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Dirr L, Cleeves S, Ramón Roth I, Li L, Fiebig T, Ve T, Häussler S, Braun A, von Itzstein M, Führing JI. Tetramerization is essential for the enzymatic function of the Pseudomonas aeruginosa virulence factor UDP-glucose pyrophosphorylase. mBio 2024; 15:e0211423. [PMID: 38470050 PMCID: PMC11005391 DOI: 10.1128/mbio.02114-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/20/2024] [Indexed: 03/13/2024] Open
Abstract
Multidrug-resistant bacteria such as the opportunistic pathogen Pseudomonas aeruginosa, which causes life-threatening infections especially in immunocompromised individuals and cystic fibrosis patients, pose an increasing threat to public health. In the search for new treatment options, P. aeruginosa uridine diphosphate-glucose pyrophosphorylase (PaUGP) has been proposed as a novel drug target because it is required for the biosynthesis of important virulence factors and linked to pathogenicity in animal models. Here, we show that UGP-deficient P. aeruginosa exhibits severely reduced virulence against human lung tissue and cells, emphasizing the enzyme's suitability as a drug target. To establish a basis for the development of selective PaUGP inhibitors, we solved the product-bound crystal structure of tetrameric PaUGP and conducted a comprehensive structure-function analysis, identifying key residues at two different molecular interfaces that are essential for tetramer integrity and catalytic activity and demonstrating that tetramerization is pivotal for PaUGP function. Importantly, we show that part of the PaUGP oligomerization interface is uniquely conserved across bacterial UGPs but does not exist in the human enzyme, therefore representing an allosteric site that may be targeted to selectively inhibit bacterial UGPs.IMPORTANCEInfections with the opportunistic bacterial pathogen Pseudomonas aeruginosa are becoming increasingly difficult to treat due to multidrug resistance. Here, we show that the enzyme uridine diphosphate-glucose pyrophosphorylase (UGP) is involved in P. aeruginosa virulence toward human lung tissue and cells, making it a potential target for the development of new antibacterial drugs. Our exploration of P. aeruginosa (Pa)UGP structure-function relationships reveals that the activity of PaUGP depends on the formation of a tetrameric enzyme complex. We found that a molecular interface involved in tetramer formation is conserved in all bacterial UGPs but not in the human enzyme, and therefore hypothesize that it provides an ideal point of attack to selectively inhibit bacterial UGPs and exploit them as drug targets.
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Affiliation(s)
- Larissa Dirr
- Institute for Glycomics, Gold Coast Campus, Griffith University, Gold Coast, Queensland, Australia
| | - Sven Cleeves
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research (DZL), Hannover, Germany
| | - Isabel Ramón Roth
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Linghui Li
- Institute for Glycomics, Gold Coast Campus, Griffith University, Gold Coast, Queensland, Australia
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Thomas Ve
- Institute for Glycomics, Gold Coast Campus, Griffith University, Gold Coast, Queensland, Australia
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover, Germany
- Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Armin Braun
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research (DZL), Hannover, Germany
- Institute of Immunology, Hannover Medical School, Hannover, Germany
| | - Mark von Itzstein
- Institute for Glycomics, Gold Coast Campus, Griffith University, Gold Coast, Queensland, Australia
| | - Jana I. Führing
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
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Fiebig T, Cramer JT, Bethe A, Baruch P, Curth U, Führing JI, Buettner FFR, Vogel U, Schubert M, Fedorov R, Mühlenhoff M. Structural and mechanistic basis of capsule O-acetylation in Neisseria meningitidis serogroup A. Nat Commun 2020; 11:4723. [PMID: 32948778 PMCID: PMC7501274 DOI: 10.1038/s41467-020-18464-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 08/20/2020] [Indexed: 02/08/2023] Open
Abstract
O-Acetylation of the capsular polysaccharide (CPS) of Neisseria meningitidis serogroup A (NmA) is critical for the induction of functional immune responses, making this modification mandatory for CPS-based anti-NmA vaccines. Using comprehensive NMR studies, we demonstrate that O-acetylation stabilizes the labile anomeric phosphodiester-linkages of the NmA-CPS and occurs in position C3 and C4 of the N-acetylmannosamine units due to enzymatic transfer and non-enzymatic ester migration, respectively. To shed light on the enzymatic transfer mechanism, we solved the crystal structure of the capsule O-acetyltransferase CsaC in its apo and acceptor-bound form and of the CsaC-H228A mutant as trapped acetyl-enzyme adduct in complex with CoA. Together with the results of a comprehensive mutagenesis study, the reported structures explain the strict regioselectivity of CsaC and provide insight into the catalytic mechanism, which relies on an unexpected Gln-extension of a classical Ser-His-Asp triad, embedded in an α/β-hydrolase fold.
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Affiliation(s)
- Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | | | - Andrea Bethe
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Petra Baruch
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Ute Curth
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Jana I Führing
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
- Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hannover, Germany
| | - Falk F R Buettner
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Ulrich Vogel
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Mario Schubert
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Roman Fedorov
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Martina Mühlenhoff
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
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Budde I, Litschko C, Führing JI, Gerardy-Schahn R, Schubert M, Fiebig T. An enzyme-based protocol for cell-free synthesis of nature-identical capsular oligosaccharides from Actinobacillus pleuropneumoniae serotype 1. J Biol Chem 2020; 295:5771-5784. [PMID: 32152227 PMCID: PMC7186170 DOI: 10.1074/jbc.ra120.012961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/09/2020] [Indexed: 11/06/2022] Open
Abstract
Actinobacillus pleuropneumoniae (App) is the etiological agent of acute porcine pneumonia and responsible for severe economic losses worldwide. The capsule polymer of App serotype 1 (App1) consists of [4)-GlcNAc-β(1,6)-Gal-α-1-(PO4-] repeating units that are O-acetylated at O-6 of the GlcNAc. It is a major virulence factor and was used in previous studies in the successful generation of an experimental glycoconjugate vaccine. However, the application of glycoconjugate vaccines in the animal health sector is limited, presumably because of the high costs associated with harvesting the polymer from pathogen culture. Consequently, here we exploited the capsule polymerase Cps1B of App1 as an in vitro synthesis tool and an alternative for capsule polymer provision. Cps1B consists of two catalytic domains, as well as a domain rich in tetratricopeptide repeats (TPRs). We compared the elongation mechanism of Cps1B with that of a ΔTPR truncation (Cps1B-ΔTPR). Interestingly, the product profiles displayed by Cps1B suggested processive elongation of the nascent polymer, whereas Cps1B-ΔTPR appeared to work in a more distributive manner. The dispersity of the synthesized products could be reduced by generating single-action transferases and immobilizing them on individual columns, separating the two catalytic activities. Furthermore, we identified the O-acetyltransferase Cps1D of App1 and used it to modify the polymers produced by Cps1B. Two-dimensional NMR analyses of the products revealed O-acetylation levels identical to those of polymer harvested from App1 culture supernatants. In conclusion, we have established a protocol for the pathogen-free in vitro synthesis of tailored, nature-identical App1 capsule polymers.
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Affiliation(s)
- Insa Budde
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg Strasse 1, 30625 Hannover, Germany
| | - Christa Litschko
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg Strasse 1, 30625 Hannover, Germany
| | - Jana I Führing
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg Strasse 1, 30625 Hannover, Germany; Fraunhofer International Consortium for Anti-Infective Research (iCAIR), 30625 Hannover, Germany
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg Strasse 1, 30625 Hannover, Germany; Fraunhofer International Consortium for Anti-Infective Research (iCAIR), 30625 Hannover, Germany
| | - Mario Schubert
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg Strasse 1, 30625 Hannover, Germany.
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Cramer JT, Führing JI, Baruch P, Brütting C, Knölker HJ, Gerardy-Schahn R, Fedorov R. Decoding Allosteric Networks in Biocatalysts: Rational Approach to Therapies and Biotechnologies. ACS Catal 2018. [DOI: 10.1021/acscatal.7b03714] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Johannes T. Cramer
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
- Institute for Biophysical Chemistry/Research Division for Structural Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Jana I. Führing
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Petra Baruch
- Institute for Biophysical Chemistry/Research Division for Structural Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Christian Brütting
- Department of Chemistry, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany
| | - Hans-Joachim Knölker
- Department of Chemistry, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Roman Fedorov
- Institute for Biophysical Chemistry/Research Division for Structural Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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