1
|
Kumar V, Boorman J, Greenlee WJ, Zeng X, Lin J, van den Akker F. Exploring the inhibition of the soluble lytic transglycosylase Cj0843c of Campylobacter jejuni via targeting different sites with different scaffolds. Protein Sci 2023:e4683. [PMID: 37209283 DOI: 10.1002/pro.4683] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/04/2023] [Accepted: 05/14/2023] [Indexed: 05/22/2023]
Abstract
Bacterial lytic transglycosylases (LTs) contribute to peptidoglycan cell wall metabolism and are potential drug targets to potentiate β-lactam antibiotics to overcome antibiotic resistance. Since LT inhibitor development is underexplored, we probed fifteen N-acetyl-containing heterocycles in a structure-guided fashion for their ability to inhibit and bind to the Campylobacter jejuni LT Cj0843c. Ten GlcNAc analogs were synthesized with substitutions at the C1 position, with two having an additional modification at the C4 or C6 position. Most of the compounds showed weak inhibition of Cj0843c activity. Compounds with alterations at the C4 position, replacing the -OH with a -NH2 , and C6 position, the addition of a -CH3 , yielded improved inhibitory efficacy. All ten GlcNAc analogs were crystallographically analyzed via soaking experiments using Cj0843c crystals and found to bind to the +1 +2 saccharide subsites with one of them additionally binding to the -2 -1 subsite region. We also probed other N-acetyl-containing heterocycles and found that sialidase inhibitors N-acetyl-2,3-dehydro-2-deoxyneuraminic acid and siastatin B inhibited Cj0843c weakly and crystallographically bound to the -2 -1 subsites. Analogs of the former also showed inhibition and crystallographic binding and included zanamivir amine. This latter set of heterocycles positioned their N-acetyl group in the -2 subsite with additional moieties interacting in the -1 subsite. Overall, these results could provide novel opportunities for LT inhibition via exploring different subsites and novel scaffolds. The results also increased our mechanistic understanding of Cj0843c regarding peptidoglycan GlcNAc subsite binding preferences and ligand-dependent modulation of the protonation state of the catalytic E390. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Vijay Kumar
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA
| | - Jacob Boorman
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA
| | | | - Ximin Zeng
- Department of Animal Science, University of Tennessee, Knoxville, TN, USA
| | - Jun Lin
- Department of Animal Science, University of Tennessee, Knoxville, TN, USA
| | - Focco van den Akker
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA
| |
Collapse
|
2
|
Shamma F, Papavinasasundaram K, Quintanilla SY, Bandekar A, Sassetti C, Boutte CC. Phosphorylation on PstP Regulates Cell Wall Metabolism and Antibiotic Tolerance in Mycobacterium smegmatis. J Bacteriol 2021; 203:e00563-20. [PMID: 33257524 DOI: 10.1128/JB.00563-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/18/2020] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis and its relatives, like many bacteria, have dynamic cell walls that respond to environmental stresses. Modulation of cell wall metabolism in stress is thought to be responsible for decreased permeability and increased tolerance to antibiotics. The signaling systems that control cell wall metabolism under stress, however, are poorly understood. Here, we examine the cell wall regulatory function of a key cell wall regulator, the serine/threonine phosphatase PstP, in the model organism Mycobacterium smegmatis We show that the peptidoglycan regulator CwlM is a substrate of PstP. We find that a phosphomimetic mutation, pstP T171E, slows growth, misregulates both mycolic acid and peptidoglycan metabolism in different conditions, and interferes with antibiotic tolerance. These data suggest that phosphorylation on PstP affects its activity against various substrates and is important in the transition between growth and stasis.IMPORTANCE Regulation of cell wall assembly is essential for bacterial survival and contributes to pathogenesis and antibiotic tolerance in mycobacteria, including pathogens such as Mycobacterium tuberculosis However, little is known about how the cell wall is regulated in stress. We describe a pathway of cell wall modulation in Mycobacterium smegmatis through the only essential Ser/Thr phosphatase, PstP. We showed that phosphorylation on PstP is important in regulating peptidoglycan metabolism in the transition to stasis and mycolic acid metabolism in growth. This regulation also affects antibiotic tolerance in growth and stasis. This work helps us to better understand the phosphorylation-mediated cell wall regulation circuitry in Mycobacteria.
Collapse
|
3
|
Hottmann I, Mayer VMT, Tomek MB, Friedrich V, Calvert MB, Titz A, Schäffer C, Mayer C. N-Acetylmuramic Acid (MurNAc) Auxotrophy of the Oral Pathogen Tannerella forsythia: Characterization of a MurNAc Kinase and Analysis of Its Role in Cell Wall Metabolism. Front Microbiol 2018; 9:19. [PMID: 29434575 PMCID: PMC5790795 DOI: 10.3389/fmicb.2018.00019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/05/2018] [Indexed: 01/15/2023] Open
Abstract
Tannerella forsythia is an anaerobic, Gram-negative oral pathogen that thrives in multispecies gingival biofilms associated with periodontitis. The bacterium is auxotrophic for the commonly essential bacterial cell wall sugar N-acetylmuramic acid (MurNAc) and, thus, strictly depends on an exogenous supply of MurNAc for growth and maintenance of cell morphology. A MurNAc transporter (Tf_MurT; Tanf_08375) and an ortholog of the Escherichia coli etherase MurQ (Tf_MurQ; Tanf_08385) converting MurNAc-6-phosphate to GlcNAc-6-phosphate were recently described for T. forsythia. In between the respective genes on the T. forsythia genome, a putative kinase gene is located. In this study, the putative kinase (Tf_MurK; Tanf_08380) was produced as a recombinant protein and biochemically characterized. Kinetic studies revealed Tf_MurK to be a 6-kinase with stringent substrate specificity for MurNAc exhibiting a 6 × 104-fold higher catalytic efficiency (kcat/Km ) for MurNAc than for N-acetylglucosamine (GlcNAc) with kcat values of 10.5 s-1 and 0.1 s-1 and Km values of 200 μM and 116 mM, respectively. The enzyme kinetic data suggest that Tf_MurK is subject to substrate inhibition (Ki[S] = 4.2 mM). To assess the role of Tf_MurK in the cell wall metabolism of T. forsythia, a kinase deletion mutant (ΔTf_murK::erm) was constructed. This mutant accumulated MurNAc intracellularly in the exponential phase, indicating the capability to take up MurNAc, but inability to catabolize MurNAc. In the stationary phase, the MurNAc level was reduced in the mutant, while the level of the peptidoglycan precursor UDP-MurNAc-pentapeptide was highly elevated. Further, according to scanning electron microscopy evidence, the ΔTf_murK::erm mutant was more tolerant toward low MurNAc concentration in the medium (below 0.5 μg/ml) before transition from healthy, rod-shaped to fusiform cells occurred, while the parent strain required > 1 μg/ml MurNAc for optimal growth. These data reveal that T. forsythia readily catabolizes exogenous MurNAc but simultaneously channels a proportion of the sugar into peptidoglycan biosynthesis. Deletion of Tf_murK blocks MurNAc catabolism and allows the direction of MurNAc solely to peptidoglycan biosynthesis, resulting in a growth advantage in MurNAc-depleted medium. This work increases our understanding of the T. forsythia cell wall metabolism and may pave new routes for lead finding in the treatment of periodontitis.
Collapse
Affiliation(s)
- Isabel Hottmann
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Department of Biology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Valentina M. T. Mayer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Markus B. Tomek
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Valentin Friedrich
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Matthew B. Calvert
- Chemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung, Partner Site Hannover-Braunschweig, Brunswick, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Alexander Titz
- Chemical Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung, Partner Site Hannover-Braunschweig, Brunswick, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Christina Schäffer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Christoph Mayer
- Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Department of Biology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| |
Collapse
|
4
|
Yin J, Garen CR, Cherney MM, Cherney LT, James MNG. Expression, purification and preliminary crystallographic analysis of N-acetylglucosamine-1-phosphate uridylyltransferase from Mycobacterium tuberculosis. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:805-8. [PMID: 18765909 PMCID: PMC2531282 DOI: 10.1107/s1744309108024500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2008] [Accepted: 07/31/2008] [Indexed: 05/26/2023]
Abstract
The gene product of open reading frame Rv1018c from Mycobacterium tuberculosis is annotated as encoding a probable N-acetylglucosamine 1-phosphate uridylyltransferase (MtbGlmU), an enzyme that catalyzes the biosynthesis of UDP-N-acetylglucosamine, a precursor common to lipopolysaccharide and peptidoglycan biosynthesis. Following overexpression in Escherichia coli, the enzyme was purified and crystallized using the hanging-drop vapour-diffusion method. Native diffraction data were collected from crystals belonging to space group R32 and processed to a resolution of 2.2 A.
Collapse
Affiliation(s)
- Jiang Yin
- Protein Structure and Function Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Craig R. Garen
- Protein Structure and Function Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Maia M. Cherney
- Protein Structure and Function Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Leonid T. Cherney
- Protein Structure and Function Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Michael N. G. James
- Protein Structure and Function Group, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| |
Collapse
|