1
|
Hsu TW, Fang JM. Advances and prospects of analytic methods for bacterial transglycosylation and inhibitor discovery. Analyst 2024; 149:2204-2222. [PMID: 38517346 DOI: 10.1039/d3an01968c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
The cell wall is essential for bacteria to maintain structural rigidity and withstand external osmotic pressure. In bacteria, the cell wall is composed of peptidoglycan. Lipid II is the basic unit for constructing highly cross-linked peptidoglycan scaffolds. Transglycosylase (TGase) is the initiating enzyme in peptidoglycan synthesis that catalyzes the ligation of lipid II moieties into repeating GlcNAc-MurNAc polysaccharides, followed by transpeptidation to generate cross-linked structures. In addition to the transglycosylases in the class-A penicillin-binding proteins (aPBPs), SEDS (shape, elongation, division and sporulation) proteins are also present in most bacteria and play vital roles in cell wall renewal, elongation, and division. In this review, we focus on the latest analytical methods including the use of radioactive labeling, gel electrophoresis, mass spectrometry, fluorescence labeling, probing undecaprenyl pyrophosphate, fluorescence anisotropy, ligand-binding-induced tryptophan fluorescence quenching, and surface plasmon resonance to evaluate TGase activity in cell wall formation. This review also covers the discovery of TGase inhibitors as potential antibacterial agents. We hope that this review will give readers a better understanding of the chemistry and basic research for the development of novel antibiotics.
Collapse
Affiliation(s)
- Tse-Wei Hsu
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
| | - Jim-Min Fang
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
| |
Collapse
|
2
|
Liu Y, Zhang Y, Kang C, Tian D, Lu H, Xu B, Xia Y, Kashiwagi A, Westermann M, Hoischen C, Xu J, Yomo T. Comparative genomics hints at dispensability of multiple essential genes in two Escherichia coli L-form strains. Biosci Rep 2023; 43:BSR20231227. [PMID: 37819245 PMCID: PMC10600066 DOI: 10.1042/bsr20231227] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/09/2023] [Accepted: 10/11/2023] [Indexed: 10/13/2023] Open
Abstract
Despite the critical role of bacterial cell walls in maintaining cell shapes, certain environmental stressors can induce the transition of many bacterial species into a wall-deficient state called L-form. Long-term induced Escherichia coli L-forms lose their rod shape and usually hold significant mutations that affect cell division and growth. Besides this, the genetic background of L-form bacteria is still poorly understood. In the present study, the genomes of two stable L-form strains of E. coli (NC-7 and LWF+) were sequenced and their gene mutation status was determined and compared with their parental strains. Comparative genomic analysis between two L-forms reveals both unique adaptions and common mutated genes, many of which belong to essential gene categories not involved in cell wall biosynthesis, indicating that L-form genetic adaptation impacts crucial metabolic pathways. Missense variants from L-forms and Lenski's long-term evolution experiment (LTEE) were analyzed in parallel using an optimized DeepSequence pipeline to investigate predicted mutation effects (α) on protein functions. We report that the two L-form strains analyzed display a frequency of 6-10% (0% for LTEE) in mutated essential genes where the missense variants have substantial impact on protein functions (α<0.5). This indicates the emergence of different survival strategies in L-forms through changes in essential genes during adaptions to cell wall deficiency. Collectively, our results shed light on the detailed genetic background of two E. coli L-forms and pave the way for further investigations of the gene functions in L-form bacterial models.
Collapse
Affiliation(s)
- Yunfei Liu
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Yueyue Zhang
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Chen Kang
- School of Software Engineering, East China Normal University, Shanghai 200062, PR China
| | - Di Tian
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Hui Lu
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Boying Xu
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
- Tongji University Cancer Center, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai 200072, China
| | - Yang Xia
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Akiko Kashiwagi
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Martin Westermann
- Center for Electron Microscopy, Medical Faculty, Friedrich–Schiller–University Jena, Ziegelmühlenweg 1, D-07743 Jena, Germany
| | - Christian Hoischen
- CF Imaging, Leibniz Institute On Aging, Fritz–Lipmann–Institute (FLI), Beutenbergstraße 11, 07745 Jena, Germany
| | - Jian Xu
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| | - Tetsuya Yomo
- Laboratory of Biology and Information Science, School of Life Sciences, East China Normal University, Shanghai 200062, PR China
| |
Collapse
|
3
|
Kado T, Akbary Z, Motooka D, Sparks IL, Melzer ES, Nakamura S, Rojas ER, Morita YS, Siegrist MS. A cell wall synthase accelerates plasma membrane partitioning in mycobacteria. eLife 2023; 12:e81924. [PMID: 37665120 PMCID: PMC10547480 DOI: 10.7554/elife.81924] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 09/02/2023] [Indexed: 09/05/2023] Open
Abstract
Lateral partitioning of proteins and lipids shapes membrane function. In model membranes, partitioning can be influenced both by bilayer-intrinsic factors like molecular composition and by bilayer-extrinsic factors such as interactions with other membranes and solid supports. While cellular membranes can departition in response to bilayer-intrinsic or -extrinsic disruptions, the mechanisms by which they partition de novo are largely unknown. The plasma membrane of Mycobacterium smegmatis spatially and biochemically departitions in response to the fluidizing agent benzyl alcohol, then repartitions upon fluidizer washout. By screening for mutants that are sensitive to benzyl alcohol, we show that the bifunctional cell wall synthase PonA2 promotes membrane partitioning and cell growth during recovery from benzyl alcohol exposure. PonA2's role in membrane repartitioning and regrowth depends solely on its conserved transglycosylase domain. Active cell wall polymerization promotes de novo membrane partitioning and the completed cell wall polymer helps to maintain membrane partitioning. Our work highlights the complexity of membrane-cell wall interactions and establishes a facile model system for departitioning and repartitioning cellular membranes.
Collapse
Affiliation(s)
- Takehiro Kado
- Department of Microbiology, University of Massachusetts AmherstAmherstUnited States
| | - Zarina Akbary
- Department of Biology, New York UniversityNew YorkUnited States
| | - Daisuke Motooka
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts AmherstAmherstUnited States
| | - Emily S Melzer
- Department of Microbiology, University of Massachusetts AmherstAmherstUnited States
| | - Shota Nakamura
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka UniversityOsakaJapan
| | - Enrique R Rojas
- Department of Biology, New York UniversityNew YorkUnited States
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts AmherstAmherstUnited States
- Molecular and Cellular Graduate Program, University of Massachusetts AmherstAmherstUnited States
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts AmherstAmherstUnited States
- Molecular and Cellular Graduate Program, University of Massachusetts AmherstAmherstUnited States
| |
Collapse
|
4
|
Martinez-Bond EA, Soriano BM, Williams AH. The mechanistic landscape of Lytic transglycosylase as targets for antibacterial therapy. Curr Opin Struct Biol 2022; 77:102480. [PMID: 36323133 DOI: 10.1016/j.sbi.2022.102480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/24/2022] [Accepted: 09/09/2022] [Indexed: 12/14/2022]
Abstract
Lytic transglycosylases (Ltgs) are glycan strand cleaving enzymes whose role is poorly understood in the genesis of the bacterial envelope. They play multiple roles in all stages of a bacterial life cycle, by creating holes in the peptidoglycan that is necessary for cell division and separation. Here, we review recent advances in understanding the suitability of Ltgs as antibacterial drug targets. We specifically highlight a known inhibitor bulgecin A that is able to inhibit the function of structurally diverse Ltgs, as well as synergize with beta-lactams to improve its efficacy in antibiotic insensitive strains. Discovery of new antibiotics or new targets has been challenging. These studies could provide a viable path toward designing broad-spectrum inhibitors that targets Ltgs.
Collapse
Affiliation(s)
- Elizabeth A Martinez-Bond
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA. https://twitter.com/bondlizbond
| | - Berliza M Soriano
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA. https://twitter.com/AWilliamslab
| | - Allison H Williams
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
| |
Collapse
|
5
|
Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
Collapse
Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
| |
Collapse
|
6
|
Hemez C, Clarelli F, Palmer AC, Bleis C, Abel S, Chindelevitch L, Cohen T, Abel zur Wiesch P. Mechanisms of antibiotic action shape the fitness landscapes of resistance mutations. Comput Struct Biotechnol J 2022; 20:4688-4703. [PMID: 36147681 PMCID: PMC9463365 DOI: 10.1016/j.csbj.2022.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 11/15/2022] Open
Abstract
Antibiotic-resistant pathogens are a major public health threat. A deeper understanding of how an antibiotic's mechanism of action influences the emergence of resistance would aid in the design of new drugs and help to preserve the effectiveness of existing ones. To this end, we developed a model that links bacterial population dynamics with antibiotic-target binding kinetics. Our approach allows us to derive mechanistic insights on drug activity from population-scale experimental data and to quantify the interplay between drug mechanism and resistance selection. We find that both bacteriostatic and bactericidal agents can be equally effective at suppressing the selection of resistant mutants, but that key determinants of resistance selection are the relationships between the number of drug-inactivated targets within a cell and the rates of cellular growth and death. We also show that heterogeneous drug-target binding within a population enables resistant bacteria to evolve fitness-improving secondary mutations even when drug doses remain above the resistant strain's minimum inhibitory concentration. Our work suggests that antibiotic doses beyond this "secondary mutation selection window" could safeguard against the emergence of high-fitness resistant strains during treatment.
Collapse
Affiliation(s)
- Colin Hemez
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Graduate Program in Biophysics, Harvard University, Boston, MA 02115, USA
- Corresponding authors at: Broad Institute, 75 Ames St, Room 3035, Cambridge, MA 02412, USA (C. Hemez). Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway (P. Abel zur Wiesch).
| | - Fabrizio Clarelli
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Adam C. Palmer
- Department of Pharmacology, Computational Medicine Program, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Christina Bleis
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Sören Abel
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Division of Infection Control, Norwegian Institute of Public Health, Oslo 0318, Norway
| | - Leonid Chindelevitch
- Department of Infectious Disease Epidemiology, Imperial College, London SW7 2AZ, UK
| | - Theodore Cohen
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06520, USA
| | - Pia Abel zur Wiesch
- Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
- Division of Infection Control, Norwegian Institute of Public Health, Oslo 0318, Norway
- Corresponding authors at: Broad Institute, 75 Ames St, Room 3035, Cambridge, MA 02412, USA (C. Hemez). Department of Pharmacy, UiT – The Arctic University of Norway, 9019 Tromsø, Norway (P. Abel zur Wiesch).
| |
Collapse
|
7
|
OUP accepted manuscript. J Antimicrob Chemother 2022; 77:1847-1850. [DOI: 10.1093/jac/dkac139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/05/2022] [Indexed: 11/15/2022] Open
|
8
|
Wang Y, Liang Z, Zheng Y, Leung ASL, Yan SC, So PK, Leung YC, Wong WL, Wong KY. Rational structural modification of the isatin scaffold to develop new and potent antimicrobial agents targeting bacterial peptidoglycan glycosyltransferase. RSC Adv 2021; 11:18122-18130. [PMID: 35480164 PMCID: PMC9033243 DOI: 10.1039/d1ra02119b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/10/2021] [Indexed: 12/11/2022] Open
Abstract
A series of isatin derivatives bearing three different substituent groups at the N-1, C-3 and C-5 positions of the isatin scaffold were systematically designed and synthesized to study the structure-activity relationship of their inhibition of bacterial peptidoglycan glycosyltransferase (PGT) activity and antimicrobial susceptibility against S. aureus, E. coli and methicillin-resistant Staphylococcus aureus (MRSA (BAA41)) strains. The substituents at these sites are pointing towards three different directions from the isatin scaffold to interact with the amino acid residues in the binding pocket of PGT. Comparative studies of their structure-activity relationship allow us to gain better understanding of the direction of the substituents that contribute critical interactions leading to inhibition activity against the bacterial enzyme. Our results indicate that the modification of these sites is able to maximize the antimicrobial potency and inhibitory action against the bacterial enzyme. Two compounds show good antimicrobial potency (MIC = 3 μg mL-1 against S. aureus and MRSA; 12-24 μg mL-1 against E. coli). Results of the inhibition study against the bacterial enzyme (E. coli PBP 1b) reveal that some compounds are able to achieve excellent in vitro inhibitions of bacterial enzymatic activity (up to 100%). The best half maximal inhibitory concentration (IC50) observed among the new compounds is 8.9 μM.
Collapse
Affiliation(s)
- Yong Wang
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Zhiguang Liang
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Yuanyuan Zheng
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Alan Siu-Lun Leung
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Siu-Cheong Yan
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Pui-Kin So
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Yun-Chung Leung
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Wing-Leung Wong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| | - Kwok-Yin Wong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Hunghom Kowloon Hong Kong P. R. China
| |
Collapse
|
9
|
Discovery of Pyrrolidine-2,3-diones as Novel Inhibitors of P. aeruginosa PBP3. Antibiotics (Basel) 2021; 10:antibiotics10050529. [PMID: 34064358 PMCID: PMC8147781 DOI: 10.3390/antibiotics10050529] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 12/01/2022] Open
Abstract
The alarming threat of the spread of multidrug resistant bacteria currently leaves clinicians with very limited options to combat infections, especially those from Gram-negative bacteria. Hence, innovative strategies to deliver the next generation of antibacterials are urgently needed. Penicillin binding proteins (PBPs) are proven targets inhibited by β-lactam antibiotics. To discover novel, non-β-lactam inhibitors against PBP3 of Pseudomonas aeruginosa, we optimised a fluorescence assay based on a well-known thioester artificial substrate and performed a target screening using a focused protease-targeted library of 2455 compounds, which led to the identification of pyrrolidine-2,3-dione as a potential scaffold to inhibit the PBP3 target. Further chemical optimisation using a one-pot three-component reaction protocol delivered compounds with excellent target inhibition, initial antibacterial activities against P. aeruginosa and no apparent cytotoxicity. Our investigation revealed the key structural features; for instance, 3-hydroxyl group (R2) and a heteroaryl group (R1) appended to the N-pyrroldine-2,3-dione via methylene linker required for target inhibition. Overall, the discovery of the pyrrolidine-2,3-dione class of inhibitors of PBP3 brings opportunities to target multidrug-resistant bacterial strains and calls for further optimisation to improve antibacterial activity against P. aeruginosa.
Collapse
|
10
|
Yin J, Zhang T, Cai J, Lou J, Cheng D, Zhou W, Xu C, Liu Y, Gao H, Yu Z. PBP1a glycosyltransferase and transpeptidase activities are both required for maintaining cell morphology and envelope integrity in Shewanella oneidensis. FEMS Microbiol Lett 2021; 367:5731804. [PMID: 32037461 DOI: 10.1093/femsle/fnaa026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/07/2020] [Indexed: 12/29/2022] Open
Abstract
In rod-shaped Gram-negative bacteria, penicillin binding protein 1a (PBP1a) and 1b (PBP1b) form peptidoglycan-synthesizing complexes with the outer membrane lipoprotein LpoA and LpoB, respectively. Escherichia coli mutants lacking PBP1b/LpoB are sicker than those lacking PBP1a/LpoA. However, we previously found that mutants lacking PBP1a/LpoA but not PBP1b/LpoB are deleterious in Shewanella oneidensis. Here, we show that S. oneidensis PBP1a (SoPBP1a) contains conserved signature motifs with its E. coli counterpart, EcPBP1a. Although EcPBP1a play a less prominent role in E. coli, it is capable of substituting for the SoPBP1a in a manner dependent on SoLpoA. In S. oneidensis, expression of PBP1b is lower than PBP1a, and therefore the additional expression of SoPBP1b at low levels can functionally compensate for the absence of SoPBP1a. Importantly, S. oneidensis PBP1a variants lacking either glycosyltransferase (GTase) or transpeptidase (TPase) activity fail to maintain normal morphology and cell envelope integrity. Similarly, SoPBP1b variants also fail to compensate for the loss of SoPBP1a. Furthermore, overproduction of variants of SoPBP1a, but not SoPBP1b, has detrimental effects on cell morphology in S. oneidensis wild type cells. Overall, our results indicate that the combined enzymatic activities of SoPBP1a are essential for cell wall homeostasis.
Collapse
Affiliation(s)
- Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Ting Zhang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Jingxiao Cai
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Jie Lou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Dan Cheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Weifeng Zhou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Chaoyi Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Yanqiu Liu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| | - Haichun Gao
- College of Life sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang Province, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, Zhejiang Province, China
| |
Collapse
|
11
|
Boes A, Kerff F, Herman R, Touze T, Breukink E, Terrak M. The bacterial cell division protein fragment EFtsN binds to and activates the major peptidoglycan synthase PBP1b. J Biol Chem 2020; 295:18256-18265. [PMID: 33109614 PMCID: PMC7939390 DOI: 10.1074/jbc.ra120.015951] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
Peptidoglycan (PG) is an essential constituent of the bacterial cell wall. During cell division, the machinery responsible for PG synthesis localizes mid-cell, at the septum, under the control of a multiprotein complex called the divisome. In Escherichia coli, septal PG synthesis and cell constriction rely on the accumulation of FtsN at the division site. Interestingly, a short sequence of FtsN (Leu75-Gln93, known as EFtsN) was shown to be essential and sufficient for its functioning in vivo, but what exactly this sequence is doing remained unknown. Here, we show that EFtsN binds specifically to the major PG synthase PBP1b and is sufficient to stimulate its biosynthetic glycosyltransferase (GTase) activity. We also report the crystal structure of PBP1b in complex with EFtsN, which demonstrates that EFtsN binds at the junction between the GTase and UB2H domains of PBP1b. Interestingly, mutations to two residues (R141A/R397A) within the EFtsN-binding pocket reduced the activation of PBP1b by FtsN but not by the lipoprotein LpoB. This mutant was unable to rescue the ΔponB-ponAts strain, which lacks PBP1b and has a thermosensitive PBP1a, at nonpermissive temperature and induced a mild cell-chaining phenotype and cell lysis. Altogether, the results show that EFtsN interacts with PBP1b and that this interaction plays a role in the activation of its GTase activity by FtsN, which may contribute to the overall septal PG synthesis and regulation during cell division.
Collapse
Affiliation(s)
- Adrien Boes
- InBioS-Centre d'Ingénierie des Protéines, Liège University, Liège, Belgium
| | - Frederic Kerff
- InBioS-Centre d'Ingénierie des Protéines, Liège University, Liège, Belgium
| | - Raphael Herman
- InBioS-Centre d'Ingénierie des Protéines, Liège University, Liège, Belgium
| | - Thierry Touze
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Mohammed Terrak
- InBioS-Centre d'Ingénierie des Protéines, Liège University, Liège, Belgium.
| |
Collapse
|
12
|
New insights in the coordinated amidase and glucosaminidase activity of the major autolysin (Atl) in Staphylococcus aureus. Commun Biol 2020; 3:695. [PMID: 33219282 PMCID: PMC7679415 DOI: 10.1038/s42003-020-01405-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022] Open
Abstract
After bacterial cell division, the daughter cells are still covalently interlinked by the peptidoglycan network which is resolved by specific hydrolases (autolysins) to release the daughter cells. In staphylococci, the major autolysin (Atl) with its two domain enzymes, N-acetylmuramyl-L-alanine amidase (AmiA) and β-N-acetylglucosaminidase (GlcA), resolves the peptidoglycan to release the daughter cells. Internal deletions in each of the enzyme domains revealed defined morphological alterations such as cell cluster formation in ΔamiA, ΔglcA and Δatl, and asymmetric cell division in the ΔglcA. A most important finding was that GlcA activity requires the prior removal of the stem peptide by AmiA for its activity thus the naked glycan strand is its substrate. Furthermore, GlcA is not an endo-β-N-acetylglucosaminidase but an exo-enzyme that cuts the glycan backbone to disaccharides independent of its O-acetylation modification. Our results shed new light into the sequential peptidoglycan hydrolysis by AmiA and GlcA during cell division in staphylococci. Nega et al. shed light on the interplay of the two domain enzymes of the major autolysin, AmiA and GlcA, in S. aureus for peptidoglycan hydrolysis during bacterial cell division. They show that GlcA requires the prior removal of the stem peptide by AmiA for its activity and that GlcA is not an endo-enzyme as previously thought, but an exo-enzyme that chops down the glycan backbone to disaccharides independent of its O-acetylation modification.
Collapse
|
13
|
Goossens K, Neves RP, Fernandes PA, De Winter H. A Computational and Modeling Study of the Reaction Mechanism of Staphylococcus aureus Monoglycosyltransferase Reveals New Insights on the GT51 Family of Enzymes. J Chem Inf Model 2020; 60:5513-5528. [PMID: 32786224 DOI: 10.1021/acs.jcim.0c00377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Bacterial glycosyltransferases of the GT51 family are key enzymes in bacterial cell wall synthesis. Inhibiting cell wall synthesis is a very effective approach for development of antibiotics, as this can lead to either bacteriostatic or bactericidal effects. Even though the existence of this family has been known for over 50 years, only one potent inhibitor exists, which is an analog of the lipid IV product and derived from a natural product. Drug development focused on bacterial transglycosylase has been hampered due to little being know about its structure and reaction mechanism. In this study, Staphylococcus aureus monoglycosyltransferase was investigated at an atomistic level using computational methods. Classical molecular dynamics simulations were used to reveal information about the large-scale dynamics of the enzyme-substrate complex and the importance of magnesium in structure and function of the protein, while mixed mode quantum mechanics/molecular mechanics calculations unveiled a novel hypothesis for the reaction mechanism. From these results, we present a new model for the binding mode of lipid II and the reaction mechanism of the GT51 glycosyltransferases. A metal-bound hydroxide catalyzed reaction mechanism yields an estimated free energy barrier of 16.1 ± 1.0 kcal/mol, which is in line with experimental values. The importance of divalent cations is also further discussed. These findings could significantly aid targeted drug design, particularly the efficient development of transition state analogues as potential inhibitors for the GT51 glycosyltransferases.
Collapse
Affiliation(s)
- Kenneth Goossens
- Department of Pharmaceutical Sciences, Laboratory of Medicinal Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Rui Pp Neves
- LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro A Fernandes
- LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Hans De Winter
- Department of Pharmaceutical Sciences, Laboratory of Medicinal Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| |
Collapse
|
14
|
Boes A, Brunel JM, Derouaux A, Kerff F, Bouhss A, Touze T, Breukink E, Terrak M. Squalamine and Aminosterol Mimics Inhibit the Peptidoglycan Glycosyltransferase Activity of PBP1b. Antibiotics (Basel) 2020; 9:antibiotics9070373. [PMID: 32630634 PMCID: PMC7400108 DOI: 10.3390/antibiotics9070373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 11/20/2022] Open
Abstract
Peptidoglycan (PG) is an essential polymer of the bacterial cell wall and a major antibacterial target. Its synthesis requires glycosyltransferase (GTase) and transpeptidase enzymes that, respectively, catalyze glycan chain elongation and their cross-linking to form the protective sacculus of the bacterial cell. The GTase domain of bifunctional penicillin-binding proteins (PBPs) of class A, such as Escherichia coli PBP1b, belong to the GTase 51 family. These enzymes play an essential role in PG synthesis, and their specific inhibition by moenomycin was shown to lead to bacterial cell death. In this work, we report that the aminosterol squalamine and mimic compounds present an unexpected mode of action consisting in the inhibition of the GTase activity of the model enzyme PBP1b. In addition, selected compounds were able to specifically displace the lipid II from the active site in a fluorescence anisotropy assay, suggesting that they act as competitive inhibitors.
Collapse
Affiliation(s)
- Adrien Boes
- InBioS-Centre d’Ingénierie des Protéines, Liège University, 4000 Liège, Belgium; (A.B.); (A.D.); (F.K.)
| | - Jean Michel Brunel
- UMR_MD1, U-1261, Aix Marseille Univ, INSERM, SSA, MCT, 13385 Marseille, France;
| | - Adeline Derouaux
- InBioS-Centre d’Ingénierie des Protéines, Liège University, 4000 Liège, Belgium; (A.B.); (A.D.); (F.K.)
| | - Frédéric Kerff
- InBioS-Centre d’Ingénierie des Protéines, Liège University, 4000 Liège, Belgium; (A.B.); (A.D.); (F.K.)
| | - Ahmed Bouhss
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (A.B.); (T.T.)
- Laboratoire Structure-Activite des Biomolecules Normales et Pathologiques (SABNP), Univ Evry, INSERM U1204, Universite Paris-Saclay, 91025 Evry, France
| | - Thierry Touze
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198 Gif-sur-Yvette, France; (A.B.); (T.T.)
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands;
| | - Mohammed Terrak
- InBioS-Centre d’Ingénierie des Protéines, Liège University, 4000 Liège, Belgium; (A.B.); (A.D.); (F.K.)
- Correspondence: ; Tel.: +33-4366-3332
| |
Collapse
|
15
|
Fluorescence anisotropy assays for high throughput screening of compounds binding to lipid II, PBP1b, FtsW and MurJ. Sci Rep 2020; 10:6280. [PMID: 32286439 PMCID: PMC7156629 DOI: 10.1038/s41598-020-63380-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/30/2020] [Indexed: 12/03/2022] Open
Abstract
Lipid II precursor and its processing by a flippase and peptidoglycan polymerases are considered key hot spot targets for antibiotics. We have developed a fluorescent anisotropy (FA) assay using a unique and versatile probe (fluorescent lipid II) and monitored direct binding between lipid II and interacting proteins (PBP1b, FtsW and MurJ), as well as between lipid II and interacting antibiotics (vancomycin, nisin, ramoplanin and a small molecule). Competition experiments performed using unlabelled lipid II, four lipid II-binding antibiotics and moenomycin demonstrate that the assay can detect compounds interacting with lipid II or the proteins. These results provide a proof-of-concept for the use of this assay in a high-throughput screening of compounds against all these targets. In addition, the assay constitutes a powerful tool in the study of the mode of action of compounds that interfere with these processes. Interestingly, FA assay with lipid II probe has the advantage over moenomycin based probe to potentially identify compounds that interfere with both donor and acceptor sites of the aPBPs GTase as well as compounds that bind to lipid II. In addition, this assay would allow the screening of compounds against SEDS proteins and MurJ which do not interact with moenomycin.
Collapse
|
16
|
Baindara P, Ghosh AK, Mandal SM. Coevolution of Resistance Against Antimicrobial Peptides. Microb Drug Resist 2020; 26:880-899. [PMID: 32119634 DOI: 10.1089/mdr.2019.0291] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) are produced by all forms of life, ranging from eukaryotes to prokaryotes, and they are a crucial component of innate immunity, involved in clearing infection by inhibiting pathogen colonization. In the recent past, AMPs received high attention due to the increase of extensive antibiotic resistance by these pathogens. AMPs exhibit a diverse spectrum of activity against bacteria, fungi, parasites, and various types of cancer. AMPs are active against various bacterial pathogens that cause disease in animals and plants. However, because of the coevolution of host and pathogen interaction, bacteria have developed the mechanisms to sense and exhibit an adaptive response against AMPs. These resistance mechanisms are playing an important role in bacterial virulence within the host. Here, we have discussed the different resistance mechanisms used by gram-positive and gram-negative bacteria to sense and combat AMP actions. Understanding the mechanism of AMP resistance may provide directions toward the development of novel therapeutic strategies to control multidrug-resistant pathogens.
Collapse
Affiliation(s)
- Piyush Baindara
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ananta K Ghosh
- Department of Biotechnology, Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Santi M Mandal
- Department of Biotechnology, Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur, India
| |
Collapse
|
17
|
Catherwood AC, Lloyd AJ, Tod JA, Chauhan S, Slade SE, Walkowiak GP, Galley NF, Punekar AS, Smart K, Rea D, Evans ND, Chappell MJ, Roper DI, Dowson CG. Substrate and Stereochemical Control of Peptidoglycan Cross-Linking by Transpeptidation by Escherichia coli PBP1B. J Am Chem Soc 2020; 142:5034-5048. [DOI: 10.1021/jacs.9b08822] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
Welsh MA, Schaefer K, Taguchi A, Kahne D, Walker S. Direction of Chain Growth and Substrate Preferences of Shape, Elongation, Division, and Sporulation-Family Peptidoglycan Glycosyltransferases. J Am Chem Soc 2019; 141:12994-12997. [PMID: 31386359 PMCID: PMC6738341 DOI: 10.1021/jacs.9b06358] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The bacterial cell wall is composed of peptidoglycan, and its biosynthesis is an established target for antibiotics. Peptidoglycan is assembled from a glycopeptide precursor, Lipid II, that is polymerized by peptidoglycan glycosyltransferases into glycan strands that are subsequently cross-linked to form the mature cell wall. For decades bacteria were thought to contain only one family of enzymes that polymerize Lipid II, but recently, the ubiquitous Shape, Elongation, Division, and Sporulation (SEDS)-family proteins RodA and FtsW were shown to be peptidoglycan polymerases. Because RodA and FtsW are essential in nearly all bacteria, these enzymes are promising targets for new antibiotics. However, almost nothing is known about the mechanisms of these polymerases. Here, we report that SEDS proteins synthesize peptidoglycan by adding new Lipid II monomers to the reducing end of the growing glycan chain. Using substrates that can only react at the reducing end, we also show that the glycosyl donor and acceptor in the polymerization reaction have distinct lipid requirements. These findings provide the first fundamental insights into the mechanism of SEDS-family polymerases and lay the groundwork for future biochemical and structural studies.
Collapse
Affiliation(s)
- Michael A. Welsh
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Kaitlin Schaefer
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Atsushi Taguchi
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| |
Collapse
|
19
|
Martinecz A, Clarelli F, Abel S, Abel Zur Wiesch P. Reaction Kinetic Models of Antibiotic Heteroresistance. Int J Mol Sci 2019; 20:E3965. [PMID: 31443146 PMCID: PMC6719119 DOI: 10.3390/ijms20163965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 11/16/2022] Open
Abstract
Bacterial heteroresistance (i.e., the co-existence of several subpopulations with different antibiotic susceptibilities) can delay the clearance of bacteria even with long antibiotic exposure. Some proposed mechanisms have been successfully described with mathematical models of drug-target binding where the mechanism's downstream of drug-target binding are not explicitly modeled and subsumed in an empirical function, connecting target occupancy to antibiotic action. However, with current approaches it is difficult to model mechanisms that involve multi-step reactions that lead to bacterial killing. Here, we have a dual aim: first, to establish pharmacodynamic models that include multi-step reaction pathways, and second, to model heteroresistance and investigate which molecular heterogeneities can lead to delayed bacterial killing. We show that simulations based on Gillespie algorithms, which have been employed to model reaction kinetics for decades, can be useful tools to model antibiotic action via multi-step reactions. We highlight the strengths and weaknesses of current models and Gillespie simulations. Finally, we show that in our models, slight normally distributed variances in the rates of any event leading to bacterial death can (depending on parameter choices) lead to delayed bacterial killing (i.e., heteroresistance). This means that a slowly declining residual bacterial population due to heteroresistance is most likely the default scenario and should be taken into account when planning treatment length.
Collapse
Affiliation(s)
- Antal Martinecz
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Fabrizio Clarelli
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Sören Abel
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
- Centre for Molecular Medicine Norway, P.O. Box 1137, Blindern, 0318 Oslo, Norway
| | - Pia Abel Zur Wiesch
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway.
- Centre for Molecular Medicine Norway, P.O. Box 1137, Blindern, 0318 Oslo, Norway.
| |
Collapse
|
20
|
Mueller EA, Egan AJ, Breukink E, Vollmer W, Levin PA. Plasticity of Escherichia coli cell wall metabolism promotes fitness and antibiotic resistance across environmental conditions. eLife 2019; 8:40754. [PMID: 30963998 PMCID: PMC6456298 DOI: 10.7554/elife.40754] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 03/23/2019] [Indexed: 11/13/2022] Open
Abstract
Although the peptidoglycan cell wall is an essential structural and morphological feature of most bacterial cells, the extracytoplasmic enzymes involved in its synthesis are frequently dispensable under standard culture conditions. By modulating a single growth parameter-extracellular pH-we discovered a subset of these so-called 'redundant' enzymes in Escherichia coli are required for maximal fitness across pH environments. Among these pH specialists are the class A penicillin binding proteins PBP1a and PBP1b; defects in these enzymes attenuate growth in alkaline and acidic conditions, respectively. Genetic, biochemical, and cytological studies demonstrate that synthase activity is required for cell wall integrity across a wide pH range and influences pH-dependent changes in resistance to cell wall active antibiotics. Altogether, our findings reveal previously thought to be redundant enzymes are instead specialized for distinct environmental niches. This specialization may ensure robust growth and cell wall integrity in a wide range of conditions. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
Collapse
Affiliation(s)
- Elizabeth A Mueller
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Alexander Jf Egan
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| |
Collapse
|
21
|
Regulation of the Peptidoglycan Polymerase Activity of PBP1b by Antagonist Actions of the Core Divisome Proteins FtsBLQ and FtsN. mBio 2019; 10:mBio.01912-18. [PMID: 30622193 PMCID: PMC6325244 DOI: 10.1128/mbio.01912-18] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Peptidoglycan (PG) is an essential constituent of the bacterial cell wall. During cell division, PG synthesis localizes at midcell under the control of a multiprotein complex, the divisome, allowing the safe formation of two new cell poles and separation of daughter cells. Genetic studies in Escherichia coli pointed out that FtsBLQ and FtsN participate in the regulation of septal PG (sPG) synthesis; however, the underlying molecular mechanisms remained largely unknown. Here we show that FtsBLQ subcomplex directly interacts with the PG synthase PBP1b and with the subcomplex FtsW-PBP3, mainly via FtsW. Strikingly, we discovered that FtsBLQ inhibits the glycosyltransferase activity of PBP1b and that this inhibition was antagonized by the PBP1b activators FtsN and LpoB. The same results were obtained in the presence of FtsW-PBP3. Moreover, using a simple thioester substrate (S2d), we showed that FtsBLQ also inhibits the transpeptidase domain of PBP3 but not of PBP1b. As the glycosyltransferase and transpeptidase activities of PBP1b are coupled and PBP3 activity requires nascent PG substrate, the results suggest that PBP1b inhibition by FtsBLQ will block sPG synthesis by these enzymes, thus maintaining cell division as repressed until the maturation of the divisome is signaled by the accumulation of FtsN, which triggers sPG synthesis and the initiation of cell constriction. These results confirm that PBP1b plays an important role in E. coli cell division and shed light on the specific role of FtsN, which seems to counterbalance the inhibitory effect of FtsBLQ to restore PBP1b activity.IMPORTANCE Bacterial cell division is governed by a multiprotein complex called divisome, which facilitates a precise cell wall synthesis at midcell and daughter cell separation. Protein-protein interactions and activity studies using different combinations of the septum synthesis core of the divisome revealed that the glycosyltransferase activity of PBP1b is repressed by FtsBLQ and that the presence of FtsN or LpoB suppresses this inhibition. Moreover, FtsBLQ also inhibits the PBP3 activity on a thioester substrate. These results provide enzymatic evidence of the regulation of the peptidoglycan synthase PBP1b and PBP3 within the divisome. The results confirm that PBP1b plays an important role in E. coli cell division and shed light on the specific role of FtsN, which functions to relieve the repression on PBP1b by FtsBLQ and to initiate septal peptidoglycan synthesis.
Collapse
|
22
|
Egan AJF, Maya-Martinez R, Ayala I, Bougault CM, Banzhaf M, Breukink E, Vollmer W, Simorre JP. Induced conformational changes activate the peptidoglycan synthase PBP1B. Mol Microbiol 2018; 110:335-356. [PMID: 30044025 PMCID: PMC6220978 DOI: 10.1111/mmi.14082] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2018] [Indexed: 12/25/2022]
Abstract
Bacteria surround their cytoplasmic membrane with an essential, stress‐bearing peptidoglycan (PG) layer consisting of glycan chains linked by short peptides into a mesh‐like structure. Growing and dividing cells expand their PG layer using inner‐membrane anchored PG synthases, including Penicillin‐binding proteins (PBPs), which participate in dynamic protein complexes to facilitate cell wall growth. In Escherichia coli, and presumably other Gram‐negative bacteria, growth of the mainly single layered PG is regulated by outer membrane‐anchored lipoproteins. The lipoprotein LpoB is required to activate PBP1B, which is a major, bi‐functional PG synthase with glycan chain polymerising (glycosyltransferase) and peptide cross‐linking (transpeptidase) activities. In this work we show how the binding of LpoB to the regulatory UB2H domain of PBP1B activates both activities. Binding induces structural changes in the UB2H domain, which transduce to the two catalytic domains by distinct allosteric pathways. We also show how an additional regulator protein, CpoB, is able to selectively modulate the TPase activation by LpoB without interfering with GTase activation.
Collapse
Affiliation(s)
- Alexander J F Egan
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Roberto Maya-Martinez
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CNRS, CEA, 71 avenue des Martyrs, 38000, Grenoble, France
| | - Isabel Ayala
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CNRS, CEA, 71 avenue des Martyrs, 38000, Grenoble, France
| | - Catherine M Bougault
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CNRS, CEA, 71 avenue des Martyrs, 38000, Grenoble, France
| | - Manuel Banzhaf
- European Molecular Biology Laboratory Heidelberg, Genome Biology Unit, Meyerhofstraße 1, 69117, Heidelberg, Germany.,Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, Birmingham , B15 2TT, UK
| | - Eefjan Breukink
- Bijvoet Center for Biomolecular Research, Department of Biochemistry of Membranes, University of Utrecht, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CNRS, CEA, 71 avenue des Martyrs, 38000, Grenoble, France
| |
Collapse
|
23
|
Martinecz A, Abel Zur Wiesch P. Estimating treatment prolongation for persistent infections. Pathog Dis 2018; 76:5068691. [PMID: 30107522 PMCID: PMC6134427 DOI: 10.1093/femspd/fty065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 08/08/2018] [Indexed: 11/12/2022] Open
Abstract
Treatment of infectious diseases is often long and requires patients to take drugs even after they have seemingly recovered. This is because of a phenomenon called persistence, which allows small fractions of the bacterial population to survive treatment despite being genetically susceptible. The surviving subpopulation is often below detection limit and therefore is empirically inaccessible but can cause treatment failure when treatment is terminated prematurely. Mathematical models could aid in predicting bacterial survival and thereby determine sufficient treatment length. However, the mechanisms of persistence are hotly debated, necessitating the development of multiple mechanistic models. Here we develop a generalized mathematical framework that can accommodate various persistence mechanisms from measurable heterogeneities in pathogen populations. It allows the estimation of the relative increase in treatment length necessary to eradicate persisters compared to the majority population. To simplify and generalize, we separate the model into two parts: the distribution of the molecular mechanism of persistence in the bacterial population (e.g. number of efflux pumps or target molecules, growth rates) and the elimination rate of single bacteria as a function of that phenotype. Thereby, we obtain an estimate of the required treatment length for each phenotypic subpopulation depending on its size and susceptibility.
Collapse
Affiliation(s)
- Antal Martinecz
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, 9037 Tromsø
| | - Pia Abel Zur Wiesch
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, 9037 Tromsø.,Centre for Molecular Medicine Norway, Nordic EMBL Partnership, P.O. Box 1137, Blindern, 0318 Oslo, Norway
| |
Collapse
|
24
|
Zeng X, Kwok JSL, Yang KY, Leung KSS, Shi M, Yang Z, Yam WC, Tsui SKW. Whole genome sequencing data of 1110 Mycobacterium tuberculosis isolates identifies insertions and deletions associated with drug resistance. BMC Genomics 2018; 19:365. [PMID: 29769016 PMCID: PMC5956929 DOI: 10.1186/s12864-018-4734-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/26/2018] [Indexed: 12/22/2022] Open
Abstract
Background Drug resistance in Mycobacterium tuberculosis (MTB) is one of the major challenges in tuberculosis (TB) treatment. However, known mutations cannot explain all of the cases of resistance and little research has focused on the relationship between insertions / deletions (indels) and drug resistance. Results Here, we retrieved whole genome sequencing data of 743 drug-resistant MTB strains and 367 pan-susceptible strains from TB patients from the public domain to identify novel genomic markers of drug resistance. A total of 20 region markers containing genes and intergenic regions (IGRs) with significant statistical correlation with antibiotic resistance were revealed, four of which have been previously reported to be associated with drug resistance. In addition, 83 point markers containing frameshift (FS) mutations and IGR indels were also identified independently based on differences in their incidence rates between drug-sensitive and -resistant strains. Among the 83 point markers, eight indels were detected in known drug-associated genes or IGRs. Furthermore, the overlap between 20 region markers and 83 point markers further indicated their associations with drug resistance. The markers identified were involved in essential bacterial metabolic functions, including cell wall and transmembrane transporter functions. A strong correlation between FS mutations and mutations in DNA repair genes including I21V in alkA, R48G in mutT4 and P2R in nth was also found. Conclusions This study identified a set of novel genetic markers with FS mutations and IGR indels associated with MTB drug resistance, which greatly broadens the pool of mutations related to MTB drug resistance. This insight may be important in identifying novel mechanisms of drug resistance in MTB. Electronic supplementary material The online version of this article (10.1186/s12864-018-4734-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Xi Zeng
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jamie Sui-Lam Kwok
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kevin Yi Yang
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kenneth Siu-Sing Leung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Mai Shi
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Zhiyuan Yang
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Wing-Cheong Yam
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Stephen Kwok-Wing Tsui
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China. .,Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR, China. .,Centre for Microbial Genomics and Proteomics, The Chinese University of Hong Kong, Hong Kong SAR, China.
| |
Collapse
|
25
|
Dhar S, Kumari H, Balasubramanian D, Mathee K. Cell-wall recycling and synthesis in Escherichia coli and Pseudomonas aeruginosa – their role in the development of resistance. J Med Microbiol 2018; 67:1-21. [DOI: 10.1099/jmm.0.000636] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Supurna Dhar
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Hansi Kumari
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | | | - Kalai Mathee
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| |
Collapse
|
26
|
PBP1B Glycosyltransferase and Transpeptidase Activities Play Different Essential Roles during the De Novo Regeneration of Rod Morphology in Escherichia coli. J Bacteriol 2017; 199:JB.00612-16. [PMID: 28096447 DOI: 10.1128/jb.00612-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/10/2017] [Indexed: 11/20/2022] Open
Abstract
Peptidoglycan is a vital component of nearly all cell wall-bearing bacteria and is a valuable target for antibacterial therapy. However, despite decades of work, there remain important gaps in understanding how this macromolecule is synthesized and molded into a three-dimensional structure that imparts specific morphologies to individual cells. Here, we investigated the particularly enigmatic area of how peptidoglycan is synthesized and shaped during the first stages of creating cell shape de novo, that is, in the absence of a preexisting template. We found that when lysozyme-induced (LI) spheroplasts of Escherichia coli were allowed to resynthesize peptidoglycan, the cells divided first and then elongated to recreate a normal rod-shaped morphology. Penicillin binding protein 1B (PBP1B) was critical for the first stage of this recovery process. PBP1B synthesized peptidoglycan de novo, and this synthesis required that PBP1B interact with the outer membrane lipoprotein LpoB. Surprisingly, when LpoB was localized improperly to the inner membrane, recovering spheroplasts synthesized peptidoglycan and divided but then propagated as amorphous spheroidal cells, suggesting that the regeneration of a normal rod shape depends on a particular spatial interaction. Similarly, spheroplasts carrying a PBP1B variant lacking transpeptidase activity or those in which PBP1A was overproduced could synthesize new peptidoglycan and divide but then grew as oddly shaped spheroids. We conclude that de novo cell wall synthesis requires the glycosyltransferase activity of PBP1B but that PBP1B transpeptidase activity is needed to assemble cell walls with wild-type morphology.IMPORTANCE Bacterial cell wall peptidoglycan is synthesized and modified by penicillin binding proteins (PBPs), which are targeted by about half of all currently prescribed antibiotics, including penicillin and its derivatives. Because antibiotic resistance is rising, it has become increasingly urgent that we fill the gaps in our knowledge about how PBPs create and assemble this protective wall. We report here that PBP1B plays an essential role in synthesizing peptidoglycan in the absence of a preexisting template: its glycosyltransferase activity is responsible for de novo synthesis, while its transpeptidase activity is required to construct cell walls of a specific shape. These results highlight the importance of this enzyme and distinguish its biological roles from those of other PBPs and peptidoglycan synthases.
Collapse
|
27
|
Egan AJF, Cleverley RM, Peters K, Lewis RJ, Vollmer W. Regulation of bacterial cell wall growth. FEBS J 2017; 284:851-867. [PMID: 27862967 DOI: 10.1111/febs.13959] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/28/2016] [Accepted: 11/09/2016] [Indexed: 12/19/2022]
Abstract
During growth and propagation, a bacterial cell enlarges and subsequently divides its peptidoglycan (PG) sacculus, a continuous mesh-like layer that encases the cell membrane to confer mechanical strength and morphological robustness. The mechanism of sacculus growth, how it is regulated and how it is coordinated with other cellular processes is poorly understood. In this article, we will discuss briefly the current knowledge of how cell wall synthesis is regulated, on multiple levels, from both sides of the cytoplasmic membrane. According to the current knowledge, cytosolic scaffolding proteins connect PG synthases with cytoskeletal elements, and protein phosphorylation regulates cell wall growth in Gram-positive species. PG-active enzymes engage in multiple protein-protein interactions within PG synthesis multienzyme complexes, and some of the interactions modulate activities. PG synthesis is also regulated by central metabolism, and by PG maturation through the action of PG hydrolytic enzymes. Only now are we beginning to appreciate how these multiple levels of regulating PG synthesis enable the cell to propagate robustly with a defined cell shape under different and variable growth conditions.
Collapse
Affiliation(s)
- Alexander J F Egan
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Robert M Cleverley
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Katharina Peters
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Richard J Lewis
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| |
Collapse
|
28
|
Interplay between Penicillin-binding proteins and SEDS proteins promotes bacterial cell wall synthesis. Sci Rep 2017; 7:43306. [PMID: 28233869 PMCID: PMC5324115 DOI: 10.1038/srep43306] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/06/2017] [Indexed: 11/14/2022] Open
Abstract
Bacteria utilize specialized multi-protein machineries to synthesize the essential peptidoglycan (PG) cell wall during growth and division. The divisome controls septal PG synthesis and separation of daughter cells. In E. coli, the lipid II transporter candidate FtsW is thought to work in concert with the PG synthases penicillin-binding proteins PBP3 and PBP1b. Yet, the exact molecular mechanisms of their function in complexes are largely unknown. We show that FtsW interacts with PBP1b and lipid II and that PBP1b, FtsW and PBP3 co-purify suggesting that they form a trimeric complex. We also show that the large loop between transmembrane helices 7 and 8 of FtsW is important for the interaction with PBP3. Moreover, we found that FtsW, but not the other flippase candidate MurJ, impairs lipid II polymerization and peptide cross-linking activities of PBP1b, and that PBP3 relieves these inhibitory effects. All together the results suggest that FtsW interacts with lipid II preventing its polymerization by PBP1b unless PBP3 is also present, indicating that PBP3 facilitates lipid II release and/or its transfer to PBP1b after transport across the cytoplasmic membrane. This tight regulatory mechanism is consistent with the cell’s need to ensure appropriate use of the limited pool of lipid II.
Collapse
|
29
|
Abel zur Wiesch P, Clarelli F, Cohen T. Using Chemical Reaction Kinetics to Predict Optimal Antibiotic Treatment Strategies. PLoS Comput Biol 2017; 13:e1005321. [PMID: 28060813 PMCID: PMC5257006 DOI: 10.1371/journal.pcbi.1005321] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 01/23/2017] [Accepted: 12/19/2016] [Indexed: 11/19/2022] Open
Abstract
Identifying optimal dosing of antibiotics has proven challenging-some antibiotics are most effective when they are administered periodically at high doses, while others work best when minimizing concentration fluctuations. Mechanistic explanations for why antibiotics differ in their optimal dosing are lacking, limiting our ability to predict optimal therapy and leading to long and costly experiments. We use mathematical models that describe both bacterial growth and intracellular antibiotic-target binding to investigate the effects of fluctuating antibiotic concentrations on individual bacterial cells and bacterial populations. We show that physicochemical parameters, e.g. the rate of drug transmembrane diffusion and the antibiotic-target complex half-life are sufficient to explain which treatment strategy is most effective. If the drug-target complex dissociates rapidly, the antibiotic must be kept constantly at a concentration that prevents bacterial replication. If antibiotics cross bacterial cell envelopes slowly to reach their target, there is a delay in the onset of action that may be reduced by increasing initial antibiotic concentration. Finally, slow drug-target dissociation and slow diffusion out of cells act to prolong antibiotic effects, thereby allowing for less frequent dosing. Our model can be used as a tool in the rational design of treatment for bacterial infections. It is easily adaptable to other biological systems, e.g. HIV, malaria and cancer, where the effects of physiological fluctuations of drug concentration are also poorly understood.
Collapse
Affiliation(s)
- Pia Abel zur Wiesch
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, Oslo, Norway
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
| | - Fabrizio Clarelli
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway
| | - Ted Cohen
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| |
Collapse
|
30
|
van't Veer IL, Leloup NOL, Egan AJF, Janssen BJC, Martin NI, Vollmer W, Breukink E. Site-Specific Immobilization of the Peptidoglycan Synthase PBP1B on a Surface Plasmon Resonance Chip Surface. Chembiochem 2016; 17:2250-2256. [PMID: 27709766 PMCID: PMC5298014 DOI: 10.1002/cbic.201600461] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Indexed: 12/23/2022]
Abstract
Surface plasmon resonance (SPR) is one of the most powerful label-free methods to determine the kinetic parameters of molecular interactions in real time and in a highly sensitive way. Penicillin-binding proteins (PBPs) are peptidoglycan synthesis enzymes present in most bacteria. Established protocols to analyze interactions of PBPs by SPR involve immobilization to an ampicillin-coated chip surface (a β-lactam antibiotic mimicking its substrate), thereby forming a covalent complex with the PBPs transpeptidase (TP) active site. However, PBP interactions measured with a substrate-bound TP domain potentially affect interactions near the TPase active site. Furthermore, in vivo PBPs are anchored in the inner membrane by an N-terminal transmembrane helix, and hence immobilization at the C-terminal TPase domain gives an orientation contrary to the in vivo situation. We designed a new procedure: immobilization of PBP by copper-free click chemistry at an azide incorporated in the N terminus. In a proof-of-principle study, we immobilized Escherichia coli PBP1B on an SPR chip surface and used this for the analysis of the well-characterized interaction of PBP1B with LpoB. The site-specific incorporation of the azide affords control over protein orientation, thereby resulting in a homogeneous immobilization on the chip surface. This method can be used to study topology-dependent interactions of any (membrane) protein.
Collapse
Affiliation(s)
- Inge L. van't Veer
- Department of Membrane Biochemistry and BiophysicsUtrecht UniversityPadualaan 83584 CHUtrechtThe Netherlands
| | - Nadia O. L. Leloup
- Crystal and Structural ChemistryUtrecht UniversityPadualaan 83584 CHUtrechtThe Netherlands
| | - Alexander J. F. Egan
- The Centre for Bacterial Cell BiologyNewcastle UniversityRichardson RoadNE2 4AX, Newcastle upon TyneUK
| | - Bert J. C. Janssen
- Crystal and Structural ChemistryUtrecht UniversityPadualaan 83584 CHUtrechtThe Netherlands
| | - Nathaniel I. Martin
- Department of Chemical Biology and Drug DiscoveryUtrecht Institute for Pharmaceutical SciencesUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Waldemar Vollmer
- The Centre for Bacterial Cell BiologyNewcastle UniversityRichardson RoadNE2 4AX, Newcastle upon TyneUK
| | - Eefjan Breukink
- Department of Membrane Biochemistry and BiophysicsUtrecht UniversityPadualaan 83584 CHUtrechtThe Netherlands
| |
Collapse
|
31
|
Hugonnet JE, Mengin-Lecreulx D, Monton A, den Blaauwen T, Carbonnelle E, Veckerlé C, Brun YV, van Nieuwenhze M, Bouchier C, Tu K, Rice LB, Arthur M. Factors essential for L,D-transpeptidase-mediated peptidoglycan cross-linking and β-lactam resistance in Escherichia coli. eLife 2016; 5. [PMID: 27767957 PMCID: PMC5089857 DOI: 10.7554/elife.19469] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/20/2016] [Indexed: 12/04/2022] Open
Abstract
The target of β-lactam antibiotics is the D,D-transpeptidase activity of penicillin-binding proteins (PBPs) for synthesis of 4→3 cross-links in the peptidoglycan of bacterial cell walls. Unusual 3→3 cross-links formed by L,D-transpeptidases were first detected in Escherichia coli more than four decades ago, however no phenotype has previously been associated with their synthesis. Here we show that production of the L,D-transpeptidase YcbB in combination with elevated synthesis of the (p)ppGpp alarmone by RelA lead to full bypass of the D,D-transpeptidase activity of PBPs and to broad-spectrum β-lactam resistance. Production of YcbB was therefore sufficient to switch the role of (p)ppGpp from antibiotic tolerance to high-level β-lactam resistance. This observation identifies a new mode of peptidoglycan polymerization in E. coli that relies on an unexpectedly small number of enzyme activities comprising the glycosyltransferase activity of class A PBP1b and the D,D-carboxypeptidase activity of DacA in addition to the L,D-transpeptidase activity of YcbB. DOI:http://dx.doi.org/10.7554/eLife.19469.001
Collapse
Affiliation(s)
- Jean-Emmanuel Hugonnet
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
| | - Dominique Mengin-Lecreulx
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Alejandro Monton
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Etienne Carbonnelle
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
| | - Carole Veckerlé
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
| | | | | | | | - Kuyek Tu
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
| | - Louis B Rice
- Rhode Island Hospital, Brown University, Providence, United States
| | - Michel Arthur
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
| |
Collapse
|
32
|
Becucci L, Toppi A, Fiore A, Scaloni A, Guidelli R. Channel-forming activity of syringopeptin 25A in mercury-supported phospholipid monolayers and negatively charged bilayers. Bioelectrochemistry 2016; 111:131-42. [DOI: 10.1016/j.bioelechem.2016.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/10/2016] [Accepted: 06/12/2016] [Indexed: 11/15/2022]
|
33
|
The Membrane Steps of Bacterial Cell Wall Synthesis as Antibiotic Targets. Antibiotics (Basel) 2016; 5:antibiotics5030028. [PMID: 27571111 PMCID: PMC5039524 DOI: 10.3390/antibiotics5030028] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 11/23/2022] Open
Abstract
Peptidoglycan is the major component of the cell envelope of virtually all bacteria. It has structural roles and acts as a selective sieve for molecules from the outer environment. Peptidoglycan synthesis is therefore one of the most important biogenesis pathways in bacteria and has been studied extensively over the last twenty years. The pathway starts in the cytoplasm, continues in the cytoplasmic membrane and finishes in the periplasmic space, where the precursor is polymerized into the peptidoglycan layer. A number of proteins involved in this pathway, such as the Mur enzymes and the penicillin binding proteins (PBPs), have been studied and regarded as good targets for antibiotics. The present review focuses on the membrane steps of peptidoglycan synthesis that involve two enzymes, MraY and MurG, the inhibitors of these enzymes and the inhibition mechanisms. We also discuss the challenges of targeting these two cytoplasmic membrane (associated) proteins in bacterial cells and the perspectives on how to overcome the issues.
Collapse
|
34
|
Urem M, Świątek-Połatyńska MA, Rigali S, van Wezel GP. Intertwining nutrient-sensory networks and the control of antibiotic production inStreptomyces. Mol Microbiol 2016; 102:183-195. [DOI: 10.1111/mmi.13464] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Mia Urem
- Molecular Biotechnology, Institute of Biology, Leiden University; Sylviusweg 72 Leiden 2333BE The Netherlands
| | - Magdalena A. Świątek-Połatyńska
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology; Karl-von-Frisch-Strasse 10 Marburg 35043 Germany
| | - Sébastien Rigali
- InBioS, Centre for Protein Engineering; University of Liège; Liège B-4000 Belgium
| | - Gilles P. van Wezel
- Molecular Biotechnology, Institute of Biology, Leiden University; Sylviusweg 72 Leiden 2333BE The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW); Droevendaalsesteeg 10 Wageningen 6708 PB The Netherlands
| |
Collapse
|
35
|
Auer GK, Lee TK, Rajendram M, Cesar S, Miguel A, Huang KC, Weibel DB. Mechanical Genomics Identifies Diverse Modulators of Bacterial Cell Stiffness. Cell Syst 2016; 2:402-11. [PMID: 27321372 PMCID: PMC4967499 DOI: 10.1016/j.cels.2016.05.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 02/03/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
Bacteria must maintain mechanical integrity to withstand the large osmotic pressure differential across the cell membrane and wall. Although maintaining mechanical integrity is critical for proper cellular function, a fact exploited by prominent cell-wall-targeting antibiotics, the proteins that contribute to cellular mechanics remain unidentified. Here, we describe a high-throughput optical method for quantifying cell stiffness and apply this technique to a genome-wide collection of ∼4,000 Escherichia coli mutants. We identify genes with roles in diverse functional processes spanning cell-wall synthesis, energy production, and DNA replication and repair that significantly change cell stiffness when deleted. We observe that proteins with biochemically redundant roles in cell-wall synthesis exhibit different stiffness defects when deleted. Correlating our data with chemical screens reveals that reducing membrane potential generally increases cell stiffness. In total, our work demonstrates that bacterial cell stiffness is a property of both the cell wall and broader cell physiology and lays the groundwork for future systematic studies of mechanoregulation.
Collapse
Affiliation(s)
- George K Auer
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Timothy K Lee
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Manohary Rajendram
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Spencer Cesar
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amanda Miguel
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Douglas B Weibel
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
36
|
Glycosyltransferases and Transpeptidases/Penicillin-Binding Proteins: Valuable Targets for New Antibacterials. Antibiotics (Basel) 2016; 5:antibiotics5010012. [PMID: 27025527 PMCID: PMC4810414 DOI: 10.3390/antibiotics5010012] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 01/27/2016] [Accepted: 02/03/2016] [Indexed: 12/29/2022] Open
Abstract
Peptidoglycan (PG) is an essential macromolecular sacculus surrounding most bacteria. It is assembled by the glycosyltransferase (GT) and transpeptidase (TP) activities of multimodular penicillin-binding proteins (PBPs) within multiprotein complex machineries. Both activities are essential for the synthesis of a functional stress-bearing PG shell. Although good progress has been made in terms of the functional and structural understanding of GT, finding a clinically useful antibiotic against them has been challenging until now. In contrast, the TP/PBP module has been successfully targeted by β-lactam derivatives, but the extensive use of these antibiotics has selected resistant bacterial strains that employ a wide variety of mechanisms to escape the lethal action of these antibiotics. In addition to traditional β-lactams, other classes of molecules (non-β-lactams) that inhibit PBPs are now emerging, opening new perspectives for tackling the resistance problem while taking advantage of these valuable targets, for which a wealth of structural and functional knowledge has been accumulated. The overall evidence shows that PBPs are part of multiprotein machineries whose activities are modulated by cofactors. Perturbation of these systems could lead to lethal effects. Developing screening strategies to take advantage of these mechanisms could lead to new inhibitors of PG assembly. In this paper, we present a general background on the GTs and TPs/PBPs, a survey of recent issues of bacterial resistance and a review of recent works describing new inhibitors of these enzymes.
Collapse
|
37
|
Abel Zur Wiesch P, Abel S, Gkotzis S, Ocampo P, Engelstädter J, Hinkley T, Magnus C, Waldor MK, Udekwu K, Cohen T. Classic reaction kinetics can explain complex patterns of antibiotic action. Sci Transl Med 2016; 7:287ra73. [PMID: 25972005 DOI: 10.1126/scitranslmed.aaa8760] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Finding optimal dosing strategies for treating bacterial infections is extremely difficult, and improving therapy requires costly and time-intensive experiments. To date, an incomplete mechanistic understanding of drug effects has limited our ability to make accurate quantitative predictions of drug-mediated bacterial killing and impeded the rational design of antibiotic treatment strategies. Three poorly understood phenomena complicate predictions of antibiotic activity: post-antibiotic growth suppression, density-dependent antibiotic effects, and persister cell formation. We show that chemical binding kinetics alone are sufficient to explain these three phenomena, using single-cell data and time-kill curves of Escherichia coli and Vibrio cholerae exposed to a variety of antibiotics in combination with a theoretical model that links chemical reaction kinetics to bacterial population biology. Our model reproduces existing observations, has a high predictive power across different experimental setups (R(2) = 0.86), and makes several testable predictions, which we verified in new experiments and by analyzing published data from a clinical trial on tuberculosis therapy. Although a variety of biological mechanisms have previously been invoked to explain post-antibiotic growth suppression, density-dependent antibiotic effects, and especially persister cell formation, our findings reveal that a simple model that considers only binding kinetics provides a parsimonious and unifying explanation for these three complex, phenotypically distinct behaviours. Current antibiotic and other chemotherapeutic regimens are often based on trial and error or expert opinion. Our "chemical reaction kinetics"-based approach may inform new strategies, which are based on rational design.
Collapse
Affiliation(s)
- Pia Abel Zur Wiesch
- Division of Global Health Equity, Brigham and Women's Hospital and Harvard Medical School, 641 Huntington Avenue, Boston, MA 02115, USA. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510, USA.
| | - Sören Abel
- Division of Infectious Diseases, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA. Department of Pharmacy, UiT, The Arctic University of Norway, 9037 Tromsø, Norway
| | - Spyridon Gkotzis
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177 Stockholm, Sweden
| | - Paolo Ocampo
- Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland. Department of Environmental Microbiology, EAWAG, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - Jan Engelstädter
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Trevor Hinkley
- School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Carsten Magnus
- Institute of Medical Virology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA. Howard Hughes Medical Institute, 181 Longwood Avenue, Boston, MA 02115, USA
| | - Klas Udekwu
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177 Stockholm, Sweden
| | - Ted Cohen
- Division of Global Health Equity, Brigham and Women's Hospital and Harvard Medical School, 641 Huntington Avenue, Boston, MA 02115, USA. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510, USA. Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
| |
Collapse
|
38
|
Egan AJF, Vollmer W. Continuous Fluorescence Assay for Peptidoglycan Glycosyltransferases. Methods Mol Biol 2016; 1440:171-84. [PMID: 27311672 DOI: 10.1007/978-1-4939-3676-2_13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bacterial cell wall peptidoglycan is synthesized from its precursor lipid II by two enzymatic reactions. First, glycosyltransferases polymerize the glycan strands and second, DD-transpeptidases form cross-links between peptides of neighboring strands. Most bacteria possess bifunctional peptidoglycan synthesis enzymes capable of catalyzing both reactions. Here, we describe a continuous fluorescence glycosyltransferase assay using Dansyl-labeled lipid II as substrate. Progression of the reaction is monitored by the reduction in fluorescence over time. The assay is suitable to investigate the effect of protein interaction partners on the glycan strand synthesis activity of peptidoglycan polymerases.
Collapse
Affiliation(s)
- Alexander J F Egan
- Institute for Cell and Molecular Biosciences, The Centre for Bacterial Cell Biology, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| | - Waldemar Vollmer
- Institute for Cell and Molecular Biosciences, The Centre for Bacterial Cell Biology, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| |
Collapse
|
39
|
Sosič I, Anderluh M, Sova M, Gobec M, Mlinarič Raščan I, Derouaux A, Amoroso A, Terrak M, Breukink E, Gobec S. Structure-Activity Relationships of Novel Tryptamine-Based Inhibitors of Bacterial Transglycosylase. J Med Chem 2015; 58:9712-21. [PMID: 26588190 DOI: 10.1021/acs.jmedchem.5b01482] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Penicillin-binding proteins represent well-established, validated, and still very promising targets for the design and development of new antibacterial agents. The transglycosylase domain of penicillin-binding proteins is especially important, as it catalyzes polymerization of glycan chains, using the peptidoglycan precursor lipid II as a substrate. On the basis of the previous discovery of a noncovalent small-molecule inhibitor of transglycosylase activity, we systematically explored the structure-activity relationships of these tryptamine-based inhibitors. The main aim was to reduce the nonspecific cytotoxic properties of the initial hit compound and concurrently to retain the mode of its inhibition. A focused library of tryptamine-based compounds was synthesized, characterized, and evaluated biochemically. The results presented here show the successful reduction of the nonspecific cytotoxicity, and the retention of the inhibition of transglycosylase enzymatic activity, as well as the ability of these compounds to bind to lipid II and to have antibacterial actions.
Collapse
Affiliation(s)
- Izidor Sosič
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Marko Anderluh
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Matej Sova
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Martina Gobec
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Irena Mlinarič Raščan
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Adeline Derouaux
- Centre d'Ingénierie des Protéines, Université de Liège , Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Ana Amoroso
- Centre d'Ingénierie des Protéines, Université de Liège , Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Mohammed Terrak
- Centre d'Ingénierie des Protéines, Université de Liège , Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Eefjan Breukink
- Department Biochemistry of Membranes, Bijvoet Centre, Institute of Biomembranes, Utrecht University , Utrecht 3584 CH, The Netherlands
| | - Stanislav Gobec
- Faculty of Pharmacy, University of Ljubljana , Aškerčeva 7, 1000 Ljubljana, Slovenia
| |
Collapse
|
40
|
Egan AJF, Biboy J, van't Veer I, Breukink E, Vollmer W. Activities and regulation of peptidoglycan synthases. Philos Trans R Soc Lond B Biol Sci 2015; 370:20150031. [PMID: 26370943 PMCID: PMC4632607 DOI: 10.1098/rstb.2015.0031] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2015] [Indexed: 12/22/2022] Open
Abstract
Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have been studied for 70 years, useful in vitro assays for measuring their activities were established only recently, and these provided the first insights into the regulation of these enzymes. Here, we review the current knowledge on the glycosyltransferase and transpeptidase activities of PG synthases. We provide new data showing that the bifunctional PBP1A and PBP1B from Escherichia coli are active upon reconstitution into the membrane environment of proteoliposomes, and that these enzymes also exhibit DD-carboxypeptidase activity in certain conditions. Both novel features are relevant for their functioning within the cell. We also review recent data on the impact of protein-protein interactions and other factors on the activities of PBPs. As an example, we demonstrate a synergistic effect of multiple protein-protein interactions on the glycosyltransferase activity of PBP1B, by its cognate lipoprotein activator LpoB and the essential cell division protein FtsN.
Collapse
Affiliation(s)
- Alexander J F Egan
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne NE2 4AX, UK
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne NE2 4AX, UK
| | - Inge van't Veer
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, University of Utrecht, Padualaan 8, 3584 Utrecht, The Netherlands
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, University of Utrecht, Padualaan 8, 3584 Utrecht, The Netherlands
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne NE2 4AX, UK
| |
Collapse
|
41
|
Kieser KJ, Boutte CC, Kester JC, Baer CE, Barczak AK, Meniche X, Chao MC, Rego EH, Sassetti CM, Fortune SM, Rubin EJ. Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria. PLoS Pathog 2015; 11:e1005010. [PMID: 26114871 PMCID: PMC4483258 DOI: 10.1371/journal.ppat.1005010] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 06/07/2015] [Indexed: 01/11/2023] Open
Abstract
Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP) capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG), is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1’s catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress. Bacterial infections rely on continued bacterial growth. Studying cell growth is particularly important for pathogens such as Mycobacterium tuberculosis that grow differently than model organisms. Unlike Escherichia coli or Bacillus subtilis, which grow by incorporating cell wall material along their body, mycobacteria grow from the pole. It remains unclear how mycobacteria construct and extend their poles. Our work identifies a cell wall synthase, PonA1, as a key determinant of mycobacterial polar growth. PonA1 governs polar growth through two enzymatic activities that build the cell wall’s peptidoglycan (PG); both of these activities are required for normal cell growth. Changes in the amount or activity of PonA1 leads to misplaced cell poles and inhibition of cell proliferation. PonA1 is phosphorylated, an unusual modification for PG synthases. This phosphorylation tunes the rate of cell elongation. Changing PonA1’s regulatory or enzymatic activity impacts the survival of cells in the host or when treated with antibiotics. Our work shows how mycobacterial cell pole construction and cell fitness is governed by a major cell wall synthase; these findings may have implications for other bacteria that elongate from their poles.
Collapse
Affiliation(s)
- Karen J. Kieser
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Cara C. Boutte
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Jemila C. Kester
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Christina E. Baer
- Department of Microbiology and Physiological Systems, Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Amy K. Barczak
- Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Xavier Meniche
- Department of Microbiology and Physiological Systems, Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Michael C. Chao
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - E. Hesper Rego
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Christopher M. Sassetti
- Department of Microbiology and Physiological Systems, Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Sarah M. Fortune
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Eric J. Rubin
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
42
|
Abstract
The dramatic rise in the incidence of antibiotic resistance demands that new therapeutic options will have to be developed. One potentially interesting class of antimicrobials are the modified bacteriocins termed lantibiotics, which are bacterially produced, posttranslationally modified, lanthionine/methyllanthionine-containing peptides. It is interesting that low levels of resistance have been reported for lantibiotics compared with commercial antibiotics. Given that there are very few examples of naturally occurring lantibiotic resistance, attempts have been made to deliberately induce resistance phenotypes in order to investigate this phenomenon. Mechanisms that hinder the action of lantibiotics are often innate systems that react to the presence of any cationic peptides/proteins or ones which result from cell well damage, rather than being lantibiotic specific. Such resistance mechanisms often arise due to altered gene regulation following detection of antimicrobials/cell wall damage by sensory proteins at the membrane. This facilitates alterations to the cell wall or changes in the composition of the membrane. Other general forms of resistance include the formation of spores or biofilms, which are a common mechanistic response to many classes of antimicrobials. In rare cases, bacteria have been shown to possess specific antilantibiotic mechanisms. These are often species specific and include the nisin lytic protein nisinase and the phenomenon of immune mimicry.
Collapse
Affiliation(s)
- Lorraine A Draper
- School of Microbiology, University College Cork, Cork, Ireland Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Paul D Cotter
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - Colin Hill
- School of Microbiology, University College Cork, Cork, Ireland Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - R Paul Ross
- School of Microbiology, University College Cork, Cork, Ireland Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| |
Collapse
|
43
|
Gray AN, Egan AJF, Van't Veer IL, Verheul J, Colavin A, Koumoutsi A, Biboy J, Altelaar AFM, Damen MJ, Huang KC, Simorre JP, Breukink E, den Blaauwen T, Typas A, Gross CA, Vollmer W. Coordination of peptidoglycan synthesis and outer membrane constriction during Escherichia coli cell division. eLife 2015; 4. [PMID: 25951518 PMCID: PMC4458516 DOI: 10.7554/elife.07118] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/06/2015] [Indexed: 02/04/2023] Open
Abstract
To maintain cellular structure and integrity during division, Gram-negative bacteria must carefully coordinate constriction of a tripartite cell envelope of inner membrane, peptidoglycan (PG), and outer membrane (OM). It has remained enigmatic how this is accomplished. Here, we show that envelope machines facilitating septal PG synthesis (PBP1B-LpoB complex) and OM constriction (Tol system) are physically and functionally coordinated via YbgF, renamed CpoB (Coordinator of PG synthesis and OM constriction, associated with PBP1B). CpoB localizes to the septum concurrent with PBP1B-LpoB and Tol at the onset of constriction, interacts with both complexes, and regulates PBP1B activity in response to Tol energy state. This coordination links PG synthesis with OM invagination and imparts a unique mode of bifunctional PG synthase regulation by selectively modulating PBP1B cross-linking activity. Coordination of the PBP1B and Tol machines by CpoB contributes to effective PBP1B function in vivo and maintenance of cell envelope integrity during division. DOI:http://dx.doi.org/10.7554/eLife.07118.001 All bacterial cells are surrounded by a membrane, which forms a protective barrier around the cell. Most bacteria also have a wall surrounding the membrane, which provides structural support. When a bacterial cell divides to produce two daughter cells, it produces a belt-like structure around the middle of the cell. This brings the membrane and cell wall on each side together to a ‘pinch-point’ until the two halves of the cell have been separated. This process must be carefully controlled to ensure that the cell does not burst open at any point. Some bacteria known as ‘Gram-negative’ bacteria have a second membrane on the other side of the cell wall. These cells divide in the same way as other bacteria, but the need to coordinate the movement of three structures instead of two makes it more complicated. Many proteins are known to be involved. For example, one group (or ‘complex’) of proteins—which includes a protein called PBP1B—helps to produce new cell wall material. Another complex called the Tol system provides the energy needed for the outer membrane to be pulled inwards towards the pinch point. However, it has not been clear how these complexes work together to allow the cell to divide. Here, Gray, Egan et al. searched for proteins that can interact with PBP1B during cell division in the Gram-negative bacterium E. coli. The experiments found that a protein called CpoB interacts with both PBP1B and the Tol system. CpoB is found in a band around the middle of the cell, and it regulates the activity of PBP1B in response to signals from the Tol system. If the activity of CpoB is disrupted, cell wall production and the movement of the outer membrane are no longer coordinated, and the membrane falls apart, leading to the death of the bacteria. Gray, Egan et al.'s findings show how the production of new cell wall material can be linked to the inwards movement of the outer membrane during cell division. The next challenges are to understand the precise details of how these processes are coordinated by CpoB and to find out whether CpoB also plays the same role in other bacteria. DOI:http://dx.doi.org/10.7554/eLife.07118.002
Collapse
Affiliation(s)
- Andrew N Gray
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Alexander J F Egan
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Inge L Van't Veer
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, University of Utrecht, Utrecht, The Netherlands
| | - Jolanda Verheul
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Alexandra Koumoutsi
- Genome Biology Unit, European Molecular Biology Laboratory Heidelberg, Heidelberg, Germany
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - A F Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands
| | - Mirjam J Damen
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands
| | | | - Jean-Pierre Simorre
- Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Bijvoet Centre for Biomolecular Research, University of Utrecht, Utrecht, The Netherlands
| | - Tanneke den Blaauwen
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Athanasios Typas
- Genome Biology Unit, European Molecular Biology Laboratory Heidelberg, Heidelberg, Germany
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| |
Collapse
|
44
|
Bury D, Dahmane I, Derouaux A, Dumbre S, Herdewijn P, Matagne A, Breukink E, Mueller-Seitz E, Petz M, Terrak M. Positive cooperativity between acceptor and donor sites of the peptidoglycan glycosyltransferase. Biochem Pharmacol 2014; 93:141-50. [PMID: 25462814 DOI: 10.1016/j.bcp.2014.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/07/2014] [Accepted: 11/07/2014] [Indexed: 12/01/2022]
Abstract
The glycosyltransferases of family 51 (GT51) catalyze the polymerization of lipid II to form linear glycan chains, which, after cross linking by the transpeptidases, form the net-like peptidoglycan macromolecule. The essential function of the GT makes it an attractive antimicrobial target; therefore a better understanding of its function and its mechanism of interaction with substrates could help in the design and the development of new antibiotics. In this work, we have used a surface plasmon resonance Biacore(®) biosensor, based on an amine derivative of moenomycin A immobilized on a sensor chip surface, to investigate the mechanism of binding of substrate analogous inhibitors to the GT. Addition of increasing concentrations of moenomycin A to the Staphylococcus aureus MtgA led to reduced binding of the protein to the sensor chip as expected. Remarkably, in the presence of low concentrations of the most active disaccharide inhibitors, binding of MtgA to immobilized moenomycin A was found to increase; in contrast competition with moenomycin A occurred only at high concentrations. This finding suggests that at low concentrations, the lipid II analogs bind to the acceptor site and induce a cooperative binding of moenomycin A to the donor site. Our results constitute the first indication of the existence of a positive cooperativity between the acceptor and the donor sites of peptidoglycan GTs. In addition, our study indicates that a modification of two residues (L119N and F120S) within the hydrophobic region of MtgA can yield monodisperse forms of the protein with apparently no change in its secondary structure content, but this is at the expense of the enzyme function.
Collapse
Affiliation(s)
- Daniel Bury
- Department of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany.
| | - Ismahene Dahmane
- Centre d'Ingénierie des Protéines, Université de Liège, Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Adeline Derouaux
- Centre d'Ingénierie des Protéines, Université de Liège, Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Shrinivas Dumbre
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - Piet Herdewijn
- Laboratory of Medicinal Chemistry, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium
| | - André Matagne
- Centre d'Ingénierie des Protéines, Université de Liège, Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Erika Mueller-Seitz
- Department of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany
| | - Michael Petz
- Department of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany
| | - Mohammed Terrak
- Centre d'Ingénierie des Protéines, Université de Liège, Allée de la Chimie, B6a, B-4000, Sart Tilman, Liège, Belgium.
| |
Collapse
|
45
|
Braddick D, Sandhu S, Roper DI, Chappell MJ, Bugg TDH. Observation of the time-course for peptidoglycan lipid intermediate II polymerization by Staphylococcus aureus monofunctional transglycosylase. MICROBIOLOGY-SGM 2014; 160:1628-1636. [PMID: 24858082 DOI: 10.1099/mic.0.079442-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The polymerization of lipid intermediate II by the transglycosylase activity of penicillin-binding proteins (PBPs) represents an important target for antibacterial action, but limited methods are available for quantitative assay of this reaction, or screening potential inhibitors. A new labelling method for lipid II polymerization products using Sanger's reagent (fluoro-2,4-dinitrobenzene), followed by gel permeation HPLC analysis, has permitted the observation of intermediate polymerization products for Staphylococcus aureus monofunctional transglycosylase MGT. Peak formation is inhibited by 6 µM ramoplanin or enduracidin. Characterization by mass spectrometry indicates the formation of tetrasaccharide and octasaccharide intermediates, but not a hexasaccharide intermediate, suggesting a dimerization of a lipid-linked tetrasaccharide. Numerical modelling of the time-course data supports a kinetic model involving addition to lipid-linked tetrasaccharide of either lipid II or lipid-linked tetrasaccharide. Observation of free octasaccharide suggests that hydrolysis of the undecaprenyl diphosphate lipid carrier occurs at this stage in peptidoglycan transglycosylation.
Collapse
Affiliation(s)
- Darren Braddick
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Sandeep Sandhu
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - David I Roper
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | | | - Timothy D H Bugg
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| |
Collapse
|
46
|
Galley NF, O'Reilly AM, Roper DI. Prospects for novel inhibitors of peptidoglycan transglycosylases. Bioorg Chem 2014; 55:16-26. [PMID: 24924926 PMCID: PMC4126109 DOI: 10.1016/j.bioorg.2014.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/12/2014] [Accepted: 05/12/2014] [Indexed: 01/07/2023]
Abstract
We examine key aspects of transglycosylase inhibitor design. Low to high throughput assays suitable for transglycosylase drug discovery. Existing chemical start points for transglycosylase active site targeting.
The lack of novel antimicrobial drugs under development coupled with the increasing occurrence of resistance to existing antibiotics by community and hospital acquired infections is of grave concern. The targeting of biosynthesis of the peptidoglycan component of the bacterial cell wall has proven to be clinically valuable but relatively little therapeutic development has been directed towards the transglycosylase step of this process. Advances towards the isolation of new antimicrobials that target transglycosylase activity will rely on the development of the enzymological tools required to identify and characterise novel inhibitors of these enzymes. Therefore, in this article, we review the assay methods developed for transglycosylases and review recent novel chemical inhibitors discovered in relation to both the lipidic substrates and natural product inhibitors of the transglycosylase step.
Collapse
Affiliation(s)
- Nicola F Galley
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Amy M O'Reilly
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - David I Roper
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.
| |
Collapse
|
47
|
Arguelles Arias A, Ongena M, Devreese B, Terrak M, Joris B, Fickers P. Characterization of amylolysin, a novel lantibiotic from Bacillus amyloliquefaciens GA1. PLoS One 2013; 8:e83037. [PMID: 24349428 PMCID: PMC3857288 DOI: 10.1371/journal.pone.0083037] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 10/30/2013] [Indexed: 11/18/2022] Open
Abstract
Background Lantibiotics are heat-stable peptides characterized by the presence of thioether amino acid lanthionine and methyllanthionine. They are capable to inhibit the growth of Gram-positive bacteria, including Listeria monocytogenes, Staphylococcus aureus or Bacillus cereus, the causative agents of food-borne diseases or nosocomial infections. Lantibiotic biosynthetic machinery is encoded by gene cluster composed by a structural gene that codes for a pre-lantibiotic peptide and other genes involved in pre-lantibiotic modifications, regulation, export and immunity. Methodology/Findings Bacillus amyloliquefaciens GA1 was found to produce an antimicrobial peptide, named amylolysin, active on an array of Gram-positive bacteria, including methicillin resistant S. aureus. Genome characterization led to the identification of a putative lantibiotic gene cluster that comprises a structural gene (amlA) and genes involved in modification (amlM), transport (amlT), regulation (amlKR) and immunity (amlFE). Disruption of amlA led to loss of biological activity, confirming thus that the identified gene cluster is related to amylolysin synthesis. MALDI-TOF and LC-MS analysis on purified amylolysin demonstrated that this latter corresponds to a novel lantibiotic not described to date. The ability of amylolysin to interact invitro with the lipid II, the carrier of peptidoglycan monomers across the cytoplasmic membrane and the presence of a unique modification gene suggest that the identified peptide belongs to the group B lantibiotic. Amylolysin immunity seems to be driven by only two AmlF and AmlE proteins, which is uncommon within the Bacillus genus. Conclusion/Significance Apart from mersacidin produced by Bacillus amyloliquefaciens strains Y2 and HIL Y-85,544728, reports on the synthesis of type B-lantibiotic in this species are scarce. This study reports on a genetic and structural characterization of another representative of the type B lantibiotic in B. amyloliquefaciens.
Collapse
Affiliation(s)
- Anthony Arguelles Arias
- Centre d'Ingénierie des Protéines, Bacterial Physiology and Genetics, Université de Liège, Liège, Belgium
| | - Marc Ongena
- Centre Wallon de Biologie Industrielle, Unité de Bioindustrie, Faculté de Sciences Agronomique de Gembloux, Gembloux, Belgium
| | - Bart Devreese
- Laboratorium voor Eiwitbiochemie en Eiwitengineering, Universiteit-Gent, Gent, Belgium
| | - Mohammed Terrak
- Centre d'Ingénierie des Protéines, Bacterial Physiology and Genetics, Université de Liège, Liège, Belgium
| | - Bernard Joris
- Centre d'Ingénierie des Protéines, Bacterial Physiology and Genetics, Université de Liège, Liège, Belgium
| | - Patrick Fickers
- Unité de Biotechnologies et Bioprocédés, Université Libre de Bruxelles, Brussels, Belgium
- * E-mail:
| |
Collapse
|
48
|
Huang SH, Wu WS, Huang LY, Huang WF, Fu WC, Chen PT, Fang JM, Cheng WC, Cheng TJR, Wong CH. New continuous fluorometric assay for bacterial transglycosylase using Förster resonance energy transfer. J Am Chem Soc 2013; 135:17078-89. [PMID: 24131464 DOI: 10.1021/ja407985m] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The emergence of antibiotic resistance has prompted scientists to search for new antibiotics. Transglycosylase (TGase) is an attractive target for new antibiotic discovery due to its location on the outer membrane of bacteria and its essential role in peptidoglycan synthesis. Though there have been a few molecules identified as TGase inhibitors in the past thirty years, none of them have been developed into antibiotics for humans. The slow pace of development is perhaps due to the lack of continuous, quantitative, and high-throughput assay available for the enzyme. Herein, we report a new continuous fluorescent assay based on Förster resonance energy transfer, using lipid II analogues with a dimethylamino-azobenzenesulfonyl quencher in the lipid chain and a coumarin fluorophore in the peptide chain. During the process of transglycosylation, the quencher-appended polyprenol is released and the fluorescence of coumarin can be detected. Using this system, the substrate specificity and affinity of lipid II analogues bearing various numbers and configurations of isoprene units were investigated. Moreover, the inhibition constants of moenomycin and two previously identified small molecules were also determined. In addition, a high-throughput screening using the new assay was conducted to identify potent TGase inhibitors from a 120,000 compound library. This new continuous fluorescent assay not only provides an efficient and convenient way to study TGase activities, but also enables the high-throughput screening of potential TGase inhibitors for antibiotic discovery.
Collapse
Affiliation(s)
- Shih-Hsien Huang
- Genomics Research Center, Academia Sinica , 128 Academia Road, Section 2, Nankang, Taipei, 115, Taiwan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Hughes HV, Lisher JP, Hardy GG, Kysela DT, Arnold RJ, Giedroc DP, Brun YV. Co-ordinate synthesis and protein localization in a bacterial organelle by the action of a penicillin-binding-protein. Mol Microbiol 2013; 90:1162-77. [PMID: 24118129 DOI: 10.1111/mmi.12422] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2013] [Indexed: 11/29/2022]
Abstract
Organelles with specialized form and function occur in diverse bacteria. Within the Alphaproteobacteria, several species extrude thin cellular appendages known as stalks, which function in nutrient uptake, buoyancy and reproduction. Consistent with their specialization, stalks maintain a unique molecular composition compared with the cell body, but how this is achieved remains to be fully elucidated. Here we dissect the mechanism of localization of StpX, a stalk-specific protein in Caulobacter crescentus. Using a forward genetics approach, we identify a penicillin-binding-protein, PbpC, which is required for the localization of StpX in the stalk. We show that PbpC acts at the stalked cell pole to anchor StpX to rigid components of the outer membrane of the elongating stalk, concurrent with stalk synthesis. Stalk-localized StpX in turn functions in cellular responses to copper and zinc, suggesting that the stalk may contribute to metal homeostasis in Caulobacter. Together, these results identify a novel role for a penicillin-binding-protein in compartmentalizing a bacterial organelle it itself helps create, raising the possibility that cell wall-synthetic enzymes may broadly serve not only to synthesize the diverse shapes of bacteria, but also to functionalize them at the molecular level.
Collapse
Affiliation(s)
- H Velocity Hughes
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Derouaux A, Sauvage E, Terrak M. Peptidoglycan glycosyltransferase substrate mimics as templates for the design of new antibacterial drugs. Front Immunol 2013; 4:78. [PMID: 23543824 PMCID: PMC3608906 DOI: 10.3389/fimmu.2013.00078] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 03/13/2013] [Indexed: 12/02/2022] Open
Abstract
Peptidoglycan (PG) is an essential net-like macromolecule that surrounds bacteria, gives them their shape, and protects them against their own high osmotic pressure. PG synthesis inhibition leads to bacterial cell lysis, making it an important target for many antibiotics. The final two reactions in PG synthesis are performed by penicillin-binding proteins (PBPs). Their glycosyltransferase (GT) activity uses the lipid II precursor to synthesize glycan chains and their transpeptidase (TP) activity catalyzes the cross-linking of two glycan chains via the peptide side chains. Inhibition of either of these two reactions leads to bacterial cell death. β-lactam antibiotics target the transpeptidation reaction while antibiotic therapy based on inhibition of the GTs remains to be developed. Ongoing research is trying to fill this gap by studying the interactions of GTs with inhibitors and substrate mimics and utilizing the latter as templates for the design of new antibiotics. In this review we present an updated overview on the GTs and describe the structure-activity relationship of recently developed synthetic ligands.
Collapse
Affiliation(s)
- Adeline Derouaux
- Centre d'Ingénierie des Protéines, University of Liège Liège, Belgium
| | | | | |
Collapse
|