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Grundström, Christin
Publications (10 of 17) Show all publications
Krypotou, E., Scortti, M., Grundström, C., Oelker, M., Luisi, B. F., Sauer-Eriksson, A. E. & Vazquez-Boland, J. (2019). Control of Bacterial Virulence through the Peptide Signature of the Habitat. Cell reports, 26(7), 1815-1827
Open this publication in new window or tab >>Control of Bacterial Virulence through the Peptide Signature of the Habitat
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2019 (English)In: Cell reports, ISSN 2211-1247, E-ISSN 2211-1247, Vol. 26, no 7, p. 1815-1827Article in journal (Refereed) Published
Abstract [en]

To optimize fitness, pathogens selectively activate their virulence program upon host entry. Here, we report that the facultative intracellular bacterium Listeria monocytogenes exploits exogenous oligopeptides, a ubiquitous organic N source, to sense the environment and control the activity of its virulence transcriptional activator, PrfA. Using a genetic screen in adsorbent- treated ( PrfA-inducing) medium, we found that PrfA is functionally regulated by the balance between activating and inhibitory nutritional peptides scavenged via the Opp transport system. Activating peptides provide essential cysteine precursor for the PrfA-inducing cofactor glutathione ( GSH). Non-cysteine-containing peptides cause promiscuous PrfA inhibition. Biophysical and co-crystallization studies reveal that peptides inhibit PrfA through steric blockade of the GSH binding site, a regulation mechanism directly linking bacterial virulence and metabolism. L. monocytogenes mutant analysis in macrophages and our functional data support a model in which changes in the balance of antagonistic Oppimported oligopeptides promote PrfA induction intra-cellularly and PrfA repression outside the host.

Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-156873 (URN)10.1016/j.celrep.2019.01.073 (DOI)000458403600013 ()30759392 (PubMedID)
Available from: 2019-03-11 Created: 2019-03-11 Last updated: 2019-03-11Bibliographically approved
Rogne, P., Andersson, D., Grundström, C., Sauer-Eriksson, E., Linusson, A. & Wolf-Watz, M. (2019). Nucleation of an Activating Conformational Change by a Cation−Π Interaction. Biochemistry, 58(32), 3408-3412
Open this publication in new window or tab >>Nucleation of an Activating Conformational Change by a Cation−Π Interaction
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2019 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 58, no 32, p. 3408-3412Article in journal (Refereed) Published
Abstract [en]

As a key molecule in biology, adenosine triphosphate (ATP) has numerous crucial functions in, for instance, energetics, post-translational modifications, nucleotide biosynthesis, and cofactor metabolism. Here, we have discovered an intricate interplay between the enzyme adenylate kinase and its substrate ATP. The side chain of an arginine residue was found to be an efficient sensor of the aromatic moiety of ATP through the formation of a strong cation−π interaction. In addition to recognition, the interaction was found to have dual functionality. First, it nucleates the activating conformational transition of the ATP binding domain and also affects the specificity in the distant AMP binding domain. In light of the functional consequences resulting from the cation−π interaction, it is possible that the mode of ATP recognition may be a useful tool in enzyme design.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Organic Chemistry Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-162099 (URN)10.1021/acs.biochem.9b00538 (DOI)000480827100002 ()31339702 (PubMedID)
Available from: 2019-08-14 Created: 2019-08-14 Last updated: 2019-09-02Bibliographically approved
Zhang, J., Grundström, C., Brännström, K., Iakovleva, I., Lindberg, M. J., Olofsson, A., . . . Sauer-Eriksson, A. E. (2018). Interspecies variation between fish and human transthyretins in their binding of thyroid-disrupting chemicals. Environmental Science and Technology, 52(20), 11865-11874
Open this publication in new window or tab >>Interspecies variation between fish and human transthyretins in their binding of thyroid-disrupting chemicals
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2018 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 20, p. 11865-11874Article in journal (Refereed) Published
Abstract [en]

Thyroid-disrupting chemicals (TDCs) are xenobiotics that can interfere with the endocrine system and cause adverse effects in organisms and their offspring. TDCs affect both the thyroid gland and regulatory enzymes associated with thyroid hormone homeostasis. Transthyretin (TTR) is found in the serum and cerebrospinal fluid of vertebrates, where it transports thyroid hormones. Here, we explored the interspecies variation in TDC binding to human and fish TTR (exemplified by Gilthead seabream (Sparus aurata)). The in vitro binding experiments showed that TDCs bind with equal or weaker affinity to seabream TTR than to the human TTR, in particular, the polar TDCs (>500-fold lower affinity). Crystal structures of the seabream TTR TDC complexes revealed that all TDCs bound at the thyroid binding sites. However, amino acid substitution of Ser117 in human TTR to Thr117 in seabream prevented polar TDCs from binding deep in the hormone binding cavity, which explains their low affinity to seabream TTR Molecular dynamics and in silico alanine scanning simulation also suggested that the protein backbone of seabream TTR is more rigid than the human one and that Thr117 provides fewer electrostatic contributions than Ser117 to ligand binding. This provides an explanation for the weaker affinities of the ligands that rely on electrostatic interactions with Thr117. The lower affinities of TDCs to fish TTR, in particular the polar ones, could potentially lead to milder thyroid-related effects in fish.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-153704 (URN)10.1021/acs.est.8b03581 (DOI)000447816100046 ()30226982 (PubMedID)
Funder
Swedish Research Council Formas, 210-2012-131Swedish Research Council, 521-2011-6427Swedish Research Council, 2015-03607
Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2018-12-05Bibliographically approved
Rogne, P., Rosselin, M., Grundström, C., Hedberg, C., H. Sauer, U. & Wolf-Watz, M. (2018). Molecular mechanism of ATP versus GTP selectivity of adenylate kinase. Proceedings of the National Academy of Sciences of the United States of America, 115(12), 3012-3017
Open this publication in new window or tab >>Molecular mechanism of ATP versus GTP selectivity of adenylate kinase
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2018 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 12, p. 3012-3017Article in journal (Refereed) Published
Abstract [en]

Enzymatic substrate selectivity is critical for the precise control of metabolic pathways. In cases where chemically related substrates are present inside cells, robust mechanisms of substrate selectivity are required. Here, we report the mechanism utilized for catalytic ATP versus GTP selectivity during adenylate kinase (Adk) -mediated phosphorylation of AMP. Using NMR spectroscopy we found that while Adk adopts a catalytically competent and closed structural state in complex with ATP, the enzyme is arrested in a catalytically inhibited and open state in complex with GTP. X-ray crystallography experiments revealed that the interaction interfaces supporting ATP and GTP recognition, in part, are mediated by coinciding residues. The mechanism provides an atomic view on how the cellular GTP pool is protected from Adk turnover, which is important because GTP has many specialized cellular functions. In further support of this mechanism, a structure-function analysis enabled by synthesis of ATP analogs suggests that a hydrogen bond between the adenine moiety and the backbone of the enzyme is vital for ATP selectivity. The importance of the hydrogen bond for substrate selectivity is likely general given the conservation of its location and orientation across the family of eukaryotic protein kinases.

Keywords
adenylate kinase, selectivity, ATP, GTP, mechanism
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-145883 (URN)10.1073/pnas.1721508115 (DOI)000427829500063 ()29507216 (PubMedID)
Available from: 2018-03-20 Created: 2018-03-20 Last updated: 2018-06-09Bibliographically approved
Zetterström, C. E., Uusitalo, P., Qian, W., Hinch, S., Caraballo, R., Grundström, C. & Elofsson, M. (2018). Screening for Inhibitors of Acetaldehyde Dehydrogenase (AdhE) from Enterohemorrhagic Escherichia coli (EHEC). SLAS Discovery, 23(8), 815-822
Open this publication in new window or tab >>Screening for Inhibitors of Acetaldehyde Dehydrogenase (AdhE) from Enterohemorrhagic Escherichia coli (EHEC)
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2018 (English)In: SLAS Discovery, ISSN 2472-5552, Vol. 23, no 8, p. 815-822Article in journal (Refereed) Published
Abstract [en]

Acetaldehyde dehydrogenase (AdhE) is a bifunctional acetaldehyde-coenzyme A (CoA) dehydrogenase and alcohol dehydrogenase involved in anaerobic metabolism in gram-negative bacteria. This enzyme was recently found to be a key regulator of the type three secretion (T3S) system in Escherichia coli. AdhE inhibitors can be used as tools to study bacterial virulence and a starting point for discovery of novel antibacterial agents. We developed a robust enzymatic assay, based on the acetaldehyde-CoA dehydrogenase activity of AdhE using both absorption and fluorescence detection models (Z' > 0.7). This assay was used to screen similar to 11,000 small molecules in 384-well format that resulted in three hits that were confirmed by resynthesis and validation. All three compounds are noncompetitive with respect to acetaldehyde and display a clear dose-response effect with hill slopes of 1-2. These new inhibitors will be used as chemical tools to study the interplay between metabolism and virulence and the role of AdhE in T3S regulation in gram-negative bacteria, and as starting points for the development of novel antibacterial agents.

Place, publisher, year, edition, pages
Sage Publications, 2018
Keywords
EHEC, AdhE, screening, absorbance, fluorescence
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-151545 (URN)10.1177/2472555218768062 (DOI)000442275300005 ()29630847 (PubMedID)
Funder
Swedish Research Council
Available from: 2018-09-11 Created: 2018-09-11 Last updated: 2018-09-11Bibliographically approved
Kulén, M., Lindgren, M., Hansen, S., Cairns, A. G., Grundström, C., Begum, A., . . . Almqvist, F. (2018). Structure-based design of inhibitors targeting PrfA, the master virulence regulator of Listeria monocytogenes. Journal of Medicinal Chemistry, 61(9), 4165-4175
Open this publication in new window or tab >>Structure-based design of inhibitors targeting PrfA, the master virulence regulator of Listeria monocytogenes
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2018 (English)In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 61, no 9, p. 4165-4175Article in journal (Refereed) Published
Abstract [en]

Listeria monocytogenes is a bacterial pathogen that controls much of its virulence through the transcriptional regulator PrfA. In this study, we describe structure guided design and synthesis of a set of PrfA inhibitors based on ring-fused 2-pyridone heterocycles. Our most effective compound decreased virulence factor expression, reduced bacterial uptake into eukaryotic cells, and improved survival of chicken embryos infected with L. monocytogenes compared to previously identified compounds. Crystal structures identified an intraprotein "tunnel" as the main inhibitor binding site (A1), where the compounds participate in an extensive hydrophobic network that restricts the protein's ability to form functional DNA-binding helix−turn−helix (HTH) motifs. Our studies also revealed a hitherto unsuspected structural plasticity of the HTH motif. In conclusion, we have designed 2-pyridone analogues that function as site-A1 selective PrfA inhibitors with potent antivirulence properties.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Medicinal Chemistry
Identifiers
urn:nbn:se:umu:diva-148830 (URN)10.1021/acs.jmedchem.8b00289 (DOI)000432204800027 ()29667825 (PubMedID)2-s2.0-85046422455 (Scopus ID)
Available from: 2018-06-13 Created: 2018-06-13 Last updated: 2018-08-28Bibliographically approved
Kovermann, M., Grundström, C., Sauer-Eriksson, A. E., Sauer, U. H. & Wolf-Watz, M. (2017). Structural basis for ligand binding to an enzyme by a conformational selection pathway. Proceedings of the National Academy of Sciences of the United States of America, 114(24), 6298-6303
Open this publication in new window or tab >>Structural basis for ligand binding to an enzyme by a conformational selection pathway
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2017 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 114, no 24, p. 6298-6303Article in journal (Refereed) Published
Abstract [en]

Proteins can bind target molecules through either induced fit or conformational selection pathways. In the conformational selection model, a protein samples a scarcely populated high-energy state that resembles a target-bound conformation. In enzymatic catalysis, such high-energy states have been identified as crucial entities for activity and the dynamic interconversion between ground states and high-energy states can constitute the rate-limiting step for catalytic turnover. The transient nature of these states has precluded direct observation of their properties. Here, we present a molecular description of a high-energy enzyme state in a conformational selection pathway by an experimental strategy centered on NMR spectroscopy, protein engineering, and X-ray crystallography. Through the introduction of a disulfide bond, we succeeded in arresting the enzyme adenylate kinase in a closed high-energy conformation that is on-pathway for catalysis. A 1.9-angstrom X-ray structure of the arrested enzyme in complex with a transition state analog shows that catalytic side-chains are properly aligned for catalysis. We discovered that the structural sampling of the substrate free enzyme corresponds to the complete amplitude that is associated with formation of the closed and catalytically active state. In addition, we found that the trapped high-energy state displayed improved ligand binding affinity, compared with the wild-type enzyme, demonstrating that substrate binding to the high-energy state is not occluded by steric hindrance. Finally, we show that quenching of fast time scale motions observed upon ligand binding to adenylate kinase is dominated by enzyme-substrate interactions and not by intramolecular interactions resulting from the conformational change.

Place, publisher, year, edition, pages
National Academy of Sciences, 2017
Keywords
enzymatic catalysis, ligand binding, structural biology, adenylate kinase
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-137382 (URN)10.1073/pnas.1700919114 (DOI)000403179300051 ()28559350 (PubMedID)
Available from: 2017-07-06 Created: 2017-07-06 Last updated: 2018-06-09Bibliographically approved
Good, J. A. D., Andersson, C., Hansen, S., Wall, J., Krishnan, S., Begum, A., . . . Johansson, J. (2016). Attenuating Listeria monocytogenes virulence by targeting the regulatory protein PrfA. Cell chemical biology, 23(3), 404-414
Open this publication in new window or tab >>Attenuating Listeria monocytogenes virulence by targeting the regulatory protein PrfA
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2016 (English)In: Cell chemical biology, ISSN 2451-9448, Vol. 23, no 3, p. 404-414Article in journal (Refereed) Published
Abstract [en]

The transcriptional activator PrfA, a member of the Crp/Fnr family, controls the expression of some key virulence factors necessary for infection by the human bacterial pathogen Listeria monocytogenes. Phenotypic screening identified ring-fused 2-pyridone molecules that at low micromolar concentrations attenuate L. monocytogenes infectivity by reducing the expression of virulence genes, without compromising bacterial growth. These inhibitors bind the transcriptional regulator PrfA and decrease its affinity for the consensus DNA binding site. Structural characterization of this interaction revealed that one of the ring-fused 2-pyridones, compound 1, binds within a hydrophobic pocket, located between the C- and N-terminal domains of PrfA, and interacts with residues important for PrfA activation. This indicates that these inhibitors maintain the DNA-binding helix-turn-helix motif of PrfA in a disordered state, thereby preventing a PrfA:DNA interaction. Ring-fused 2-pyridones represent a new class of chemical probes for studying virulence in L. monocytogenes.

National Category
Biochemistry and Molecular Biology
Research subject
Molecular Biology
Identifiers
urn:nbn:se:umu:diva-114083 (URN)10.1016/j.chembiol.2016.02.013 (DOI)000381508300013 ()26991105 (PubMedID)
Note

Originally published in manuscipt form in thesis.

Available from: 2016-01-12 Created: 2016-01-12 Last updated: 2018-06-07Bibliographically approved
Hall, M., Grundström, C., Begum, A., Lindberg, M. J., Sauer, U. H., Almqvist, F., . . . Sauer-Eriksson, A. E. (2016). Structural basis for glutathione-mediated activation of the virulence regulatory protein PrfA in Listeria. Proceedings of the National Academy of Sciences of the United States of America, 113(51), 14733-14738
Open this publication in new window or tab >>Structural basis for glutathione-mediated activation of the virulence regulatory protein PrfA in Listeria
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2016 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 51, p. 14733-14738Article in journal (Refereed) Published
Abstract [en]

Infection by the human bacterial pathogen Listeria monocytogenes is mainly controlled by the positive regulatory factor A (PrfA), a member of the Crp/Fnr family of transcriptional activators. Published data suggest that PrfA requires the binding of a cofactor for full activity, and it was recently proposed that glutathione (GSH) could fulfill this function. Here we report the crystal structures of PrfA in complex with GSH and in complex with GSH and its cognate DNA, the hly operator PrfA box motif. These structures reveal the structural basis for a GSH-mediated allosteric mode of activation of PrfA in the cytosol of the host cell. The crystal structure of PrfAWT in complex only with DNA confirms that PrfAWT can adopt a DNA binding-compatible structure without binding the GSH activator molecule. By binding to PrfA in the cytosol of the host cell, GSH induces the correct fold of the HTH motifs, thus priming the PrfA protein for DNA interaction.

Keywords
Listeria, PrfA, activation, glutathione, virulence
National Category
Organic Chemistry Medical Genetics
Identifiers
urn:nbn:se:umu:diva-128915 (URN)10.1073/pnas.1614028114 (DOI)000390044900062 ()
Available from: 2016-12-19 Created: 2016-12-19 Last updated: 2018-06-09Bibliographically approved
Zhang, J., Begum, A., Brännström, K., Grundström, C., Iakovleva, I., Olofsson, A., . . . Andersson, P. L. (2016). Structure-based Virtual Screening Protocol for in silico Identification of Potential Thyroid Disrupting Chemicals Targeting Transthyretin. Environmental Science and Technology, 50(21), 11984-11993
Open this publication in new window or tab >>Structure-based Virtual Screening Protocol for in silico Identification of Potential Thyroid Disrupting Chemicals Targeting Transthyretin
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2016 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 21, p. 11984-11993Article in journal (Refereed) Published
Abstract [en]

Thyroid disruption by xenobiotics is associated with a broad spectrum of severe adverse outcomes. One possible molecular target of thyroid hormone disrupting chemicals (THDCs) is transthyretin (TTR), a thyroid hormone transporter in vertebrates. To better understand the interactions between TTR and THDCs, we determined the crystallographic structures of human TTR in complex with perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and 2,2',4,4'-tetrahydroxybenzophenone (BP2). The molecular interactions between the ligands and TTR were further characterized using molecular dynamics simulations. A structure-based virtual screening (VS) protocol was developed with the intention of providing an efficient tool for the discovery of novel TTR-binders from the Tox21 inventory. Among the 192 predicted binders, 12 representatives were selected, and their TTR binding affinities were studied with isothermal titration calorimetry, of which seven compounds had binding affinities between 0.26 and 100 mu M. To elucidate structural details in their binding to TTR, crystal structures were determined of TTR in complex with four of the identified compounds including 2,6-dinitro-p-cresol, bisphenol S, clonixin, and triclopyr. The compounds were found to bind in the TTR hormone binding sites as predicted. Our results show that the developed VS protocol is able to successfully identify potential THDCs, and we suggest that it can be used to propose THDCs for future toxicological evaluations.

National Category
Pharmacology and Toxicology Chemical Sciences
Identifiers
urn:nbn:se:umu:diva-125630 (URN)10.1021/acs.est.6b02771 (DOI)000386991100063 ()27668830 (PubMedID)
Available from: 2016-09-13 Created: 2016-09-13 Last updated: 2018-06-07Bibliographically approved
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