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Rush JS, Zamakhaeva S, Murner NR, Deng P, Morris AJ, Kenner CW, Black I, Heiss C, Azadi P, Korotkov KV, Widmalm G, Korotkova N. Structure and mechanism of biosynthesis of Streptococcus mutans cell wall polysaccharide. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593426. [PMID: 38766245 PMCID: PMC11100793 DOI: 10.1101/2024.05.09.593426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Streptococcus mutans, the causative agent of human dental caries, expresses a cell wall attached Serotype c- specific Carbohydrate (SCC) that is critical for cell viability. SCC consists of a repeating →3)α-Rha(1→2)α-Rha(1→ polyrhamnose backbone, with glucose (Glc) side-chains and glycerol phosphate (GroP) decorations. This study reveals that SCC has one major and two minor Glc modifications. The major Glc modification, α-Glc, attached to position 2 of 3-rhamnose, is installed by SccN and SccM glycosyltransferases and is the site of the GroP addition. The minor Glc modifications are β-Glc linked to position 4 of 3-rhamnose installed by SccP and SccQ glycosyltransferases, and α-Glc attached to position 4 of 2-rhamnose installed by SccN working in tandem with an unknown enzyme. Both the major and the minor β-Glc modifications control bacterial morphology, but only the GroP and major Glc modifications are critical for biofilm formation.
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Hoopes JT, Heselpoth RD, Schwarz FP, Nelson DC. Thermal Characterization and Interaction of the Subunits from the Multimeric Bacteriophage Endolysin PlyC. BIOLOGY 2023; 12:1277. [PMID: 37886987 PMCID: PMC10604209 DOI: 10.3390/biology12101277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/12/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023]
Abstract
Bacteriophage endolysins degrade the bacterial peptidoglycan and are considered enzymatic alternatives to small-molecule antibiotics. In particular, the multimeric streptococcal endolysin PlyC has appealing antibacterial properties. However, a comprehensive thermal analysis of PlyC is lacking, which is necessary for evaluating its long-term stability and downstream therapeutic potential. Biochemical and kinetic-based methods were used in combination with differential scanning calorimetry to investigate the structural, kinetic, and thermodynamic stability of PlyC and its various subunits and domains. The PlyC holoenzyme structure is irreversibly compromised due to partial unfolding and aggregation at 46 °C. Unfolding of the catalytic subunit, PlyCA, instigates this event, resulting in the kinetic inactivation of the endolysin. In contrast to PlyCA, the PlyCB octamer (the cell wall-binding domain) is thermostable, denaturing at ~75 °C. The isolation of PlyCA or PlyCB alone altered their thermal properties. Contrary to the holoenzyme, PlyCA alone unfolds uncooperatively and is thermodynamically destabilized, whereas the PlyCB octamer reversibly dissociates into monomers and forms an intermediate state at 74 °C in phosphate-buffered saline with each subunit subsequently denaturing at 92 °C. Adding folded PlyCA to an intermediate state PlyCB, followed by cooling, allowed for in vitro reconstitution of the active holoenzyme.
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Affiliation(s)
- J. Todd Hoopes
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (J.T.H.); (R.D.H.)
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Ryan D. Heselpoth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (J.T.H.); (R.D.H.)
| | - Frederick P. Schwarz
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (J.T.H.); (R.D.H.)
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Daniel C. Nelson
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (J.T.H.); (R.D.H.)
- Department of Veterinary Medicine, University of Maryland, College Park, MD 20740, USA
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Alreja AB, Linden SB, Lee HR, Chao KL, Herzberg O, Nelson DC. Understanding the Molecular Basis for Homodimer Formation of the Pneumococcal Endolysin Cpl-1. ACS Infect Dis 2023; 9:1092-1104. [PMID: 37126660 PMCID: PMC10577085 DOI: 10.1021/acsinfecdis.2c00627] [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] [Indexed: 05/03/2023]
Abstract
The rise of multi-drug-resistant bacteria that cannot be treated with traditional antibiotics has prompted the search for alternatives to combat bacterial infections. Endolysins, which are bacteriophage-derived peptidoglycan hydrolases, are attractive tools in this fight. Several studies have already demonstrated the efficacy of endolysins in targeting bacterial infections. Endolysins encoded by bacteriophages that infect Gram-positive bacteria typically possess an N-terminal catalytic domain and a C-terminal cell-wall binding domain (CWBD). In this study, we have uncovered the molecular mechanisms that underlie formation of a homodimer of Cpl-1, an endolysin that targets Streptococcus pneumoniae. Here, we use site-directed mutagenesis, analytical size exclusion chromatography, and analytical ultracentrifugation to disprove a previous suggestion that three residues at the N-terminus of the CWBD are involved in the formation of a Cpl-1 dimer in the presence of choline in solution. We conclusively show that the C-terminal tail region of Cpl-1 is involved in formation of the dimer. Alanine scanning mutagenesis generated various tail mutant constructs that allowed identification of key residues that mediate Cpl-1 dimer formation. Finally, our results allowed identification of a consensus sequence (FxxEPDGLIT) required for choline-dependent dimer formation─a sequence that occurs frequently in pneumococcal autolysins and endolysins. These findings shed light on the mechanisms of Cpl-1 and related enzymes and can be used to inform future engineering efforts for their therapeutic development against S. pneumoniae.
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Affiliation(s)
- Adit B Alreja
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Biological Sciences Graduate Program - Molecular and Cellular Biology Concentration, University of Maryland, College Park, Maryland 20742, USA
| | - Sara B Linden
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
| | - Harrison R Lee
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
| | - Kinlin L Chao
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Department of Biochemistry and Chemistry, University of Maryland, College Park, Maryland 20742, USA
| | - Daniel C Nelson
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland 20742, USA
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Harhala MA, Gembara K, Nelson DC, Miernikiewicz P, Dąbrowska K. Immunogenicity of Endolysin PlyC. Antibiotics (Basel) 2022; 11:966. [PMID: 35884219 PMCID: PMC9312349 DOI: 10.3390/antibiotics11070966] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/14/2022] [Accepted: 07/16/2022] [Indexed: 12/10/2022] Open
Abstract
Endolysins are bacteriolytic enzymes derived from bacteriophages. They represent an alternative to antibiotics, since they are not susceptible to conventional antimicrobial resistance mechanisms. Since non-human proteins are efficient inducers of specific immune responses, including the IgG response or the development of an allergic response mediated by IgE, we evaluated the general immunogenicity of the highly active antibacterial enzyme, PlyC, in a human population and in a mouse model. The study includes the identification of molecular epitopes of PlyC. The overall assessment of potential hypersensitivity to this protein and PlyC-specific IgE testing was also conducted in mice. PlyC induced efficient IgG production in mice, and the molecular analysis revealed that PlyC-specific IgG interacted with four immunogenic regions identified within the PlyCA subunit. In humans, approximately 10% of the population demonstrated IgG reactivity to the PlyCB subunit only, which is attributed to cross-reactions since this was a naïve serum. Of note, in spite of being immunogenic, PlyC induced a normal immune response, without hypersensitivity, since both the animals challenged with PlyC and in the human population PlyC-specific IgE was not detected.
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Affiliation(s)
- Marek Adam Harhala
- Laboratory of Phage Molecular Biology, Department of Phage Therapy, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.A.H.); (K.G.); (P.M.)
- Research & Development Center, Regional Specialist Hospital, 53-114 Wroclaw, Poland
| | - Katarzyna Gembara
- Laboratory of Phage Molecular Biology, Department of Phage Therapy, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.A.H.); (K.G.); (P.M.)
- Research & Development Center, Regional Specialist Hospital, 53-114 Wroclaw, Poland
| | - Daniel C. Nelson
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20853, USA;
| | - Paulina Miernikiewicz
- Laboratory of Phage Molecular Biology, Department of Phage Therapy, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.A.H.); (K.G.); (P.M.)
| | - Krystyna Dąbrowska
- Laboratory of Phage Molecular Biology, Department of Phage Therapy, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland; (M.A.H.); (K.G.); (P.M.)
- Research & Development Center, Regional Specialist Hospital, 53-114 Wroclaw, Poland
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Radkov A, Sapiro AL, Flores S, Henderson C, Saunders H, Kim R, Massa S, Thompson S, Mateusiak C, Biboy J, Zhao Z, Starita LM, Hatleberg WL, Vollmer W, Russell AB, Simorre JP, Anthony-Cahill S, Brzovic P, Hayes B, Chou S. Antibacterial potency of Type VI amidase effector toxins is dependent on substrate topology and cellular context. eLife 2022; 11:79796. [PMID: 35762582 PMCID: PMC9270033 DOI: 10.7554/elife.79796] [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: 05/22/2022] [Accepted: 06/23/2022] [Indexed: 11/15/2022] Open
Abstract
Members of the bacterial T6SS amidase effector (Tae) superfamily of toxins are delivered between competing bacteria to degrade cell wall peptidoglycan. Although Taes share a common substrate, they exhibit distinct antimicrobial potency across different competitor species. To investigate the molecular basis governing these differences, we quantitatively defined the functional determinants of Tae1 from Pseudomonas aeruginosa PAO1 using a combination of nuclear magnetic resonance and a high-throughput in vivo genetic approach called deep mutational scanning (DMS). As expected, combined analyses confirmed the role of critical residues near the Tae1 catalytic center. Unexpectedly, DMS revealed substantial contributions to enzymatic activity from a much larger, ring-like functional hot spot extending around the entire circumference of the enzyme. Comparative DMS across distinct growth conditions highlighted how functional contribution of different surfaces is highly context-dependent, varying alongside composition of targeted cell walls. These observations suggest that Tae1 engages with the intact cell wall network through a more distributed three-dimensional interaction interface than previously appreciated, providing an explanation for observed differences in antimicrobial potency across divergent Gram-negative competitors. Further binding studies of several Tae1 variants with their cognate immunity protein demonstrate that requirements to maintain protection from Tae activity may be a significant constraint on the mutational landscape of tae1 toxicity in the wild. In total, our work reveals that Tae diversification has likely been shaped by multiple independent pressures to maintain interactions with binding partners that vary across bacterial species and conditions.
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Affiliation(s)
- Atanas Radkov
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Anne L Sapiro
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | | | | | - Hayden Saunders
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Rachel Kim
- Pacific Northwest University of Health Sciences, Yakima, United States
| | - Steven Massa
- Department of Biology, Stanford University, Stanford, United States
| | - Samuel Thompson
- Department of Bioengineering, Stanford University, Stanford, United States
| | - Chase Mateusiak
- Computer Science Department, Washington University in St. Louis, St. Louis, United States
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Ziyi Zhao
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Lea M Starita
- Department of Genome Sciences, University of Washington, Seattle, United States
| | | | - Waldemar Vollmer
- Center for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Alistair B Russell
- Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France
| | | | - Peter Brzovic
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Beth Hayes
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Seemay Chou
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
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Rahman MU, Wang W, Sun Q, Shah JA, Li C, Sun Y, Li Y, Zhang B, Chen W, Wang S. Endolysin, a Promising Solution against Antimicrobial Resistance. Antibiotics (Basel) 2021; 10:1277. [PMID: 34827215 PMCID: PMC8614784 DOI: 10.3390/antibiotics10111277] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 12/24/2022] Open
Abstract
Antimicrobial resistance (AMR) is a global crisis for human public health which threatens the effective prevention and control of ever-increasing infectious diseases. The advent of pandrug-resistant bacteria makes most, if not all, available antibiotics invalid. Meanwhile, the pipeline of novel antibiotics development stagnates, which prompts scientists and pharmacists to develop unconventional antimicrobials. Bacteriophage-derived endolysins are cell wall hydrolases which could hydrolyze the peptidoglycan layer from within and outside of bacterial pathogens. With high specificity, rapid action, high efficiency, and low risk of resistance development, endolysins are believed to be among the best alternative therapeutic agents to treat multidrug resistant (MDR) bacteria. As of now, endolysins have been applied to diverse aspects. In this review, we comprehensively introduce the structures and activities of endolysins and summarize the latest application progress of recombinant endolysins in the fields of medical treatment, pathogen diagnosis, food safety, and agriculture.
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Affiliation(s)
- Mujeeb ur Rahman
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
| | - Weixiao Wang
- Clinical Research Center, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China;
| | - Qingqing Sun
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
| | - Junaid Ali Shah
- College of Life Sciences, Jilin University, Changchun 130012, China;
| | - Chao Li
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
| | - Yanmei Sun
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
| | - Yuanrui Li
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
| | - Bailing Zhang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, China;
| | - Wei Chen
- Clinical Research Center, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing 210003, China;
| | - Shiwei Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China; (M.u.R.); (Q.S.); (C.L.); (Y.S.); (Y.L.)
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7
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King H, Ajay Castro S, Pohane AA, Scholte CM, Fischetti VA, Korotkova N, Nelson DC, Dorfmueller HC. Molecular basis for recognition of the Group A Carbohydrate backbone by the PlyC streptococcal bacteriophage endolysin. Biochem J 2021; 478:2385-2397. [PMID: 34096588 PMCID: PMC8555655 DOI: 10.1042/bcj20210158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/25/2021] [Accepted: 06/07/2021] [Indexed: 11/17/2022]
Abstract
Endolysins are peptidoglycan (PG) hydrolases that function as part of the bacteriophage (phage) lytic system to release progeny phage at the end of a replication cycle. Notably, endolysins alone can produce lysis without phage infection, which offers an attractive alternative to traditional antibiotics. Endolysins from phage that infect Gram-positive bacterial hosts contain at least one enzymatically active domain (EAD) responsible for hydrolysis of PG bonds and a cell wall binding domain (CBD) that binds a cell wall epitope, such as a surface carbohydrate, providing some degree of specificity for the endolysin. Whilst the EADs typically cluster into conserved mechanistic classes with well-defined active sites, relatively little is known about the nature of the CBDs and only a few binding epitopes for CBDs have been elucidated. The major cell wall components of many streptococci are the polysaccharides that contain the polyrhamnose (pRha) backbone modified with species-specific and serotype-specific glycosyl side chains. In this report, using molecular genetics, microscopy, flow cytometry and lytic activity assays, we demonstrate the interaction of PlyCB, the CBD subunit of the streptococcal PlyC endolysin, with the pRha backbone of the cell wall polysaccharides, Group A Carbohydrate (GAC) and serotype c-specific carbohydrate (SCC) expressed by the Group A Streptococcus and Streptococcus mutans, respectively.
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Affiliation(s)
- Harley King
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Sowmya Ajay Castro
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Amol Arunrao Pohane
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, U.S.A
| | - Cynthia M Scholte
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Vincent A Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York, NY, U.S.A
| | - Natalia Korotkova
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, U.S.A
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, U.S.A
| | - Daniel C Nelson
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, U.S.A
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, U.K
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