGAMP focusing on description of their three-dimensional structures and their structural similarities with other protein families, as well as the essential residues for catalysis. The diversity of CDN receptors is described in detail along with the residues important for the interaction with the ligand. Interestingly, genomic data strongly suggest that there is a tendency for bacterial cells to use both c-di-AMP and c-di-GMP signaling networks simultaneously, raising the question of whether there is crosstalk between different signaling systems. In summary, the large amount of sequence and structural data available allows a broad view of the complexity and the importance of these CDNs in the regulation of different bacterial behaviors. Nevertheless, how cells coordinate the different CDN signaling networks to ensure adaptation to changing environmental conditions is still open for much further exploration.
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14
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Germani F, Nardini M, De Schutter A, Cuypers B, Berghmans H, Van Hauwaert ML, Bruno S, Mozzarelli A, Moens L, Van Doorslaer S, Bolognesi M, Pesce A, Dewilde S. Structural and Functional Characterization of the Globin-Coupled Sensors of Azotobacter vinelandii and Bordetella pertussis. Antioxid Redox Signal 2020; 32:378-395. [PMID: 31559835 DOI: 10.1089/ars.2018.7690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aims: Structural and functional characterization of the globin-coupled sensors (GCSs) from Azotobacter vinelandii (AvGReg) and Bordetella pertussis (BpeGReg). Results: Ultraviolet/visible and resonance Raman spectroscopies confirm the presence in AvGReg and BpeGReg of a globin domain capable of reversible gaseous ligand binding. In AvGReg, an influence of the transmitter domain on the heme proximal region of the globin domain can be seen, and k'CO is higher than for other GCSs. The O2 binding kinetics suggests the presence of an open and a closed conformation. As for BpeGReg, the fully oxygenated AvGReg show a very high diguanylate cyclase activity. The carbon monoxide rebinding to BpeGReg indicates that intra- and intermolecular interactions influence the ligand binding. The globin domains of both proteins (AvGReg globin domain and BpeGRegGb with cysteines (Cys16, 45, 114, 154) mutated to serines [BpeGReg-Gb*]) share the same GCS fold, a similar proximal but a different distal side structure. They homodimerize through a G-H helical bundle as in other GCSs. However, BpeGReg-Gb* shows also a second dimerization mode. Innovation: This article extends our knowledge on the GCS proteins and contributes to a better understanding of the GCSs role in the formation of bacterial biofilms. Conclusions:AvGReg and BpeGReg conform to the GCS family, share a similar overall structure, but they have different properties in terms of the ligand binding. In particular, AvGReg shows an open and a closed conformation that in the latter form will very tightly bind oxygen. BpeGReg has only one closed conformation. In both proteins, it is the fully oxygenated GCS form that catalyzes the production of the second messenger.
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Affiliation(s)
- Francesca Germani
- Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Marco Nardini
- Department of Biosciences, University of Milano, Milano, Italy
| | - Amy De Schutter
- Department of Physics, University of Antwerp, Wilrijk, Belgium
| | - Bert Cuypers
- Department of Physics, University of Antwerp, Wilrijk, Belgium
| | - Herald Berghmans
- Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | | | - Stefano Bruno
- Department of Food and Drugs, University of Parma, Parma, Italy
| | | | - Luc Moens
- Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | | | | | | | - Sylvia Dewilde
- Department of Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
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15
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Skalova T, Lengalova A, Dohnalek J, Harlos K, Mihalcin P, Kolenko P, Stranava M, Blaha J, Shimizu T, Martínková M. Disruption of the dimerization interface of the sensing domain in the dimeric heme-based oxygen sensor AfGcHK abolishes bacterial signal transduction. J Biol Chem 2020; 295:1587-1597. [PMID: 31914416 PMCID: PMC7008379 DOI: 10.1074/jbc.ra119.011574] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/30/2019] [Indexed: 12/17/2022] Open
Abstract
The heme-based oxygen sensor protein AfGcHK is a globin-coupled histidine kinase in the soil bacterium Anaeromyxobacter sp. Fw109-5. Its C-terminal functional domain exhibits autophosphorylation activity induced by oxygen binding to the heme-Fe(II) complex located in the oxygen-sensing N-terminal globin domain. A detailed understanding of the signal transduction mechanisms in heme-containing sensor proteins remains elusive. Here, we investigated the role of the globin domain's dimerization interface in signal transduction in AfGcHK. We present a crystal structure of a monomeric imidazole-bound AfGcHK globin domain at 1.8 Å resolution, revealing that the helices of the WT globin dimer are under tension and suggesting that Tyr-15 plays a role in both this tension and the globin domain's dimerization. Biophysical experiments revealed that whereas the isolated WT globin domain is dimeric in solution, the Y15A and Y15G variants in which Tyr-15 is replaced with Ala or Gly, respectively, are monomeric. Additionally, we found that although the dimerization of the full-length protein is preserved via the kinase domain dimerization interface in all variants, full-length AfGcHK variants bearing the Y15A or Y15G substitutions lack enzymatic activity. The combined structural and biophysical results presented here indicate that Tyr-15 plays a key role in the dimerization of the globin domain of AfGcHK and that globin domain dimerization is essential for internal signal transduction and autophosphorylation in this protein. These findings provide critical insights into the signal transduction mechanism of the histidine kinase AfGcHK from Anaeromyxobacter.
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Affiliation(s)
- Tereza Skalova
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic
| | - Alzbeta Lengalova
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Jan Dohnalek
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic
| | - Karl Harlos
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom
| | - Peter Mihalcin
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Petr Kolenko
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic; FNSPE, Czech Technical University in Prague, Brehova 7, Prague 1, 115 19 Czech Republic
| | - Martin Stranava
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Jan Blaha
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Toru Shimizu
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Markéta Martínková
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic.
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16
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Lengalova A, Fojtikova-Proskova V, Vavra J, Martínek V, Stranava M, Shimizu T, Martinkova M. Kinetic analysis of a globin-coupled diguanylate cyclase, YddV: Effects of heme iron redox state, axial ligands, and heme distal mutations on catalysis. J Inorg Biochem 2019; 201:110833. [PMID: 31520879 DOI: 10.1016/j.jinorgbio.2019.110833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 12/19/2022]
Abstract
Heme-based oxygen sensors allow bacteria to regulate their activity based on local oxygen levels. YddV, a globin-coupled oxygen sensor with diguanylate cyclase activity from Escherichia coli, regulates cyclic-di-GMP synthesis based on oxygen availability. Stable and active samples of the full-length YddV protein were prepared by attaching it to maltose binding protein (MBP). To better understand the full-length protein's structure, the interactions between its domains were examined by performing a kinetic analysis. The diguanylate cyclase reaction catalyzed by YddV-MBP exhibited Michaelis-Menten kinetics. Its pH optimum was 8.5-9.0, and catalysis required either Mg2+ or Mn2+; other divalent metal ions gave no activity. The most active form of YddV-MBP had a 5-coordinate Fe(III) heme complex; its kinetic parameters were KmGTP 84 ± 21 μM and kcat 1.2 min-1. YddV-MBP with heme Fe(II), heme Fe(II)-O2, and heme Fe(II)-CO complexes had kcat values of 0.3 min-1, 0.95 min-1, and 0.3 min-1, respectively, suggesting that catalysis is regulated by the heme iron's redox state and axial ligand binding. The kcat values for heme Fe(III) complexes of L65G, L65Q, and Y43A YddV-MBP mutants bearing heme distal amino acid replacements were 0.15 min-1, 0.26 min-1 and 0.54 min-1, respectively, implying that heme distal residues play key regulatory roles by mediating signal transduction between the sensing and functional domains. Ultracentrifugation and size exclusion chromatography experiments showed that YddV-MBP is primarily dimeric in solution, with a sedimentation coefficient around 8. The inactive heme-free H93A mutant is primarily octameric, suggesting that catalytically active dimer formation requires heme binding.
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Affiliation(s)
- Alzbeta Lengalova
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Veronika Fojtikova-Proskova
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Jakub Vavra
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Václav Martínek
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Martin Stranava
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Toru Shimizu
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic
| | - Marketa Martinkova
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova (Albertov) 2030/8, Prague 2, Czech Republic.
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17
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Kuang S, Yuan Y, Wu Z, Peng R. Expression, purification and characterization of diguanylate cyclase from Rhodococcus ruber. Protein Expr Purif 2019; 163:105441. [PMID: 31195084 DOI: 10.1016/j.pep.2019.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/06/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022]
Abstract
Diguanylate cyclases (DGCs) were responsible for the synthesis of second messenger cyclic di-guanosine monophosphate (c-di-GMP), which were involved in various physiological activities of bacterial species. Here, a full-length DGC from Rhodococcus ruber SD3 fused with glutathione-S-transferase (GST) was expressed in E. coli and purified by glutathione agarose resin. The apparent molecular mass of one subunit of the purified diguanylate cyclase with GST tag (GST-DGC) was estimated to be 71.9 kDa by SDS-PAGE, which was approximately in accordance with the theoretical value of 73.0 kDa. The sequence of GST-DGC was confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The blue native PAGE indicated that GST-DGC formed octamer. The optimum pH and temperature for GST-DGC activity were 8.0 and 47 °C, respectively. The fusion protein exhibited high thermostability, and 94% of activity was retained when the protein was incubated at 87 °C for 1 h. Moreover, the fusion protein showed pH stability. The Km, Vmax and Kcat values for GST-DGC enzyme were 9.8 μM, 0.7 μM/min and 1.3 S-1. Some ions such as Zn2+, Mn2+, Fe2+, Ni2+ and Co2+ had inhibitory effects on the activity of the protein, while other ions such as Mg2+, K+ and Na+ slightly activated the protein. The fusion protein also showed rather high stability in the presence of toluene, cyclohexane and n-hexane.
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Affiliation(s)
- Sufang Kuang
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Yuan Yuan
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Zhonghao Wu
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Ren Peng
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China.
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18
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Hallberg ZF, Chan CH, Wright TA, Kranzusch PJ, Doxzen KW, Park JJ, Bond DR, Hammond MC. Structure and mechanism of a Hypr GGDEF enzyme that activates cGAMP signaling to control extracellular metal respiration. eLife 2019; 8:43959. [PMID: 30964001 PMCID: PMC6456294 DOI: 10.7554/elife.43959] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/12/2019] [Indexed: 12/16/2022] Open
Abstract
A newfound signaling pathway employs a GGDEF enzyme with unique activity compared to the majority of homologs associated with bacterial cyclic di-GMP signaling. This system provides a rare opportunity to study how signaling proteins natively gain distinct function. Using genetic knockouts, riboswitch reporters, and RNA-Seq, we show that GacA, the Hypr GGDEF in Geobacter sulfurreducens, specifically regulates cyclic GMP-AMP (3′,3′-cGAMP) levels in vivo to stimulate gene expression associated with metal reduction separate from electricity production. To reconcile these in vivo findings with prior in vitro results that showed GacA was promiscuous, we developed a full kinetic model combining experimental data and mathematical modeling to reveal mechanisms that contribute to in vivo specificity. A 1.4 Å-resolution crystal structure of the Geobacter Hypr GGDEF domain was determined to understand the molecular basis for those mechanisms, including key cross-dimer interactions. Together these results demonstrate that specific signaling can result from a promiscuous enzyme. Microscopic organisms known as bacteria are found in virtually every environment on the planet. One reason bacteria are so successful is that they are able to form communities known as biofilms on surfaces in animals and other living things, as well as on rocks and other features in the environment. These biofilms protect the bacteria from fluctuations in the environment and toxins. For over 30 years, a class of enzymes called the GGDEF enzymes were thought to make a single signal known as cyclic di-GMP that regulates the formation of biofilms. However, in 2016, a team of researchers reported that some GGDEF enzymes, including one from a bacterium called Geobacter sulfurreducens, were also able to produce two other signals known as cGAMP and cyclic di-AMP. The experiments involved making the enzymes and testing their activity outside the cell. Therefore, it remained unclear whether these enzymes (dubbed ‘Hypr’ GGDEF enzymes) actually produce all three signals inside cells and play a role in forming bacterial biofilms. G. sulfurreducens is unusual because it is able to grow on metallic minerals or electrodes to generate electrical energy. As part of a community of microorganisms, they help break down pollutants in contaminated areas and can generate electricity from wastewater. Now, Hallberg, Chan et al. – including many of the researchers involved in the 2016 work – combined several experimental and mathematical approaches to study the Hypr GGDEF enzymes in G. sulfurreducens. The experiments show that the Hypr GGDEF enzymes produced cGAMP, but not the other two signals, inside the cells. This cGAMP regulated the ability of G. sulfurreducens to grow by extracting electrical energy from the metallic minerals, which appears to be a new, biofilm-less lifestyle. Further experiments revealed how Hypr GGDEF enzymes have evolved to preferentially make cGAMP over the other two signals. Together, these findings demonstrate that enzymes with the ability to make several different signals, are capable of generating specific responses in bacterial cells. By understanding how bacteria make decisions, it may be possible to change their behaviors. The findings of Hallberg, Chan et al. help to identify the signaling pathways involved in this decision-making and provide new tools to study them in the future.
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Affiliation(s)
- Zachary F Hallberg
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Chi Ho Chan
- Department of Plant and Microbial Biology and BioTechnology Institute, University of Minnesota, Minnesota, United States
| | - Todd A Wright
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Philip J Kranzusch
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, United States.,Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, United States
| | - Kevin W Doxzen
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States
| | - James J Park
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Daniel R Bond
- Department of Plant and Microbial Biology and BioTechnology Institute, University of Minnesota, Minnesota, United States
| | - Ming C Hammond
- Department of Chemistry, University of California, Berkeley, Berkeley, United States.,Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, United States.,Department of Chemistry, University of Utah, Salt Lake City, United States
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19
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Lobão JBDS, Gondim ACS, Guimarães WG, Gilles‐Gonzalez M, Lopes LGDF, Sousa EHS. Oxygen triggers signal transduction in the DevS (DosS) sensor of
Mycobacterium tuberculosis
by modulating the quaternary structure. FEBS J 2019; 286:479-494. [DOI: 10.1111/febs.14734] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/05/2018] [Accepted: 12/14/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Josiane Bezerra da Silva Lobão
- Laboratory of Bioinorganic Chemistry Department of Organic and Inorganic Chemistry Federal University of Ceara Center for Sciences Fortaleza Brazil
| | - Ana C. S. Gondim
- Laboratory of Bioinorganic Chemistry Department of Organic and Inorganic Chemistry Federal University of Ceara Center for Sciences Fortaleza Brazil
| | - Wellinson G. Guimarães
- Laboratory of Bioinorganic Chemistry Department of Organic and Inorganic Chemistry Federal University of Ceara Center for Sciences Fortaleza Brazil
| | | | - Luiz Gonzaga de França Lopes
- Laboratory of Bioinorganic Chemistry Department of Organic and Inorganic Chemistry Federal University of Ceara Center for Sciences Fortaleza Brazil
| | - Eduardo H. S. Sousa
- Laboratory of Bioinorganic Chemistry Department of Organic and Inorganic Chemistry Federal University of Ceara Center for Sciences Fortaleza Brazil
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20
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Shimizu T, Lengalova A, Martínek V, Martínková M. Heme: emergent roles of heme in signal transduction, functional regulation and as catalytic centres. Chem Soc Rev 2019; 48:5624-5657. [DOI: 10.1039/c9cs00268e] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Molecular mechanisms of unprecedented functions of exchangeable/labile heme and heme proteins including transcription, DNA binding, protein kinase activity, K+ channel functions, cis–trans isomerization, N–N bond formation, and other functions are described.
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Affiliation(s)
- Toru Shimizu
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Alzbeta Lengalova
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Václav Martínek
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
| | - Markéta Martínková
- Department of Biochemistry
- Faculty of Science
- Charles University
- Prague 2
- Czech Republic
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21
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Rivera S, Young PG, Hoffer ED, Vansuch GE, Metzler CL, Dunham CM, Weinert EE. Structural Insights into Oxygen-Dependent Signal Transduction within Globin Coupled Sensors. Inorg Chem 2018; 57:14386-14395. [PMID: 30378421 DOI: 10.1021/acs.inorgchem.8b02584] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In order to respond to external stimuli, bacteria have evolved sensor proteins linking external signals to intracellular outputs that can then regulate downstream pathways and phenotypes. Globin coupled sensor proteins (GCSs) serve to link environmental O2 levels to cellular processes by coupling a heme-containing sensor globin domain to a catalytic output domain. However, the mechanism by which O2 binding activates these proteins is currently unknown. To provide insights into the signaling mechanism, two distinct dimeric complexes of the isolated globin domain of the GCS from Bordetella pertussis ( BpeGlobin) were solved via X-ray crystallography in which differences in ligand-bound states were observed. Both monomers of one dimer contain Fe(II)-O2 states, while the other dimer consists of the Fe(III)-H2O and Fe(II)-O2 states. These data provide the first molecular insights into the heme pocket conformation of the active Fe(II)-O2 form of these enzymes. In addition, heme distortion modes and heme-protein interactions were found to correlate with the ligation state of the globin, suggesting that these conformational changes play a role in O2-dependent signaling. Fourier transform infrared spectroscopy (FTIR) of the full-length GCS from B. pertussis ( BpeGReg) and the closely related GCS from Pectobacterium carotovorum ssp. carotovorum ( PccGCS) confirmed the importance of an ordered water within the heme pocket and two distal residues (Tyr43 and Ser68) as hydrogen-bond donors. Taken together, this work provides mechanistic insights into BpeGReg O2 sensing and the signaling mechanisms of diguanylate cyclase-containing GCS proteins.
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Affiliation(s)
- Shannon Rivera
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Paul G Young
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Eric D Hoffer
- Department of Biochemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Gregory E Vansuch
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Carmen L Metzler
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Christine M Dunham
- Department of Biochemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Emily E Weinert
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
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22
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Burns JL, Jariwala PB, Rivera S, Fontaine BM, Briggs L, Weinert EE. Oxygen-Dependent Globin Coupled Sensor Signaling Modulates Motility and Virulence of the Plant Pathogen Pectobacterium carotovorum. ACS Chem Biol 2017; 12:2070-2077. [PMID: 28612602 DOI: 10.1021/acschembio.7b00380] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial pathogens utilize numerous signals to identify the presence of their host and coordinate changes in gene expression that allow for infection. Within plant pathogens, these signals typically include small molecules and/or proteins from their plant hosts and bacterial quorum sensing molecules to ensure sufficient bacterial cell density for successful infection. In addition, bacteria use environmental signals to identify conditions when the host defenses are weakened and potentially to signal entry into an appropriate host/niche for infection. A globin coupled sensor protein (GCS), termed PccGCS, within the soft rot bacterium Pectobacterium carotovorum ssp. carotovorum WPP14 has been identified as an O2 sensor and demonstrated to alter virulence factor excretion and control motility, with deletion of PccGCS resulting in decreased rotting of a potato host. Using small molecules that modulate bacterial growth and quorum sensing, PccGCS signaling also has been shown to modulate quorum sensing pathways, resulting in the PccGCS deletion strain being more sensitive to plant-derived phenolic acids, which can function as quorum sensing inhibitors, and exhibiting increased N-acylhomoserine lactone (AHL) production. These findings highlight a role for GCS proteins in controlling key O2-dependent phenotypes of pathogenic bacteria and suggest that modulating GCS signaling to limit P. carotovorum motility may provide a means to decrease rotting of plant hosts.
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Affiliation(s)
- Justin L. Burns
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - Parth B. Jariwala
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - Shannon Rivera
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - Benjamin M. Fontaine
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - Laura Briggs
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
| | - Emily E. Weinert
- Department of Chemistry, Emory University, 1515
Dickey Drive, Atlanta, Georgia 30322, United States
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23
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Wan X, Saito JA, Newhouse JS, Hou S, Alam M. The importance of conserved amino acids in heme-based globin-coupled diguanylate cyclases. PLoS One 2017; 12:e0182782. [PMID: 28792538 PMCID: PMC5549716 DOI: 10.1371/journal.pone.0182782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/24/2017] [Indexed: 02/05/2023] Open
Abstract
Globin-coupled diguanylate cyclases contain globin, middle, and diguanylate cyclase domains that sense O2 to synthesize c-di-GMP and regulate bacterial motility, biofilm formation, and virulence. However, relatively few studies have extensively examined the roles of individual residues and domains of globin-coupled diguanylate cyclases, which can shed light on their signaling mechanisms and provide drug targets. Here, we report the critical residues of two globin-coupled diguanylate cyclases, EcGReg from Escherichia coli and BpeGReg from Bordetella pertussis, and show that their diguanylate cyclase activity requires an intact globin domain. In the distal heme pocket of the globin domain, residues Phe42, Tyr43, Ala68 (EcGReg)/Ser68 (BpeGReg), and Met69 are required to maintain full diguanylate cyclase activity. The highly conserved amino acids His223/His225 and Lys224/Lys226 in the middle domain of EcGReg/BpeGReg are essential to diguanylate cyclase activity. We also identified sixteen important residues (Leu300, Arg306, Asp333, Phe337, Lys338, Asn341, Asp342, Asp350, Leu353, Asp368, Arg372, Gly374, Gly375, Asp376, Glu377, and Phe378) in the active site and inhibitory site of the diguanylate cyclase domain of EcGReg. Moreover, BpeGReg266 (residues 1–266) and BpeGReg296 (residues 1–296), which only contain the globin and middle domains, can inhibit bacterial motility. Our findings suggest that the distal residues of the globin domain affect diguanylate cyclase activity and that BpeGReg may interact with other c-di-GMP-metabolizing proteins to form mixed signaling teams.
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Affiliation(s)
- Xuehua Wan
- Department of Microbiology, University of Hawaii, Honolulu, Hawaii, United States of America
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, Hawaii, United States of America
- * E-mail:
| | - Jennifer A. Saito
- Department of Microbiology, University of Hawaii, Honolulu, Hawaii, United States of America
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, Hawaii, United States of America
| | - James S. Newhouse
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Shaobin Hou
- Department of Microbiology, University of Hawaii, Honolulu, Hawaii, United States of America
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Maqsudul Alam
- Department of Microbiology, University of Hawaii, Honolulu, Hawaii, United States of America
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, Hawaii, United States of America
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24
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Abstract
The discovery of the globin-coupled sensor (GCS) family of haem proteins has provided new insights into signalling proteins and pathways by which organisms sense and respond to changing oxygen levels. GCS proteins consist of a sensor globin domain linked to a variety of output domains, suggesting roles in controlling numerous cellular pathways, and behaviours in response to changing oxygen concentration. Members of this family of proteins have been identified in the genomes of numerous organisms and characterization of GCS with output domains, including methyl accepting chemotaxis proteins, kinases, and diguanylate cyclases, have yielded an understanding of the mechanism by which oxygen controls activity of GCS protein output domains, as well as downstream proteins and pathways regulated by GCS signalling. Future studies will expand our understanding of these proteins both in vitro and in vivo, likely demonstrating broad roles for GCS in controlling oxygen-dependent microbial physiology and phenotypes.
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25
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Burns JL, Rivera S, Deer DD, Joynt SC, Dvorak D, Weinert EE. Oxygen and Bis(3',5')-cyclic Dimeric Guanosine Monophosphate Binding Control Oligomerization State Equilibria of Diguanylate Cyclase-Containing Globin Coupled Sensors. Biochemistry 2016; 55:6642-6651. [PMID: 27933792 DOI: 10.1021/acs.biochem.6b00526] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacteria sense their environment to alter phenotypes, including biofilm formation, to survive changing conditions. Heme proteins play important roles in sensing the bacterial gaseous environment and controlling the switch between motile and sessile (biofilm) states. Globin coupled sensors (GCS), a family of heme proteins consisting of a globin domain linked by a central domain to an output domain, are often found with diguanylate cyclase output domains that synthesize c-di-GMP, a major regulator of biofilm formation. Characterization of diguanylate cyclase-containing GCS proteins from Bordetella pertussis and Pectobacterium carotovorum demonstrated that cyclase activity is controlled by ligand binding to the heme within the globin domain. Both O2 binding to the heme within the globin domain and c-di-GMP binding to a product-binding inhibitory site (I-site) within the cyclase domain control oligomerization states of the enzymes. Changes in oligomerization state caused by c-di-GMP binding to the I-site also affect O2 kinetics within the globin domain, suggesting that shifting the oligomer equilibrium leads to broad rearrangements throughout the protein. In addition, mutations within the I-site that eliminate product inhibition result in changes to the accessible oligomerization states and decreased catalytic activity. These studies provide insight into the mechanism by which ligand binding to the heme and I-site controls activity of GCS proteins and suggests a role for oligomerization-dependent activity in vivo.
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Affiliation(s)
- Justin L Burns
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
| | - Shannon Rivera
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
| | - D Douglas Deer
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
| | - Shawnna C Joynt
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
| | - David Dvorak
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
| | - Emily E Weinert
- Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30307, United States
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26
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Zheng Y, Tsuji G, Opoku-Temeng C, Sintim HO. Inhibition of P. aeruginosa c-di-GMP phosphodiesterase RocR and swarming motility by a benzoisothiazolinone derivative. Chem Sci 2016; 7:6238-6244. [PMID: 30034764 PMCID: PMC6024209 DOI: 10.1039/c6sc02103d] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/15/2016] [Indexed: 01/18/2023] Open
Abstract
Various important cellular processes in bacteria are controlled by c-di-GMP, such as motility, biofilm formation and virulence factors production. C-di-GMP is synthesized from two molecules of GTP by diguanylate cyclases (DGCs) and its actions are terminated by EAL or HD-GYP domain phosphodiesterases (PDEs), which hydrolyze c-di-GMP to linear pGpG or GMP. Thus far the majority of efforts have been dedicated to the development of inhibitors of DGCs but not PDEs. This is probably because the old view was that inhibiting any c-di-GMP PDE would lead to biofilm formation, an undesirable phenotype. Recent data however suggest that some PDEs only change the localized (not global) concentration of c-di-GMP to increase bacterial virulence and do not affect biofilm formation. A challenge therefore is to be able to develop selective PDE inhibitors that inhibit virulence-associated PDEs but not inhibit PDEs that regulate bacterial biofilm formation. Using high throughput docking experiments to screen a library of 250 000 commercially available compounds against E. coli YahA (also called PdeL), a benzoisothiazolinone derivative was found to bind to the c-di-GMP binding site of YahA with favorable energetics. Paradoxically the in silico identified inhibitor (a benzoisothiazolinone derivative) did not inhibit the hydrolysis of c-di-GMP by YahA, the model PDE that was used in the docking, but instead inhibited RocR, which is a PDE from the opportunistic pathogen P. aeruginosa (PA). RocR promotes bacterial virulence but not biofilm dispersal, making it an ideal PDE to target for anti-virulence purposes. This newly identified RocR ligand displayed some selectivity and did not inhibit other P. aeruginosa PDEs, such as DipA, PvrR and PA4108. DipA, PvrR and PA4108 are key enzymes that reduce global c-di-GMP concentration and promote biofilm dispersal; therefore the identification of an inhibitor of a PA PDE, such as RocR, that does not inhibit major PDEs that modulate global c-di-GMP is an important step towards the development of selective c-di-GMP PDEs that could have interesting biomedical applications. The identified RocR ligand could also inhibit P. aeruginosa (PAO1) swarming but not swimming or biofilm formation. Rhamnolipid production was decreased, explaining the inhibition of swarming.
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Affiliation(s)
- Yue Zheng
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , IN 47907 , USA .
- Center for Drug Discovery , Purdue University , 720 Clinic Drive , West Lafayette , IN 47907 , USA
- Graduate Program in Biochemistry , University of Maryland , College Park , MD 20742 , USA
| | - Genichiro Tsuji
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , IN 47907 , USA .
- Center for Drug Discovery , Purdue University , 720 Clinic Drive , West Lafayette , IN 47907 , USA
| | - Clement Opoku-Temeng
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , IN 47907 , USA .
- Center for Drug Discovery , Purdue University , 720 Clinic Drive , West Lafayette , IN 47907 , USA
- Graduate Program in Biochemistry , University of Maryland , College Park , MD 20742 , USA
| | - Herman O Sintim
- Department of Chemistry , Purdue University , 560 Oval Drive , West Lafayette , IN 47907 , USA .
- Center for Drug Discovery , Purdue University , 720 Clinic Drive , West Lafayette , IN 47907 , USA
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27
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Rivera S, Burns JL, Vansuch GE, Chica B, Weinert EE. Globin domain interactions control heme pocket conformation and oligomerization of globin coupled sensors. J Inorg Biochem 2016; 164:70-76. [PMID: 27614715 DOI: 10.1016/j.jinorgbio.2016.08.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 08/24/2016] [Accepted: 08/26/2016] [Indexed: 12/24/2022]
Abstract
Globin coupled sensors (GCS) are O2-sensing proteins used by bacteria to monitor the surrounding gaseous environment. To investigate the biphasic O2 dissociation kinetics observed for full-length GCS proteins, isolated globin domains from Pectobacterium carotovorum ssp. carotovorum (PccGlobin), and Bordetella pertussis (BpeGlobin), have been characterized. PccGlobin is found to be dimeric, while BpeGlobin is monomeric, indicating key differences in the globin domain dimer interface. Through characterization of wild type globin domains and globin variants with mutations at the dimer interface and within the distal pocket, dimerization of the globin domain is demonstrated to correlate with biphasic dissociation kinetics. Furthermore, a distal pocket tyrosine is identified as the primary hydrogen bond donor, while a secondary hydrogen bond donor within the distal heme pocket is involved in conformation(s) that lead to the second O2 dissociation rate. These findings highlight the role of the globin dimer interface in controlling properties of both the heme pocket and full-length GCS proteins.
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Affiliation(s)
- Shannon Rivera
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 USA
| | - Justin L Burns
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 USA
| | - Gregory E Vansuch
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 USA
| | - Bryant Chica
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 USA
| | - Emily E Weinert
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 USA.
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28
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Schirmer T. C-di-GMP Synthesis: Structural Aspects of Evolution, Catalysis and Regulation. J Mol Biol 2016; 428:3683-701. [PMID: 27498163 DOI: 10.1016/j.jmb.2016.07.023] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 07/30/2016] [Accepted: 07/31/2016] [Indexed: 10/21/2022]
Abstract
Cellular levels of the second messenger cyclic di-guanosine monophosphate (c-di-GMP) are determined by the antagonistic activities of diguanylate cyclases and specific phosphodiesterases. In a given bacterial organism, there are often multiple variants of the two enzymes, which are tightly regulated by a variety of external and internal cues due to the presence of specialized sensory or regulatory domains. Dependent on the second messenger level, specific c-di-GMP receptors then control fundamental cellular processes, such as bacterial life style, biofilm formation, and cell cycle control. Here, I review the large body of data on structure-function relationships in diguanylate cyclases. Although the catalytic GGDEF domain is related to the respective domain of adenylate cyclases, the catalyzed intermolecular condensation reaction of two GTP molecules requires the formation of a competent GGDEF dimer with the two substrate molecules juxtaposed. This prerequisite appears to constitute the basis for GGDEF regulation with signal-induced changes within the homotypic dimer of the input domain (PAS, GAF, HAMP, etc.), which are structurally coupled with the arrangement of the GGDEF domains via a rigid coiled-coil linker. Alternatively, phosphorylation of a Rec input domain can drive GGDEF dimerization. Both mechanisms allow modular combination of input and output function that appears advantageous for evolution and rationalizes the striking similarities in domain architecture found in diguanylate cyclases and histidine kinases.
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Affiliation(s)
- Tilman Schirmer
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
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29
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An O2-sensing stressosome from a Gram-negative bacterium. Nat Commun 2016; 7:12381. [PMID: 27488264 PMCID: PMC4976288 DOI: 10.1038/ncomms12381] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/28/2016] [Indexed: 12/16/2022] Open
Abstract
Bacteria have evolved numerous pathways to sense and respond to changing environmental conditions, including, within Gram-positive bacteria, the stressosome complex that regulates transcription of general stress response genes. However, the signalling molecules recognized by Gram-positive stressosomes have yet to be identified, hindering our understanding of the signal transduction mechanism within the complex. Furthermore, an analogous pathway has yet to be described in Gram-negative bacteria. Here we characterize a putative stressosome from the Gram-negative bacterium Vibrio brasiliensis. The sensor protein RsbR binds haem and exhibits ligand-dependent control of the stressosome complex activity. Oxygen binding to the haem decreases activity, while ferrous RsbR results in increased activity, suggesting that the V. brasiliensis stressosome may be activated when the bacterium enters anaerobic growth conditions. The findings provide a model system for investigating ligand-dependent signalling within stressosome complexes, as well as insights into potential pathways controlled by oxygen-dependent signalling within Vibrio species.
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30
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Microbial Surface Colonization and Biofilm Development in Marine Environments. Microbiol Mol Biol Rev 2015; 80:91-138. [PMID: 26700108 DOI: 10.1128/mmbr.00037-15] [Citation(s) in RCA: 462] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Biotic and abiotic surfaces in marine waters are rapidly colonized by microorganisms. Surface colonization and subsequent biofilm formation and development provide numerous advantages to these organisms and support critical ecological and biogeochemical functions in the changing marine environment. Microbial surface association also contributes to deleterious effects such as biofouling, biocorrosion, and the persistence and transmission of harmful or pathogenic microorganisms and their genetic determinants. The processes and mechanisms of colonization as well as key players among the surface-associated microbiota have been studied for several decades. Accumulating evidence indicates that specific cell-surface, cell-cell, and interpopulation interactions shape the composition, structure, spatiotemporal dynamics, and functions of surface-associated microbial communities. Several key microbial processes and mechanisms, including (i) surface, population, and community sensing and signaling, (ii) intraspecies and interspecies communication and interaction, and (iii) the regulatory balance between cooperation and competition, have been identified as critical for the microbial surface association lifestyle. In this review, recent progress in the study of marine microbial surface colonization and biofilm development is synthesized and discussed. Major gaps in our knowledge remain. We pose questions for targeted investigation of surface-specific community-level microbial features, answers to which would advance our understanding of surface-associated microbial community ecology and the biogeochemical functions of these communities at levels from molecular mechanistic details through systems biological integration.
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31
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Tarnawski M, Barends TRM, Schlichting I. Structural analysis of an oxygen-regulated diguanylate cyclase. ACTA ACUST UNITED AC 2015; 71:2158-77. [PMID: 26527135 DOI: 10.1107/s139900471501545x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/18/2015] [Indexed: 11/10/2022]
Abstract
Cyclic di-GMP is a bacterial second messenger that is involved in switching between motile and sessile lifestyles. Given the medical importance of biofilm formation, there has been increasing interest in understanding the synthesis and degradation of cyclic di-GMPs and their regulation in various bacterial pathogens. Environmental cues are detected by sensing domains coupled to GGDEF and EAL or HD-GYP domains that have diguanylate cyclase and phosphodiesterase activities, respectively, producing and degrading cyclic di-GMP. The Escherichia coli protein DosC (also known as YddV) consists of an oxygen-sensing domain belonging to the class of globin sensors that is coupled to a C-terminal GGDEF domain via a previously uncharacterized middle domain. DosC is one of the most strongly expressed GGDEF proteins in E. coli, but to date structural information on this and related proteins is scarce. Here, the high-resolution structural characterization of the oxygen-sensing globin domain, the middle domain and the catalytic GGDEF domain in apo and substrate-bound forms is described. The structural changes between the iron(III) and iron(II) forms of the sensor globin domain suggest a mechanism for oxygen-dependent regulation. The structural information on the individual domains is combined into a model of the dimeric DosC holoprotein. These findings have direct implications for the oxygen-dependent regulation of the activity of the cyclase domain.
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Affiliation(s)
- Miroslaw Tarnawski
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Thomas R M Barends
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Ilme Schlichting
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
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