1
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Williams DE, Nesbitt NM, Muralidharan S, Hossain S, Boon EM. H-NOX Regulates Biofilm Formation in Agrobacterium Vitis in Response to NO. Biochemistry 2023; 62:912-922. [PMID: 36746768 DOI: 10.1021/acs.biochem.2c00639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transitions between motile and biofilm lifestyles are highly regulated and fundamental to microbial pathogenesis. H-NOX (heme-nitric oxide/oxygen-binding domain) is a key regulator of bacterial communal behaviors, such as biofilm formation. A predicted bifunctional cyclic di-GMP metabolizing enzyme, composed of diguanylate cyclase and phosphodiesterase (PDE) domains (avi_3097), is annotated downstream of an hnoX gene in Agrobacterium vitis S4. Here, we demonstrate that avH-NOX is a nitric oxide (NO)-binding hemoprotein that binds to and regulates the activity of avi_3097 (avHaCE; H-NOX-associated cyclic di-GMP processing enzyme). Kinetic analysis of avHaCE indicates a ∼four-fold increase in PDE activity in the presence of NO-bound avH-NOX. Biofilm analysis with crystal violet staining reveals that low concentrations of NO reduce biofilm growth in the wild-type A. vitis S4 strain, but the mutant ΔhnoX strain has no NO phenotype, suggesting that H-NOX is responsible for the NO biofilm phenotype in A. vitis. Together, these data indicate that avH-NOX enhances cyclic di-GMP degradation to reduce biofilm formation in response to NO in A. vitis.
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Affiliation(s)
- Dominique E Williams
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Natasha M Nesbitt
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sandhya Muralidharan
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sajjad Hossain
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Elizabeth M Boon
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
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2
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Wu G, Sharina I, Martin E. Soluble guanylyl cyclase: Molecular basis for ligand selectivity and action in vitro and in vivo. Front Mol Biosci 2022; 9:1007768. [PMID: 36304925 PMCID: PMC9592903 DOI: 10.3389/fmolb.2022.1007768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/27/2022] [Indexed: 01/14/2023] Open
Abstract
Nitric oxide (NO), carbon monoxide (CO), oxygen (O2), hydrogen sulfide (H2S) are gaseous molecules that play important roles in the physiology and pathophysiology of eukaryotes. Tissue concentrations of these physiologically relevant gases vary remarkable from nM range for NO to high μM range of O2. Various hemoproteins play a significant role in sensing and transducing cellular signals encoded by gaseous molecules or in transporting them. Soluble guanylyl cyclase (sGC) is a hemoprotein that plays vital roles in a wide range of physiological functions and combines the functions of gaseous sensor and signal transducer. sGC uniquely evolved to sense low non-toxic levels of NO and respond to elevated NO levels by increasing its catalytic ability to generate the secondary signaling messenger cyclic guanosine monophosphate (cGMP). This review discusses sGC's gaseous ligand selectivity and the molecular basis for sGC function as high-affinity and selectivity NO receptor. The effects of other gaseous molecules and small molecules of cellular origin on sGC's function are also discussed.
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Affiliation(s)
- Gang Wu
- Hematology-Oncology Division, Department of Internal Medicine, The University of Texas—McGovern Medical School, Houston, TX, United States,*Correspondence: Gang Wu, ; Emil Martin,
| | - Iraida Sharina
- Cardiology Division, Department of Internal Medicine, The University of Texas—McGovern Medical School, Houston, TX, United States
| | - Emil Martin
- Cardiology Division, Department of Internal Medicine, The University of Texas—McGovern Medical School, Houston, TX, United States,*Correspondence: Gang Wu, ; Emil Martin,
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3
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Rozza AM, Papp M, McFarlane NR, Harvey JN, Oláh J. The Mechanism of Biochemical NO‐Sensing: Insights from Computational Chemistry. Chemistry 2022; 28:e202200930. [PMID: 35670519 PMCID: PMC9542423 DOI: 10.1002/chem.202200930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Indexed: 11/22/2022]
Abstract
The binding of small gas molecules such as NO and CO plays a major role in the signaling routes of the human body. The sole NO‐receptor in humans is soluble guanylyl cyclase (sGC) – a histidine‐ligated heme protein, which, upon NO binding, activates a downstream signaling cascade. Impairment of NO‐signaling is linked, among others, to cardiovascular and inflammatory diseases. In the present work, we use a combination of theoretical tools such as MD simulations, high‐level quantum chemical calculations and hybrid QM/MM methods to address various aspects of NO binding and to elucidate the most likely reaction paths and the potential intermediates of the reaction. As a model system, the H‐NOX protein from Shewanella oneidensis (So H‐NOX) homologous to the NO‐binding domain of sGC is used. The signaling route is predicted to involve NO binding to form a six‐coordinate intermediate heme‐NO complex, followed by relatively facile His decoordination yielding a five‐coordinate adduct with NO on the distal side with possible isomerization to the proximal side through binding of a second NO and release of the first one. MD simulations show that the His sidechain can quite easily rotate outward into solvent, with this motion being accompanied in our simulations by shifts in helix positions that are consistent with this decoordination leading to significant conformational change in the protein.
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Affiliation(s)
- Ahmed M. Rozza
- Department of Inorganic and Analytical Chemistry Budapest University of Technology and Economics 1111 Budapest Műegyetem rakpart 3. Hungary
- Department of Biotechnology Faculty of Agriculture Al-Azhar University Cairo 11651 Egypt
| | - Marcell Papp
- Department of Inorganic and Analytical Chemistry Budapest University of Technology and Economics 1111 Budapest Műegyetem rakpart 3. Hungary
| | - Neil R. McFarlane
- Department of Chemistry KU Leuven 3001 Leuven Celestijnenlaan 200 f- box 2404 Belgium
| | - Jeremy N. Harvey
- Department of Chemistry KU Leuven 3001 Leuven Celestijnenlaan 200 f- box 2404 Belgium
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry Budapest University of Technology and Economics 1111 Budapest Műegyetem rakpart 3. Hungary
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4
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Lehnert N, Kim E, Dong HT, Harland JB, Hunt AP, Manickas EC, Oakley KM, Pham J, Reed GC, Alfaro VS. The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity. Chem Rev 2021; 121:14682-14905. [PMID: 34902255 DOI: 10.1021/acs.chemrev.1c00253] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Nitric oxide (NO) is an important signaling molecule that is involved in a wide range of physiological and pathological events in biology. Metal coordination chemistry, especially with iron, is at the heart of many biological transformations involving NO. A series of heme proteins, nitric oxide synthases (NOS), soluble guanylate cyclase (sGC), and nitrophorins, are responsible for the biosynthesis, sensing, and transport of NO. Alternatively, NO can be generated from nitrite by heme- and copper-containing nitrite reductases (NIRs). The NO-bearing small molecules such as nitrosothiols and dinitrosyl iron complexes (DNICs) can serve as an alternative vehicle for NO storage and transport. Once NO is formed, the rich reaction chemistry of NO leads to a wide variety of biological activities including reduction of NO by heme or non-heme iron-containing NO reductases and protein post-translational modifications by DNICs. Much of our understanding of the reactivity of metal sites in biology with NO and the mechanisms of these transformations has come from the elucidation of the geometric and electronic structures and chemical reactivity of synthetic model systems, in synergy with biochemical and biophysical studies on the relevant proteins themselves. This review focuses on recent advancements from studies on proteins and model complexes that not only have improved our understanding of the biological roles of NO but also have provided foundations for biomedical research and for bio-inspired catalyst design in energy science.
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Affiliation(s)
- Nicolai Lehnert
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Eunsuk Kim
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Hai T Dong
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jill B Harland
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Andrew P Hunt
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Elizabeth C Manickas
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Kady M Oakley
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - John Pham
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Garrett C Reed
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Victor Sosa Alfaro
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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5
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A new paradigm for gaseous ligand selectivity of hemoproteins highlighted by soluble guanylate cyclase. J Inorg Biochem 2020; 214:111267. [PMID: 33099233 DOI: 10.1016/j.jinorgbio.2020.111267] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/23/2020] [Accepted: 09/27/2020] [Indexed: 02/06/2023]
Abstract
Nitric oxide (NO), carbon monoxide (CO), and oxygen (O2) are important physiological messengers whose concentrations vary in a remarkable range, [NO] typically from nM to several μM while [O2] reaching to hundreds of μM. One of the machineries evolved in living organisms for gas sensing is sensor hemoproteins whose conformational change upon gas binding triggers downstream response cascades. The recently proposed "sliding scale rule" hypothesis provides a general interpretation for gaseous ligand selectivity of hemoproteins, identifying five factors that govern gaseous ligand selectivity. Hemoproteins have intrinsic selectivity for the three gases due to a neutral proximal histidine ligand while proximal strain of heme and distal steric hindrance indiscriminately adjust the affinity of these three gases for heme. On the other hand, multiple-step NO binding and distal hydrogen bond donor(s) specifically enhance affinity for NO and O2, respectively. The "sliding scale rule" hypothesis provides clear interpretation for dramatic selectivity for NO over O2 in soluble guanylate cyclase (sGC) which is an important example of sensor hemoproteins and plays vital roles in a wide range of physiological functions. The "sliding scale rule" hypothesis has so far been validated by all experimental data and it may guide future designs for heme-based gas sensors.
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6
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Rozza AM, Menyhárd DK, Oláh J. Gas Sensing by Bacterial H-NOX Proteins: An MD Study. Molecules 2020; 25:molecules25122882. [PMID: 32585836 PMCID: PMC7356049 DOI: 10.3390/molecules25122882] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 01/08/2023] Open
Abstract
Gas sensing is crucial for both prokaryotes and eukaryotes and is primarily performed by heme-based sensors, including H-NOX domains. These systems may provide a new, alternative mode for transporting gaseous molecules in higher organisms, but for the development of such systems, a detailed understanding of the ligand-binding properties is required. Here, we focused on ligand migration within the protein matrix: we performed molecular dynamics simulations on three bacterial (Ka, Ns and Cs) H-NOX proteins and studied the kinetics of CO, NO and O2 diffusion. We compared the response of the protein structure to the presence of ligands, diffusion rate constants, tunnel systems and storage pockets. We found that the rate constant for diffusion decreases in the O2 > NO > CO order in all proteins, and in the Ns > Ks > Cs order if single-gas is considered. Competition between gases seems to seriously influence the residential time of ligands spent in the distal pocket. The channel system is profoundly determined by the overall fold, but the sidechain pattern has a significant role in blocking certain channels by hydrophobic interactions between bulky groups, cation-π interactions or hydrogen bonding triads. The majority of storage pockets are determined by local sidechain composition, although certain functional cavities, such as the distal and proximal pockets are found in all systems. A major guideline for the design of gas transport systems is the need to chemically bind the gas molecule to the protein, possibly joining several proteins with several heme groups together.
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Affiliation(s)
- Ahmed M. Rozza
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology, Budapest Szent Gellért tér 4, H-1111 Budapest, Hungary;
- Department of Biotechnology, Faculty of Agriculture, Al-Azhar University, Cairo 11651, Egypt
| | - Dóra K. Menyhárd
- Laboratory of Structural Chemistry and Biology & MTA-ELTE Protein Modelling Research Group, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
- Correspondence: (D.K.M.); (J.O.)
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology, Budapest Szent Gellért tér 4, H-1111 Budapest, Hungary;
- Correspondence: (D.K.M.); (J.O.)
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7
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Négrerie M. Iron transitions during activation of allosteric heme proteins in cell signaling. Metallomics 2020; 11:868-893. [PMID: 30957812 DOI: 10.1039/c8mt00337h] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Allosteric heme proteins can fulfill a very large number of different functions thanks to the remarkable chemical versatility of heme through the entire living kingdom. Their efficacy resides in the ability of heme to transmit both iron coordination changes and iron redox state changes to the protein structure. Besides the properties of iron, proteins may impose a particular heme geometry leading to distortion, which allows selection or modulation of the electronic properties of heme. This review focusses on the mechanisms of allosteric protein activation triggered by heme coordination changes following diatomic binding to proteins as diverse as the human NO-receptor, cytochromes, NO-transporters and sensors, and a heme-activated potassium channel. It describes at the molecular level the chemical capabilities of heme to achieve very different tasks and emphasizes how the properties of heme are determined by the protein structure. Particularly, this reviews aims at giving an overview of the exquisite adaptability of heme, from bacteria to mammals.
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Affiliation(s)
- Michel Négrerie
- Laboratoire d'Optique et Biosciences, INSERM, CNRS, Ecole Polytechnique, 91120 Palaiseau, France.
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8
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Nisbett LM, Binnenkade L, Bacon B, Hossain S, Kotloski NJ, Brutinel ED, Hartmann R, Drescher K, Arora DP, Muralidharan S, Thormann KM, Gralnick JA, Boon EM. NosP Signaling Modulates the NO/H-NOX-Mediated Multicomponent c-Di-GMP Network and Biofilm Formation in Shewanella oneidensis. Biochemistry 2019; 58:4827-4841. [PMID: 31682418 PMCID: PMC7290162 DOI: 10.1021/acs.biochem.9b00706] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biofilms form when bacteria aggregate in a self-secreted exopolysaccharide matrix; they are resistant to antibiotics and implicated in disease. Nitric oxide (NO) is known to mediate biofilm formation in many bacteria via ligation to H-NOX (heme-NO/oxygen binding) domains. Most NO-responsive bacteria, however, lack H-NOX domain-containing proteins. We have identified another NO-sensing protein (NosP), which is predicted to be involved in two-component signaling and biofilm regulation in many species. Here, we demonstrate that NosP participates in the previously described H-NOX/NO-responsive multicomponent c-di-GMP signaling network in Shewanella oneidensis. Strains lacking either nosP or its co-cistronic kinase nahK (previously hnoS) produce immature biofilms, while hnoX and hnoK (kinase responsive to NO/H-NOX) mutants result in wild-type biofilm architecture. We demonstrate that NosP regulates the autophosphorylation activity of NahK as well as HnoK. HnoK and NahK have been shown to regulate three response regulators (HnoB, HnoC, and HnoD) that together comprise a NO-responsive multicomponent c-di-GMP signaling network. Here, we propose that NosP/NahK adds regulation on top of H-NOX/HnoK to modulate this c-di-GMP signaling network, and ultimately biofilm formation, by governing the flux of phosphate through both HnoK and NahK. In addition, it appears that NosP and H-NOX act to counter each other in a push-pull mechanism; NosP/NahK promotes biofilm formation through inhibition of H-NOX/HnoK signaling, which itself reduces the extent of biofilm formation. Addition of NO results in a reduction of c-di-GMP and biofilm formation, primarily through disinhibition of HnoK activity.
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Affiliation(s)
- Lisa-Marie Nisbett
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Lucas Binnenkade
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Giessen, D-35392 Giessen, Germany
| | - Bezalel Bacon
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sajjad Hossain
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Nicholas J. Kotloski
- Department of Plant and Microbial Biology, University of Minnesota—Twin Cities, St. Paul, Minnesota 55108, United States
| | - Evan D. Brutinel
- Department of Plant and Microbial Biology, University of Minnesota—Twin Cities, St. Paul, Minnesota 55108, United States
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, Renthof 6, 35032 Marburg, Germany
| | - Dhruv P. Arora
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sandhya Muralidharan
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Kai M. Thormann
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Giessen, D-35392 Giessen, Germany
| | - Jeffrey A. Gralnick
- Department of Plant and Microbial Biology, University of Minnesota—Twin Cities, St. Paul, Minnesota 55108, United States
| | - Elizabeth M. Boon
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11794-3400, United States
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
- Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York 11794-3400, United States
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9
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Horst BG, Stewart EM, Nazarian AA, Marletta MA. Characterization of a Carbon Monoxide-Activated Soluble Guanylate Cyclase from Chlamydomonas reinhardtii. Biochemistry 2019; 58:2250-2259. [DOI: 10.1021/acs.biochem.9b00190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Benjamin G. Horst
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Edna M. Stewart
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Aren A. Nazarian
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Michael A. Marletta
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, California 94720, United States
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10
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Guo Y, Marletta MA. Structural Insight into H‐NOX Gas Sensing and Cognate Signaling Protein Regulation. Chembiochem 2018; 20:7-19. [DOI: 10.1002/cbic.201800478] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Yirui Guo
- California Institute for Quantitative BiosciencesUniversity of California, Berkeley Berkeley, CA 94720 USA
| | - Michael A. Marletta
- California Institute for Quantitative BiosciencesUniversity of California, Berkeley Berkeley, CA 94720 USA
- Department of Molecular and Cell BiologyUniversity of California, Berkeley Berkeley, CA 94720 USA
- Department of ChemistryUniversity of California, Berkeley Berkeley, CA 94720 USA
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11
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Hespen CW, Bruegger JJ, Guo Y, Marletta MA. Native Alanine Substitution in the Glycine Hinge Modulates Conformational Flexibility of Heme Nitric Oxide/Oxygen (H-NOX) Sensing Proteins. ACS Chem Biol 2018; 13:1631-1639. [PMID: 29757599 DOI: 10.1021/acschembio.8b00248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Heme nitric oxide/oxygen sensing (H-NOX) domains are direct NO sensors that regulate a variety of biological functions in both bacteria and eukaryotes. Previous work on H-NOX proteins has shown that upon NO binding, a conformational change occurs along two glycine residues on adjacent helices (termed the glycine hinge). Despite the apparent importance of the glycine hinge, it is not fully conserved in all H-NOX domains. Several H-NOX sensors from the family Flavobacteriaceae contain a native alanine substitution in one of the hinge residues. In this work, the effect of the increased steric bulk within the Ala-Gly hinge on H-NOX function was investigated. The hinge in Kordia algicida OT-1 ( Ka H-NOX) is composed of A71 and G145. Ligand-binding properties and signaling function for this H-NOX were characterized. The variant A71G was designed to convert the hinge region of Ka H-NOX to the typical Gly-Gly motif. In activity assays with its cognate histidine kinase (HnoK), the wild type displayed increased signal specificity compared to A71G. Increasing titrations of unliganded A71G gradually inhibits HnoK autophosphorylation, while increasing titrations of unliganded wild type H-NOX does not inhibit HnoK. Crystal structures of both wild type and A71G Ka H-NOX were solved to 1.9 and 1.6 Å, respectively. Regions of H-NOX domains previously identified as involved in protein-protein interactions with HnoK display significantly higher b-factors in A71G compared to wild-type H-NOX. Both biochemical and structural data indicate that the hinge region controls overall conformational flexibility of the H-NOX, affecting NO complex formation and regulation of its HnoK.
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Affiliation(s)
- Charles W. Hespen
- QB3 Institute, University of California—Berkeley, 356 Stanley Hall, Berkeley, California 94720-3220, United States
| | - Joel J. Bruegger
- QB3 Institute, University of California—Berkeley, 356 Stanley Hall, Berkeley, California 94720-3220, United States
| | - Yirui Guo
- QB3 Institute, University of California—Berkeley, 356 Stanley Hall, Berkeley, California 94720-3220, United States
| | - Michael A. Marletta
- QB3 Institute, University of California—Berkeley, 356 Stanley Hall, Berkeley, California 94720-3220, United States
- Department of Chemistry, Department of Molecular and Cell Biology, QB3 Institute, University of California—Berkeley, 374B Stanley Hall, Berkeley, California 94720-3220, United States
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12
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Sömmer A, Behrends S. Methods to investigate structure and activation dynamics of GC-1/GC-2. Nitric Oxide 2018; 78:S1089-8603(17)30348-8. [PMID: 29705716 DOI: 10.1016/j.niox.2018.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 12/18/2022]
Abstract
Soluble guanylyl cyclase (sGC) is a heterodimeric enzyme consisting of one α and one β subunit. The α1β1 (GC-1) and α2β1 (GC-2) heterodimers are important for NO signaling in humans and catalyse the conversion from GTP to cGMP. Each sGC subunit consists of four domains. Several crystal structures of the isolated domains are available. However, crystals of full-length sGC have failed to materialise. In consequence, the detailed three dimensional structure of sGC remains unknown to date. Different techniques including stopped-flow spectroscopy, Förster-resonance energy transfer, direct fluorescence, analytical ultracentrifugation, chemical cross-linking, small-angle X-ray scattering, electron microscopy, hydrogen-deuterium exchange and protein thermal shift assays, were used to collect indirect information. Taken together, this circumstantial evidence from different groups brings forth a plausible model of sGC domain arrangement, spatial orientation and dynamic rearrangement upon activation. For analysis of the active conformation the stable binding mode of sGC activators has a significant methodological advantage over the transient, elusive, complex and highly concentration dependent effects of NO in many applications. The methods used and the results obtained are reviewed and discussed in this article.
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Affiliation(s)
- Anne Sömmer
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Braunschweig - Institute of Technology, Germany.
| | - Sönke Behrends
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Braunschweig - Institute of Technology, Germany.
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13
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Bindings of NO, CO, and O 2 to multifunctional globin type dehaloperoxidase follow the 'sliding scale rule'. Biochem J 2017; 474:3485-3498. [PMID: 28899945 DOI: 10.1042/bcj20170515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/06/2017] [Accepted: 09/12/2017] [Indexed: 01/09/2023]
Abstract
Dehaloperoxidase-hemoglobin (DHP), a multifunctional globin protein, not only functions as an oxygen carrier as typical globins such as myoglobin and hemoglobin, but also as a peroxidase, a mono- and dioxygenase, peroxygenase, and an oxidase. Kinetics of DHP binding to NO, CO, and O2 were characterized for wild-type DHP A and B and the H55D and H55V DHP A mutants using stopped-flow methods. All three gaseous ligands bind to DHP significantly more weakly than sperm whale myoglobin (SWMb). Both CO and NO bind to DHP in a one-step process to form a stable six-coordinate complex. Multiple-step NO binding is not observed in DHP, which is similar to observations in SWMb, but in contrast with many heme sensor proteins. The weak affinity of DHP for O2 is mainly due to a fast O2 dissociation rate, in accordance with a longer εN-Fe distance between the heme iron and distal histidine in DHP than that in Mb, and an open-distal pocket that permits ligand escape. Binding affinities in DHP show the same 3-4 orders separation between the pairs NO/CO and CO/O2, consistent with the 'sliding scale rule' hypothesis. Strong gaseous ligand discrimination by DHP is very different from that observed in typical peroxidases, which show poor gaseous ligand selectivity, correlating with a neutral proximal imidazole ligand rather than an imidazolate. The present study provides useful insights into the rationale for DHP to function both as mono-oxygenase and oxidase, and is the first example of a globin peroxidase shown to follow the 'sliding scale rule' hypothesis in gaseous ligand discrimination.
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