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Mahieu L, González-González A, Rubio-Meléndez ME, Moya-Hernández M, Francis F, Ramírez CC. An Aphid Pest Superclone Benefits From a Facultative Bacterial Endosymbiont in a Host-Dependent Manner, Leading to Reproductive and Proteomic Changes. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 117:e22154. [PMID: 39397367 DOI: 10.1002/arch.22154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 09/05/2024] [Accepted: 09/21/2024] [Indexed: 10/15/2024]
Abstract
The English grain aphid, Sitobion avenae, is a significant agricultural pest affecting wheat, barley, and oats. In Chile, the most prevalent and persistent clone (superclone) of S. avenae harbors the facultative endosymbiont bacterium Regiella insecticola. To determine the role of this bacterium in the reproductive success of this superclone, the presence of R. insecticola was manipulated to assess its impact on (1) the reproductive performance of this clone on two host plant species (wheat and barley), (2) the production of winged morphs, (3) changes in the insects' proteomic profiles, and (4) the root/shoot ratio of plant. It was found that the reproductive performance of this S. avenae superclone varied across host plants, depending on the presence of the facultative bacterial endosymbiont. Aphids infected with R. insecticola showed higher reproductive success on wheat, while the opposite effect was observed on barley. Aphid biomass was greater when infected with R. insecticola, particularly on barley. Additionally, aphids harboring R. insecticola exhibited a higher proportion of winged individuals on both host plants. Protein regulation in aphids on wheat was lower compared to those on barley. A higher root/shoot biomass ratio was observed in wheat plants compared to barley when infested by R. insecticola-infected aphid. Thus, R. insecticola significantly influences the reproductive performance and proteomic profile of a S. avenae superclone, with these effects shaped by the host plant. This suggests that the interaction between the host plant and the facultative endosymbiont contributes to the ecological success of this superclone.
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Affiliation(s)
- Leandro Mahieu
- Gembloux Agro-Bio Tech-Université de Liège, Gembloux, Belgium
| | - Angélica González-González
- Centre for Molecular and Functional Ecology, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - María Eugenia Rubio-Meléndez
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, Talca, Maule, Chile
| | - Mario Moya-Hernández
- Centre for Molecular and Functional Ecology, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | | | - Claudio C Ramírez
- Centre for Molecular and Functional Ecology, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
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Gong H, Yan D, Cui Y, Li Y, Yang J, Yang W, Zhan R, Wan Q, Wang X, He H, Chen X, Lutkenhaus J, Yang X, Du S. The divisome is a self-enhancing machine in Escherichia coli and Caulobacter crescentus. Nat Commun 2024; 15:8198. [PMID: 39294118 PMCID: PMC11410940 DOI: 10.1038/s41467-024-52217-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 08/27/2024] [Indexed: 09/20/2024] Open
Abstract
During bacterial cytokinesis, polymers of the bacterial tubulin FtsZ coalesce into the Z ring to orchestrate divisome assembly and septal cell wall synthesis. Previous studies have found that Z ring condensation and stability is critical for successful cell division. However, how FtsZ filaments condense into a Z ring remains enigmatic and whether septal cell wall synthesis can feedback to the Z ring has not been investigated. Here, we show that FtsZ-associated proteins (Zaps) play important roles in Z ring condensation and stability, and discover septal cell wall synthesis as a novel player for Z ring condensation and stabilization in Escherichia coli and Caulobacter crescentus. Moreover, we find that the interaction between the Z ring membrane anchor, FtsA, and components of the septal cell wall synthetic complex are critical for septal cell wall synthesis-mediated Z ring condensation. Altogether, these findings suggest that the divisome is a self-enhancing machine in these two gram-negative bacteria, where the Z ring and the septal cell wall synthetic complex communicate with and reinforce each other to ensure robustness of cell division.
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Affiliation(s)
- Han Gong
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
- Key Laboratory of Polar Environment Monitoring and Public Governance (Ministry of Education), Wuhan University, Wuhan, China
| | - Di Yan
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Yuanyuan Cui
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Ying Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Jize Yang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Wenjie Yang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Rui Zhan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Qianqian Wan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Xinci Wang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Haofeng He
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Xiangdong Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Joe Lutkenhaus
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Xinxing Yang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
| | - Shishen Du
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
- Key Laboratory of Polar Environment Monitoring and Public Governance (Ministry of Education), Wuhan University, Wuhan, China.
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Simpson BW, McLean AB, Trent MS. A conserved hub protein for coordinating peptidoglycan turnover that activates cell division amidases in Acinetobacter baumannii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.11.612460. [PMID: 39314424 PMCID: PMC11419085 DOI: 10.1101/2024.09.11.612460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Gram-negative bacteria produce a multilayered cell envelope in which their peptidoglycan is sandwiched between two membranes, an inner membrane made of glycerophospholipids and an asymmetric outer membrane with glycerophospholipids in the inner leaflet and lipopolysaccharide (LPS) in the outer leaflet. The Acinetobacter baumannii outer membrane contains lipooligosaccharide (LOS), a variant of LPS lacking O-antigen. LPS/LOS is typically essential, but A. baumannii can survive without LOS. Previously, we found that the peptidoglycan biogenesis protein NlpD becomes essential during LOS-deficiency. NlpD is typically redundant and is one of the cell's amidase activators for regulating peptidoglycan degradation, a process critical for cell division. We found that NlpD is essential under these conditions because a second putative amidase activator, termed WthA (cell w all turnover h ub protein A ), no longer functions in LOS-deficient cells. Mutants lacking WthA had severe cell division defects and were synthetically sick with loss of NlpD. Both Acinetobacter WthA and NlpD were found to activate an amidase activity of Oxa51, a chromosomally encoded β -lactamase. Further, WthA is homologous to Pseudomonas LbcA that impacts two other classes of peptidoglycan degradation enzymes, endopeptidases and lytic transglycosylases. WthA/LbcA homologs were identified across Proteobacteria, Bacteroidota, and Chlorobiota, suggesting they belong to a conserved family involved in regulation of peptidoglycan turnover. While Acinetobacter WthA may share functions of Pseudomonas LbcA, we found no evidence that LbcA is an amidase activator. Altogether, we have identified a missing player in Acinetobacter peptidoglycan biogenesis, a conserved hub protein that regulates multiple peptidoglycan turnover enzymes including cell division amidases. Significance Statement Peptidoglycan is a rigid layer that provides structural support to bacterial cells. Peptidoglycan must be degraded to make room for new synthesis and for cells to divide, a process termed turnover. Turnover enzymes are tightly regulated to prevent their activities from lysing the cell. The critical pathogen Acinetobacter baumannii was missing known peptidoglycan amidases, a class of turnover enzymes, and the key activator that controls their activity during cell division. We have identified WthA as having a role in cell division most likely as an amidase activator. WthA homologs were widely distributed in bacteria and the closely related LbcA in Pseudomonas impacts two other types of turnover enzymes. We explore the possible functions of this new family of proteins that serves as a hub for impacting peptidoglycan turnover.
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Son JE, Park SH, Choi U, Lee CR. Lytic transglycosylase repertoire diversity enables intrinsic antibiotic resistance and daughter cell separation in Escherichia coli under acidic stress. Antimicrob Agents Chemother 2024; 68:e0037224. [PMID: 38884456 PMCID: PMC11232391 DOI: 10.1128/aac.00372-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/21/2024] [Indexed: 06/18/2024] Open
Abstract
Peptidoglycan (PG) is an important architectural element that imparts physical toughness and rigidity to the bacterial envelope. It is also a dynamic structure that undergoes continuous turnover or autolysis. Escherichia coli possesses redundant PG degradation enzymes responsible for PG turnover; however, the advantage afforded by the existence of numerous PG degradation enzymes remains incompletely understood. In this study, we elucidated the physiological roles of MltE and MltC, members of the lytic transglycosylase (LTG) family that catalyze the cleavage of glycosidic bonds between disaccharide subunits within PG strands. MltE and MltC are acidic LTGs that exhibit increased enzymatic activity and protein levels under acidic pH conditions, respectively, and deletion of these two LTGs results in a pronounced growth defect at acidic pH. Furthermore, inactivation of these two LTGs induces increased susceptibility at acidic pH against various antibiotics, particularly vancomycin, which seems to be partially caused by elevated membrane permeability. Intriguingly, inactivation of these LTGs induces a chaining morphology, indicative of daughter cell separation defects, only under acidic pH conditions. Simultaneous deletion of PG amidases, known contributors to daughter cell separation, exacerbates the chaining phenotype at acidic pH. This suggests that the two LTGs may participate in the cleavage of glycan strands between daughter cells under acidic pH conditions. Collectively, our findings highlight the role of LTG repertoire diversity in facilitating bacterial survival and antibiotic resistance under stressful conditions.
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Affiliation(s)
- Ji Eun Son
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Si Hyoung Park
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Umji Choi
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
| | - Chang-Ro Lee
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido, Republic of Korea
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Alcorlo M, Martínez-Caballero S, Li J, Sham LT, Luo M, Hermoso JA. Modulation of the lytic apparatus by the FtsEX complex within the bacterial division machinery. FEBS Lett 2024. [PMID: 38849310 DOI: 10.1002/1873-3468.14953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/09/2024]
Abstract
The FtsEX membrane complex constitutes an essential component of the ABC transporter superfamily, widely distributed among bacterial species. It governs peptidoglycan degradation for cell division, acting as a signal transmitter rather than a substrate transporter. Through the ATPase activity of FtsE, it facilitates signal transmission from the cytosol across the membrane to the periplasm, activating associated peptidoglycan hydrolases. This review concentrates on the latest structural advancements elucidating the architecture of the FtsEX complex and its interplay with lytic enzymes or regulatory counterparts. The revealed three-dimensional structures unveil a landscape wherein a precise array of intermolecular interactions, preserved across diverse bacterial species, afford meticulous spatial and temporal control over the cell division process.
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Affiliation(s)
- Martín Alcorlo
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Jianwei Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Department of Biological Sciences, Center for Bioimaging Sciences, National University of Singapore, Singapore
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme and Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Min Luo
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
- Department of Biological Sciences, Center for Bioimaging Sciences, National University of Singapore, Singapore
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain
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Chen Y, Gu J, Yang B, Yang L, Pang J, Luo Q, Li Y, Li D, Deng Z, Dong C, Dong H, Zhang Z. Structure and activity of the septal peptidoglycan hydrolysis machinery crucial for bacterial cell division. PLoS Biol 2024; 22:e3002628. [PMID: 38814940 PMCID: PMC11139282 DOI: 10.1371/journal.pbio.3002628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 04/14/2024] [Indexed: 06/01/2024] Open
Abstract
The peptidoglycan (PG) layer is a critical component of the bacterial cell wall and serves as an important target for antibiotics in both gram-negative and gram-positive bacteria. The hydrolysis of septal PG (sPG) is a crucial step of bacterial cell division, facilitated by FtsEX through an amidase activation system. In this study, we present the cryo-EM structures of Escherichia coli FtsEX and FtsEX-EnvC in the ATP-bound state at resolutions of 3.05 Å and 3.11 Å, respectively. Our PG degradation assays in E. coli reveal that the ATP-bound conformation of FtsEX activates sPG hydrolysis of EnvC-AmiB, whereas EnvC-AmiB alone exhibits autoinhibition. Structural analyses indicate that ATP binding induces conformational changes in FtsEX-EnvC, leading to significant differences from the apo state. Furthermore, PG degradation assays of AmiB mutants confirm that the regulation of AmiB by FtsEX-EnvC is achieved through the interaction between EnvC-AmiB. These findings not only provide structural insight into the mechanism of sPG hydrolysis and bacterial cell division, but also have implications for the development of novel therapeutics targeting drug-resistant bacteria.
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Affiliation(s)
- Yatian Chen
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Jiayue Gu
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Biao Yang
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Lili Yang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Jie Pang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Qinghua Luo
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yirong Li
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Danyang Li
- The Cryo-EM Center, Core facility of Wuhan University, Wuhan University, Wuhan, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Changjiang Dong
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
| | - Haohao Dong
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Zhengyu Zhang
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, Wuhan, China
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Alodaini D, Hernandez-Rocamora V, Boelter G, Ma X, Alao MB, Doherty HM, Bryant JA, Moynihan P, Moradigaravand D, Glinkowska M, Vollmer W, Banzhaf M. Reduced peptidoglycan synthesis capacity impairs growth of E. coli at high salt concentration. mBio 2024; 15:e0032524. [PMID: 38426748 PMCID: PMC11005333 DOI: 10.1128/mbio.00325-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 02/13/2024] [Indexed: 03/02/2024] Open
Abstract
Gram-negative bacteria have a thin peptidoglycan layer between the cytoplasmic and outer membranes protecting the cell from osmotic challenges. Hydrolases of this structure are needed to cleave bonds to allow the newly synthesized peptidoglycan strands to be inserted by synthases. These enzymes need to be tightly regulated and their activities coordinated to prevent cell lysis. To better understand this process in Escherichia coli, we probed the genetic interactions of mrcA (encodes PBP1A) and mrcB (encodes PBP1B) with genes encoding peptidoglycan amidases and endopeptidases in envelope stress conditions. Our extensive genetic interaction network analysis revealed relatively few combinations of hydrolase gene deletions with reduced fitness in the absence of PBP1A or PBP1B, showing that none of the amidases or endopeptidases is strictly required for the functioning of one of the class A PBPs. This illustrates the robustness of the peptidoglycan growth mechanism. However, we discovered that the fitness of ∆mrcB cells is significantly reduced under high salt stress and in vitro activity assays suggest that this phenotype is caused by a reduced peptidoglycan synthesis activity of PBP1A at high salt concentration.IMPORTANCEEscherichia coli and many other bacteria have a surprisingly high number of peptidoglycan hydrolases. These enzymes function in concert with synthases to facilitate the expansion of the peptidoglycan sacculus under a range of growth and stress conditions. The synthases PBP1A and PBP1B both contribute to peptidoglycan expansion during cell division and growth. Our genetic interaction analysis revealed that these two penicillin-binding proteins (PBPs) do not need specific amidases, endopeptidases, or lytic transglycosylases for function. We show that PBP1A and PBP1B do not work equally well when cells encounter high salt stress and demonstrate that PBP1A alone cannot provide sufficient PG synthesis activity under this condition. These results show how the two class A PBPs and peptidoglycan hydrolases govern cell envelope integrity in E. coli in response to environmental challenges and particularly highlight the importance of PBP1B in maintaining cell fitness under high salt conditions.
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Affiliation(s)
- Dema Alodaini
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Victor Hernandez-Rocamora
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gabriela Boelter
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Xuyu Ma
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Micheal B. Alao
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Hannah M. Doherty
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jack A. Bryant
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Patrick Moynihan
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Danesh Moradigaravand
- KAUST Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Makkah, Saudi Arabia
- Laboratory for Infectious Disease Epidemiology, KAUST Smart-Health Initiative and Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Makkah, Saudi Arabia
| | - Monika Glinkowska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Waldemar Vollmer
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Manuel Banzhaf
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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8
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Modi M, Thambiraja M, Cherukat A, Yennamalli RM, Priyadarshini R. Structure predictions and functional insights into Amidase_3 domain containing N-acetylmuramyl-L-alanine amidases from Deinococcus indicus DR1. BMC Microbiol 2024; 24:101. [PMID: 38532329 DOI: 10.1186/s12866-024-03225-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/15/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND N-acetylmuramyl-L-alanine amidases are cell wall modifying enzymes that cleave the amide bond between the sugar residues and stem peptide in peptidoglycan. Amidases play a vital role in septal cell wall cleavage and help separate daughter cells during cell division. Most amidases are zinc metalloenzymes, and E. coli cells lacking amidases grow as chains with daughter cells attached to each other. In this study, we have characterized two amidase enzymes from Deinococcus indicus DR1. D. indicus DR1 is known for its high arsenic tolerance and unique cell envelope. However, details of their cell wall biogenesis remain largely unexplored. RESULTS We have characterized two amidases Ami1Di and Ami2Di from D. indicus DR1. Both Ami1Di and Ami2Di suppress cell separation defects in E. coli amidase mutants, suggesting that these enzymes are able to cleave septal cell wall. Ami1Di and Ami2Di proteins possess the Amidase_3 catalytic domain with conserved -GHGG- motif and Zn2+ binding sites. Zn2+- binding in Ami1Di is crucial for amidase activity. AlphaFold2 structures of both Ami1Di and Ami2Di were predicted, and Ami1Di was a closer homolog to AmiA of E. coli. CONCLUSION Our results indicate that Ami1Di and Ami2Di enzymes can cleave peptidoglycan, and structural prediction studies revealed insights into the activity and regulation of these enzymes in D. indicus DR1.
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Affiliation(s)
- Malvika Modi
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India
| | - Menaka Thambiraja
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India
| | - Archana Cherukat
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India
- Department of Biology, Graduate School of Arts and Sciences, Wake Forest University, 1834 Wake Forest Rd, Winston-Salem, USA
| | - Ragothaman M Yennamalli
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, 613401, India
| | - Richa Priyadarshini
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, 201314, India.
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9
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Hao A, Suo Y, Lee SY. Structural insights into the FtsEX-EnvC complex regulation on septal peptidoglycan hydrolysis in Vibrio cholerae. Structure 2024; 32:188-199.e5. [PMID: 38070498 DOI: 10.1016/j.str.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/02/2023] [Accepted: 11/14/2023] [Indexed: 02/04/2024]
Abstract
During bacterial cell division, hydrolysis of septal peptidoglycan (sPG) is crucial for cell separation. This sPG hydrolysis is performed by the enzyme amidases whose activity is regulated by the integral membrane protein complex FtsEX-EnvC. FtsEX is an ATP-binding cassette transporter, and EnvC is a long coiled-coil protein that interacts with and activates the amidases. The molecular mechanism by which the FtsEX-EnvC complex activates amidases remains largely unclear. We present the cryo-electron microscopy structure of the FtsEX-EnvC complex from the pathogenic bacteria V. cholerae (FtsEX-EnvCVC). FtsEX-EnvCVC in the presence of ADP adopts a distinct conformation where EnvC is "horizontally extended" rather than "vertically extended". Subsequent structural studies suggest that EnvC can swing between these conformations in space in a nucleotide-dependent manner. Our structural analysis and functional studies suggest that FtsEX-EnvCVC employs spatial control of EnvC for amidase activation, providing mechanistic insights into the FtsEX-EnvC regulation on septal peptidoglycan hydrolysis.
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Affiliation(s)
- Aili Hao
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Yang Suo
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
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10
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Bibek GC, Zhou P, Wu C. A New Method for Gene Deletion to Investigate Cell Wall Biogenesis in Fusobacterium nucleatum. Methods Mol Biol 2024; 2727:69-82. [PMID: 37815709 DOI: 10.1007/978-1-0716-3491-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
Controlled septal peptidoglycan hydrolysis is vital for bacterial cell division, preserving cellular integrity and facilitating proper daughter cell separation. In Escherichia coli, the FtsEX ABC system governs cell wall hydrolase activation by regulating the EnvC activator. However, the processes underlying cell division in the Gram-negative oral bacterium Fusobacterium nucleatum are poorly understood, mainly due to its well-known genetic intractability. Herein, we provide a step-by-step procedure for a new gene deletion method in F. nucleatum, focusing on the ftsX gene as a target. This novel approach exploits the HicAB toxin-antitoxin system, using HicA as a counter-selective marker to enable efficient and precise gene deletion. By implementing this technique, we successfully demonstrated its applicability in F. nucleatum, providing new insights into this important microorganism's cell division process. Furthermore, this advanced gene deletion technique offers a valuable resource for future investigation into the functional characterization of genes involved in cell wall biogenesis in F. nucleatum and other genetically intractable microorganisms.
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Affiliation(s)
- G C Bibek
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, TX, USA
| | - Peng Zhou
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, TX, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, TX, USA.
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11
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Li J, Xu X, Shi J, Hermoso JA, Sham LT, Luo M. Regulation of the cell division hydrolase RipC by the FtsEX system in Mycobacterium tuberculosis. Nat Commun 2023; 14:7999. [PMID: 38044344 PMCID: PMC10694151 DOI: 10.1038/s41467-023-43770-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 11/17/2023] [Indexed: 12/05/2023] Open
Abstract
The FtsEX complex regulates, directly or via a protein mediator depending on bacterial genera, peptidoglycan degradation for cell division. In mycobacteria and Gram-positive bacteria, the FtsEX system directly activates peptidoglycan-hydrolases by a mechanism that remains unclear. Here we report our investigation of Mycobacterium tuberculosis FtsEX as a non-canonical regulator with high basal ATPase activity. The cryo-EM structures of the FtsEX system alone and in complex with RipC, as well as the ATP-activated state, unveil detailed information on the signal transduction mechanism, leading to the activation of RipC. Our findings indicate that RipC is recognized through a "Match and Fit" mechanism, resulting in an asymmetric rearrangement of the extracellular domains of FtsX and a unique inclined binding mode of RipC. This study provides insights into the molecular mechanisms of FtsEX and RipC regulation in the context of a critical human pathogen, guiding the design of drugs targeting peptidoglycan remodeling.
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Affiliation(s)
- Jianwei Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Xin Xu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Jian Shi
- Center for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Blas Cabrera", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme and Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
| | - Min Luo
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore.
- Center for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
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12
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Zhu L, Liang J, Zheng Y, Chen S, Xu Q, Yin S, Hong Y, Cao W, Lai W, Gong Z. Combined mutations of the penA with ftsX genes contribute to ceftriaxone resistance in Neisseria gonorrhoeae and peptide nucleic acids targeting these genes reverse ceftriaxone resistance. J Glob Antimicrob Resist 2023; 35:19-25. [PMID: 37567469 DOI: 10.1016/j.jgar.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/26/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
OBJECTIVES To investigate the gene mutations associated with ceftriaxone (CRO) resistance among gonococcal isolates, and to determine the effects of the mutated genes on CRO minimum inhibitory concentrations (MICs) with transformation assays and antisense peptide nucleic acids (asPNAs). METHODS Ceftriaxone-resistant (CROR) and ceftriaxone-susceptible (CROS) isolates were identified using EUCAST and paired according to similarity in their MICs to other antimicrobials. The two groups of gonococci were sequenced and analysed. Mutated genes that showed a statistical difference between the two groups were transformed into gonococcal reference strains to determine their functions. AsPNAs were designed and transformed into the former transformant to further confirm the effects of the mutated genes. RESULTS Twenty-two paired CROR and CROS isolates were obtained. The incidence of the penA-A501T and penA-G542S mutations individually, as well as combined mutations (penA-A501T and ftsX-R251H, penA-G542S and ftsX R251H), was statistically different between the two groups. The MIC of ATCC43069 (A43) increased 2 times following transformation with penA-A501T, and the MICs of A43 and ATCC49226 (A49) increased 32 times and 2 times following transformation with penA-A501T and ftsX-R251H, respectively. Antisense PNA-P3 reduced the MIC of the A43 transformant most significantly when transformed individually. PNA-P3 and PNA-F1 (asPNAs of the penA and ftsX) restored CRO susceptibility. CONCLUSIONS PenA-A501T and penA-G542S mutations are important in CRO resistance among gonococci isolates. The ftsX-R251H mutation is also related to CRO resistance, and combined mutations of ftsX-R251H and penA-A501T comediate a significant reduction in CRO susceptibility. The combined application of PNA-P3 and PNA-F1 could effectively reverse the resistance to CRO in N. gonorrhoeae.
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Affiliation(s)
- Lin Zhu
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Jingyao Liang
- Department of Dermatology, Guangzhou Institute of Dermatology, Guangzhou, China
| | - Yue Zheng
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Shaochun Chen
- Institute of Dermatology and Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - Qingfang Xu
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Songchao Yin
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Yiyong Hong
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Wenling Cao
- Department of Dermatology, Guangzhou Institute of Dermatology, Guangzhou, China
| | - Wei Lai
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Zijian Gong
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
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13
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G C B, Zhou P, Naha A, Gu J, Wu C. Development of a xylose-inducible promoter and riboswitch combination system for manipulating gene expression in Fusobacterium nucleatum. Appl Environ Microbiol 2023; 89:e0066723. [PMID: 37695289 PMCID: PMC10537658 DOI: 10.1128/aem.00667-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/05/2023] [Indexed: 09/12/2023] Open
Abstract
Inducible gene expression systems are important for studying bacterial gene function, yet most exhibit leakage. In this study, we engineered a leakage-free hybrid system for precise gene expression controls in Fusobacterium nucleatum by integrating the xylose-inducible expression system with the theophylline-responsive riboswitch. This innovative method enables concurrent control of target gene expression at both transcription and translation initiation levels. Using luciferase and the indole-producing enzyme tryptophanase (TnaA) as reporters, we demonstrated that the hybrid system displays virtually no observable signal in the absence of inducers. We employed this system to express FtsX, a protein related to fusobacterial cytokinesis, in an ftsX mutant strain, unveiling a dose-dependent manner in FtsX production. Without inducers, cells form long filaments, while increasing FtsX levels by increasing inducer concentrations led to a gradual reduction in cell length until normal morphology was restored. Crucially, this system facilitated essential gene investigation, identifying the signal peptidase lepB gene as vital for F. nucleatum. LepB's essentiality stems from depletion, affecting outer membrane biogenesis and cell division. This novel hybrid system holds the potential for advancing research on essential genes and accurate gene regulation in F. nucleatum. IMPORTANCE Fusobacterium nucleatum, an anaerobic bacterium prevalent in the human oral cavity, is strongly linked to periodontitis and can colonize areas beyond the oral cavity, such as the placenta and gastrointestinal tract, causing adverse pregnancy outcomes and promoting colorectal cancer growth. Given F. nucleatum's clinical significance, research is underway to develop targeted therapies to inhibit its growth or eradicate the bacterium specifically. Essential genes, crucial for bacterial survival, growth, and reproduction, are promising drug targets. A leak-free-inducible gene expression system is needed for studying these genes, enabling conditional gene knockouts and elucidating the importance of those essential genes. Our study identified lepB as the essential gene by first generating a conditional gene mutation in F. nucleatum. Combining a xylose-inducible system with a riboswitch facilitated the analysis of essential genes in F. nucleatum, paving the way for potential drug development targeting this bacterium for various clinical applications.
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Affiliation(s)
- Bibek G C
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Peng Zhou
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Arindam Naha
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Jianhua Gu
- Houston Methodist Hospital Research Institute, Houston, Texas, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
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14
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Izquierdo-Martinez A, Billini M, Miguel-Ruano V, Hernández-Tamayo R, Richter P, Biboy J, Batuecas MT, Glatter T, Vollmer W, Graumann PL, Hermoso JA, Thanbichler M. DipM controls multiple autolysins and mediates a regulatory feedback loop promoting cell constriction in Caulobacter crescentus. Nat Commun 2023; 14:4095. [PMID: 37433794 DOI: 10.1038/s41467-023-39783-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 06/22/2023] [Indexed: 07/13/2023] Open
Abstract
Proteins with a catalytically inactive LytM-type endopeptidase domain are important regulators of cell wall-degrading enzymes in bacteria. Here, we study their representative DipM, a factor promoting cell division in Caulobacter crescentus. We show that the LytM domain of DipM interacts with multiple autolysins, including the soluble lytic transglycosylases SdpA and SdpB, the amidase AmiC and the putative carboxypeptidase CrbA, and stimulates the activities of SdpA and AmiC. Its crystal structure reveals a conserved groove, which is predicted to represent the docking site for autolysins by modeling studies. Mutations in this groove indeed abolish the function of DipM in vivo and its interaction with AmiC and SdpA in vitro. Notably, DipM and its targets SdpA and SdpB stimulate each other's recruitment to midcell, establishing a self-reinforcing cycle that gradually increases autolytic activity as cytokinesis progresses. DipM thus coordinates different peptidoglycan-remodeling pathways to ensure proper cell constriction and daughter cell separation.
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Affiliation(s)
- Adrian Izquierdo-Martinez
- Department of Biology, University of Marburg, Marburg, Germany
- Max Planck Fellow Group Bacterial Cell Biology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Maria Billini
- Department of Biology, University of Marburg, Marburg, Germany
| | - Vega Miguel-Ruano
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Rogelio Hernández-Tamayo
- Department of Chemistry, University of Marburg, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Pia Richter
- Department of Biology, University of Marburg, Marburg, Germany
| | - Jacob Biboy
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - María T Batuecas
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Timo Glatter
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Peter L Graumann
- Department of Chemistry, University of Marburg, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Martin Thanbichler
- Department of Biology, University of Marburg, Marburg, Germany.
- Max Planck Fellow Group Bacterial Cell Biology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany.
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15
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Mallik S, Dodia H, Ghosh A, Srinivasan R, Good L, Raghav SK, Beuria TK. FtsE, the Nucleotide Binding Domain of the ABC Transporter Homolog FtsEX, Regulates Septal PG Synthesis in E. coli. Microbiol Spectr 2023; 11:e0286322. [PMID: 37014250 PMCID: PMC10269673 DOI: 10.1128/spectrum.02863-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/11/2023] [Indexed: 04/05/2023] Open
Abstract
The peptidoglycan (PG) layer, a crucial component of the tripartite E.coli envelope, is required to maintain cellular integrity, protecting the cells from mechanical stress resulting from intracellular turgor pressure. Thus, coordinating synthesis and hydrolysis of PG during cell division (septal PG) is crucial for bacteria. The FtsEX complex directs septal PG hydrolysis through the activation of amidases; however, the mechanism and regulation of septal PG synthesis are unclear. In addition, how septal PG synthesis and hydrolysis are coordinated has remained unclear. Here, we have shown that overexpression of FtsE leads to a mid-cell bulging phenotype in E.coli, which is different from the filamentous phenotype observed during overexpression of other cell division proteins. Silencing of the common PG synthesis genes murA and murB reduced bulging, confirming that this phenotype is due to excess PG synthesis. We further demonstrated that septal PG synthesis is independent of FtsE ATPase activity and FtsX. These observations and previous results suggest that FtsEX plays a role during septal PG hydrolysis, whereas FtsE alone coordinates septal PG synthesis. Overall, our study findings support a model in which FtsE plays a role in coordinating septal PG synthesis with bacterial cell division. IMPORTANCE The peptidoglycan (PG) layer is an essential component of the E.coli envelope that is required to maintain cellular shape and integrity. Thus, coordinating PG synthesis and hydrolysis at the mid-cell (septal PG) is crucial during bacterial division. The FtsEX complex directs septal PG hydrolysis through the activation of amidases; however, its role in regulation of septal PG synthesis is unclear. Here, we demonstrate that overexpression of FtsE in E.coli leads to a mid-cell bulging phenotype due to excess PG synthesis. This phenotype was reduced upon silencing of common PG synthesis genes murA and murB. We further demonstrated that septal PG synthesis is independent of FtsE ATPase activity and FtsX. These observations suggest that the FtsEX complex plays a role during septal PG hydrolysis, whereas FtsE alone coordinates septal PG synthesis. Our study indicates that FtsE plays a role in coordinating septal PG synthesis with bacterial cell division.
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Affiliation(s)
- Sunanda Mallik
- Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Hiren Dodia
- Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha, India
- Regional Centre for Biotechnology, Faridabad, Haryana, India
| | - Arup Ghosh
- Institute of Life Sciences, Nalco Square, Bhubaneswar, Odisha, India
| | - Ramanujam Srinivasan
- National Institute of Science Education and Research, Bhubaneswar, Odisha, India
| | - Liam Good
- The Royal Veterinary College, University of London, London, United Kingdom
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16
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Xu X, Li J, Chua WZ, Pages MA, Shi J, Hermoso JA, Bernhardt T, Sham LT, Luo M. Mechanistic insights into the regulation of cell wall hydrolysis by FtsEX and EnvC at the bacterial division site. Proc Natl Acad Sci U S A 2023; 120:e2301897120. [PMID: 37186861 PMCID: PMC10214136 DOI: 10.1073/pnas.2301897120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/08/2023] [Indexed: 05/17/2023] Open
Abstract
The peptidoglycan (PG) cell wall produced by the bacterial division machinery is initially shared between the daughters and must be split to promote cell separation and complete division. In gram-negative bacteria, enzymes that cleave PG called amidases play major roles in the separation process. To prevent spurious cell wall cleavage that can lead to cell lysis, amidases like AmiB are autoinhibited by a regulatory helix. Autoinhibition is relieved at the division site by the activator EnvC, which is in turn regulated by the ATP-binding cassette (ABC) transporter-like complex called FtsEX. EnvC is also known to be autoinhibited by a regulatory helix (RH), but how its activity is modulated by FtsEX and the mechanism by which it activates the amidases have remained unclear. Here, we investigated this regulation by determining the structure of Pseudomonas aeruginosa FtsEX alone with or without bound ATP, in complex with EnvC, and in a FtsEX-EnvC-AmiB supercomplex. In combination with biochemical studies, the structures reveal that ATP binding is likely to activate FtsEX-EnvC and promote its association with AmiB. Furthermore, the AmiB activation mechanism is shown to involve a RH rearrangement. In the activated state of the complex, the inhibitory helix of EnvC is released, freeing it to associate with the RH of AmiB, which liberates its active site for PG cleavage. These regulatory helices are found in many EnvC proteins and amidases throughout gram-negative bacteria, suggesting that the activation mechanism is broadly conserved and a potential target for lysis-inducing antibiotics that misregulate the complex.
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Affiliation(s)
- Xin Xu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore117543
| | - Jianwei Li
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore117543
| | - Wan-Zhen Chua
- Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117545, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117545, Singapore
| | - Martin A. Pages
- Department of Crystallography and Structural Biology, Instituto de Química-Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Madrid28006, Spain
| | - Jian Shi
- Center for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore117543
| | - Juan A. Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Madrid28006, Spain
| | - Thomas Bernhardt
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA02115
- HHMI, MA02115, Boston
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117545, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117545, Singapore
| | - Min Luo
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore117543
- Center for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore117543
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17
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Bibek GC, Zhou P, Naha A, Gu J, Wu C. Development of a Xylose-Inducible Promoter and Riboswitch Combination System for Manipulating Gene Expression in Fusobacterium nucleatum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538132. [PMID: 37163003 PMCID: PMC10168284 DOI: 10.1101/2023.04.24.538132] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Inducible gene expression systems are important for studying bacterial gene function, yet most exhibit leakage. In this study, we engineered a leakage-free hybrid system for precise gene expression controls in Fusobacterium nucleatum by integrating the xylose-inducible expression system with the theophylline-responsive riboswitch. This innovative method enables concurrent control of target gene expression at both transcription and translation initiation levels. Using luciferase and the indole-producing enzyme tryptophanase (TnaA) as reporters, we demonstrated that the hybrid system displays virtually no observable signal in the absence of inducers. We employed this system to express FtsX, a protein related to fusobacterial cytokinesis, in an ftsX mutant strain, unveiling a dose-dependent manner in FtsX production. Without inducers, cells form long filaments, while increasing FtsX levels by increasing inducers concentrations led to a gradual reduction in cell length until normal morphology was restored. Crucially, this system facilitated essential gene investigation, identifying the signal peptidase lepB gene as vital for F. nucleatum . LepB's essentiality stems from depletion, affecting outer membrane biogenesis and cell division. This novel hybrid system holds the potential for advancing research on essential genes and accurate gene regulation in F. nucleatum .
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18
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Brogan AP, Rudner DZ. Regulation of peptidoglycan hydrolases: localization, abundance, and activity. Curr Opin Microbiol 2023; 72:102279. [PMID: 36812681 PMCID: PMC10031507 DOI: 10.1016/j.mib.2023.102279] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 02/22/2023]
Abstract
Most bacteria are surrounded by a cell wall composed of peptidoglycan (PG) that specifies shape and protects the cell from osmotic rupture. Growth, division, and morphogenesis are intimately linked to the synthesis of this exoskeleton but also its hydrolysis. The enzymes that cleave the PG meshwork require careful control to prevent aberrant hydrolysis and loss of envelope integrity. Bacteria employ diverse mechanisms to control the activity, localization, and abundance of these potentially autolytic enzymes. Here, we discuss four examples of how cells integrate these control mechanisms to finely tune cell wall hydrolysis. We highlight recent advances and exciting avenues for future investigation.
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Affiliation(s)
- Anna P Brogan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
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19
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FtsEX-independent control of RipA-mediated cell separation in Corynebacteriales. Proc Natl Acad Sci U S A 2022; 119:e2214599119. [PMID: 36469781 PMCID: PMC9897464 DOI: 10.1073/pnas.2214599119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The bacterial cell wall is a multi-layered mesh, whose major component is peptidoglycan (PG), a sugar polymer cross-linked by short peptide stems. During cell division, a careful balance of PG synthesis and degradation, precisely coordinated both in time and space, is necessary to prevent uncontrolled destruction of the cell wall. In Corynebacteriales, the D,L endopeptidase RipA has emerged as a major PG hydrolase for cell separation, and RipA defaults have major implications for virulence of the human pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae. However, the precise mechanisms by which RipA mediates cell separation remain elusive. Here we report phylogenetic, biochemical, and structural analysis of the Corynebacterium glutamicum homologue of RipA, Cg1735. The crystal structures of full-length Cg1735 in two different crystal forms revealed the C-terminal NlpC/P60 catalytic domain obtruded by its N-terminal conserved coiled-coil domain, which locks the enzyme in an autoinhibited state. We show that this autoinhibition is relieved by the extracellular core domain of the transmembrane septal protein Cg1604. The crystal structure of Cg1604 revealed a (β/α) protein with an overall topology similar to that of receiver domains from response regulator proteins. The atomic model of the Cg1735-Cg1604 complex, based on bioinformatical and mutational analysis, indicates that a conserved, distal-membrane helical insertion in Cg1604 is responsible for Cg1735 activation. The reported data provide important insights into how intracellular cell division signal(s), yet to be identified, control PG hydrolysis during RipA-mediated cell separation in Corynebacteriales.
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20
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Page JE, Skiba MA, Do T, Kruse AC, Walker S. Metal cofactor stabilization by a partner protein is a widespread strategy employed for amidase activation. Proc Natl Acad Sci U S A 2022; 119:e2201141119. [PMID: 35733252 PMCID: PMC9245657 DOI: 10.1073/pnas.2201141119] [Citation(s) in RCA: 3] [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: 01/20/2022] [Accepted: 05/13/2022] [Indexed: 12/24/2022] Open
Abstract
Construction and remodeling of the bacterial peptidoglycan (PG) cell wall must be carefully coordinated with cell growth and division. Central to cell wall construction are hydrolases that cleave bonds in peptidoglycan. These enzymes also represent potential new antibiotic targets. One such hydrolase, the amidase LytH in Staphylococcus aureus, acts to remove stem peptides from PG, controlling where substrates are available for insertion of new PG strands and consequently regulating cell size. When it is absent, cells grow excessively large and have division defects. For activity, LytH requires a protein partner, ActH, that consists of an intracellular domain, a large rhomboid protease domain, and three extracellular tetratricopeptide repeats (TPRs). Here, we demonstrate that the amidase-activating function of ActH is entirely contained in its extracellular TPRs. We show that ActH binding stabilizes metals in the LytH active site and that LytH metal binding in turn is needed for stable complexation with ActH. We further present a structure of a complex of the extracellular domains of LytH and ActH. Our findings suggest that metal cofactor stabilization is a general strategy used by amidase activators and that ActH houses multiple functions within a single protein.
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Affiliation(s)
- Julia E. Page
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Meredith A. Skiba
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Truc Do
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Andrew C. Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Suzanne Walker
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
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21
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Boelter G, Bryant JA, Doherty H, Wotherspoon P, Alodaini D, Ma X, Alao MB, Moynihan PJ, Moradigaravand D, Glinkowska M, Knowles TJ, Henderson IR, Banzhaf M. The lipoprotein DolP affects cell separation in Escherichia coli, but not as an upstream regulator of NlpD. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35604759 DOI: 10.1099/mic.0.001197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacterial amidases are essential to split the shared envelope of adjunct daughter cells to allow cell separation. Their activity needs to be precisely controlled to prevent cell lysis. In Escherichia coli, amidase activity is controlled by three regulatory proteins NlpD, EnvC and ActS. However, recent studies linked the outer membrane lipoprotein DolP (formerly YraP) as a potential upstream regulator of NlpD. In this study we explored this link in further detail. To our surprise DolP did not modulate amidase activity in vitro and was unable to interact with NlpD in pull-down and MST (MicroScale Thermophoresis) assays. Next, we excluded the hypothesis that ΔdolP phenocopied ΔnlpD in a range of envelope stresses. However, morphological analysis of double deletion mutants of amidases (AmiA, AmiB AmiC) and amidase regulators with dolP revealed that ΔamiAΔdolP and ΔenvCΔdolP mutants display longer chain length compared to their parental strains indicating a role for DolP in cell division. Overall, we present evidence that DolP does not affect NlpD function in vitro, implying that DolP is not an upstream regulator of NlpD. However, DolP may impact daughter cell separation by interacting directly with AmiA or AmiC, or by a yet undiscovered mechanism.
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Affiliation(s)
- Gabriela Boelter
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Jack A Bryant
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Hannah Doherty
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Peter Wotherspoon
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Dema Alodaini
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Xuyu Ma
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Micheal B Alao
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Patrick J Moynihan
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Danesh Moradigaravand
- Centre for Computational Biology, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Monika Glinkowska
- Department of Bacterial Molecular Genetics, University of Gdansk, Gdańsk, Poland
| | - Timothy J Knowles
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Ian R Henderson
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK.,Institute for Molecular Bioscience, University of Queensland, St. Lucia, Australia
| | - Manuel Banzhaf
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
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22
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Verheul J, Lodge A, Yau HCL, Liu X, Boelter G, Liu X, Solovyova AS, Typas A, Banzhaf M, Vollmer W, den Blaauwen T. Early midcell localization of Escherichia coli PBP4 supports the function of peptidoglycan amidases. PLoS Genet 2022; 18:e1010222. [PMID: 35604931 PMCID: PMC9166362 DOI: 10.1371/journal.pgen.1010222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 06/03/2022] [Accepted: 04/27/2022] [Indexed: 11/24/2022] Open
Abstract
Insertion of new material into the Escherichia coli peptidoglycan (PG) sacculus between the cytoplasmic membrane and the outer membrane requires a well-organized balance between synthetic and hydrolytic activities to maintain cell shape and avoid lysis. Since most bacteria carry multiple enzymes carrying the same type of PG hydrolytic activity, we know little about the specific function of given enzymes. Here we show that the DD-carboxy/endopeptidase PBP4 localizes in a PBP1A/LpoA and FtsEX dependent fashion at midcell during septal PG synthesis. Midcell localization of PBP4 requires its non-catalytic domain 3 of unknown function, but not the activity of PBP4 or FtsE. Microscale thermophoresis with isolated proteins shows that PBP4 interacts with NlpI and the FtsEX-interacting protein EnvC, an activator of amidases AmiA and AmiB, which are needed to generate denuded glycan strands to recruit the initiator of septal PG synthesis, FtsN. The domain 3 of PBP4 is needed for the interaction with NlpI and EnvC, but not PBP1A or LpoA. In vivo crosslinking experiments confirm the interaction of PBP4 with PBP1A and LpoA. We propose that the interaction of PBP4 with EnvC, whilst not absolutely necessary for mid-cell recruitment of either protein, coordinates the activities of PBP4 and the amidases, which affects the formation of denuded glycan strands that attract FtsN. Consistent with this model, we found that the divisome assembly at midcell was premature in cells lacking PBP4, illustrating how the complexity of interactions affect the timing of cell division initiation. Peptidoglycan biosynthesis is a major target for antibacterials. The covalently closed peptidoglycan mesh, called sacculus, protects the bacterium from lysis due to its turgor. Sacculus growth is facilitated by the balanced activities of synthases and hydrolases, and disturbing this balance leads to cell lysis and bacterial death. Because of the large number and possible redundant functions of peptidoglycan hydrolases, it has been difficult to decipher their individual functions. In this paper we show that the DD-endopeptidase PBP4 localizes at midcell during septal peptidoglycan synthesis in Escherichia coli and is involved in the timing of the assembly and activation of the division machinery. This shows that inhibition of certain hydrolases could weaken the cells and might enhance antibiotic action.
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Affiliation(s)
- Jolanda Verheul
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Adam Lodge
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hamish C. L. Yau
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Xiaolong Liu
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Gabriela Boelter
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Xinwei Liu
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
- European Molecular Biology Laboratory, Structural & Computational Unit, Heidelberg, Germany
| | - Manuel Banzhaf
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (MB); (WV); (TdB)
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail: (MB); (WV); (TdB)
| | - Tanneke den Blaauwen
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail: (MB); (WV); (TdB)
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23
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Attaibi M, den Blaauwen T. An Updated Model of the Divisome: Regulation of the Septal Peptidoglycan Synthesis Machinery by the Divisome. Int J Mol Sci 2022; 23:3537. [PMID: 35408901 PMCID: PMC8998562 DOI: 10.3390/ijms23073537] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/06/2023] Open
Abstract
The synthesis of a peptidoglycan septum is a fundamental part of bacterial fission and is driven by a multiprotein dynamic complex called the divisome. FtsW and FtsI are essential proteins that synthesize the peptidoglycan septum and are controlled by the regulatory FtsBLQ subcomplex and the activator FtsN. However, their mode of regulation has not yet been uncovered in detail. Understanding this process in detail may enable the development of new compounds to combat the rise in antibiotic resistance. In this review, recent data on the regulation of septal peptidoglycan synthesis is summarized and discussed. Based on structural models and the collected data, multiple putative interactions within FtsWI and with regulators are uncovered. This elaborates on and supports an earlier proposed model that describes active and inactive conformations of the septal peptidoglycan synthesis complex that are stabilized by these interactions. Furthermore, a new model on the spatial organization of the newly synthesized peptidoglycan and the synthesis complex is presented. Overall, the updated model proposes a balance between several allosteric interactions that determine the state of septal peptidoglycan synthesis.
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Affiliation(s)
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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24
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Ladant D. A Bacterial Two-Hybrid System for In Vivo Assays of Protein-Protein Interactions and Drug Discovery. Methods Mol Biol 2022; 2548:145-167. [PMID: 36151497 DOI: 10.1007/978-1-0716-2581-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The bacterial adenylate cyclase-based two-hybrid (BACTH) system is a robust and simple genetic assay used to monitor protein-protein interactions in vivo. This system is based on functional complementation between two fragments from the catalytic domain of Bordetella pertussis adenylate cyclase (AC) to reconstitute a cyclic AMP (cAMP)-signaling cascade in Escherichia coli. Interactions between two chimeric proteins result in the synthesis of cAMP, which activates the transcription of various catabolite operons, leading to selectable phenotypes. One advantageous feature of this signaling cascade is that the physical association between the two interacting hybrid proteins is spatially separated from the transcriptional activation readout. Consequently, the BACTH system can detect protein-protein interactions occurring at various subcellular localizations. The system has been used to characterize interactions between soluble or membrane proteins of prokaryotic, eukaryotic, or viral origin. The BACTH assay can be used to uncover the region(s), domain(s), or amino acid residue(s) of a protein involved in an interaction with a specific partner. The BACTH system can also be adapted for the high-throughput screening of small molecules able to interfere with protein-protein interactions.
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Affiliation(s)
- Daniel Ladant
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, Paris Cedex 15, France.
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25
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Alcorlo M, Martínez-Caballero S, Molina R, Hermoso JA. Regulation of Lytic Machineries by the FtsEX Complex in the Bacterial Divisome. Subcell Biochem 2022; 99:285-315. [PMID: 36151380 DOI: 10.1007/978-3-031-00793-4_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The essential membrane complex FtsE/FtsX (FtsEX), belonging to the ABC transporter superfamily and widespread among bacteria, plays a relevant function in some crucial cell wall remodeling processes such as cell division, elongation, or sporulation. FtsEX plays a double role by recruiting proteins to the divisome apparatus and by regulating lytic activity of the cell wall hydrolases required for daughter cell separation. Interestingly, FtsEX does not act as a transporter but uses the ATPase activity of FtsE to mechanically transmit a signal from the cytosol, through the membrane, to the periplasm that activates the attached hydrolases. While the complete molecular details of such mechanism are not yet known, evidence has been recently reported that clarify essential aspects of this complex system. In this chapter we will present recent structural advances on this topic. The three-dimensional structure of FtsE, FtsX, and some of the lytic enzymes or their cognate regulators revealed an unexpected scenario in which a delicate set of intermolecular interactions, conserved among different bacterial genera, could be at the core of this regulatory mechanism providing exquisite control in both space and time of this central process to assist bacterial survival.
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Affiliation(s)
- Martín Alcorlo
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
| | - Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
- Department of Chemistry of Biomacromolecules, Universidade Nacional Autonoma de Mexico, Ciudad de México, Mexico
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain.
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26
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Briggs NS, Bruce KE, Naskar S, Winkler ME, Roper DI. The Pneumococcal Divisome: Dynamic Control of Streptococcus pneumoniae Cell Division. Front Microbiol 2021; 12:737396. [PMID: 34737730 PMCID: PMC8563077 DOI: 10.3389/fmicb.2021.737396] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Cell division in Streptococcus pneumoniae (pneumococcus) is performed and regulated by a protein complex consisting of at least 14 different protein elements; known as the divisome. Recent findings have advanced our understanding of the molecular events surrounding this process and have provided new understanding of the mechanisms that occur during the division of pneumococcus. This review will provide an overview of the key protein complexes and how they are involved in cell division. We will discuss the interaction of proteins in the divisome complex that underpin the control mechanisms for cell division and cell wall synthesis and remodelling that are required in S. pneumoniae, including the involvement of virulence factors and capsular polysaccharides.
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Affiliation(s)
- Nicholas S. Briggs
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Kevin E. Bruce
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Souvik Naskar
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Malcolm E. Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - David I. Roper
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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27
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Figueroa-Cuilan WM, Randich AM, Dunn CM, Santiago-Collazo G, Yowell A, Brown PJB. Diversification of LytM Protein Functions in Polar Elongation and Cell Division of Agrobacterium tumefaciens. Front Microbiol 2021; 12:729307. [PMID: 34489918 PMCID: PMC8416486 DOI: 10.3389/fmicb.2021.729307] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 07/26/2021] [Indexed: 12/05/2022] Open
Abstract
LytM-domain containing proteins are LAS peptidases (lysostaphin-type enzymes, D-Ala-D-Ala metallopeptidases, and sonic hedgehog) and are known to play diverse roles throughout the bacterial cell cycle through direct or indirect hydrolysis of the bacterial cell wall. A subset of the LytM factors are catalytically inactive but regulate the activity of other cell wall hydrolases and are classically described as cell separation factors NlpD and EnvC. Here, we explore the function of four LytM factors in the alphaproteobacterial plant pathogen Agrobacterium tumefaciens. An LmdC ortholog (Atu1832) and a MepM ortholog (Atu4178) are predicted to be catalytically active. While Atu1832 does not have an obvious function in cell growth or division, Atu4178 is essential for polar growth and likely functions as a space-making endopeptidase that cleaves amide bonds in the peptidoglycan cell wall during elongation. The remaining LytM factors are degenerate EnvC and NlpD orthologs. Absence of these proteins results in striking phenotypes indicative of misregulation of cell division and growth pole establishment. The deletion of an amidase, AmiC, closely phenocopies the deletion of envC suggesting that EnvC might regulate AmiC activity. The NlpD ortholog DipM is unprecedently essential for viability and depletion results in the misregulation of early stages of cell division, contrasting with the canonical view of DipM as a cell separation factor. Finally, we make the surprising observation that absence of AmiC relieves the toxicity induced by dipM overexpression. Together, these results suggest EnvC and DipM may function as regulatory hubs with multiple partners to promote proper cell division and establishment of polarity.
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Affiliation(s)
| | - Amelia M. Randich
- Department of Biology, University of Scranton, Scranton, PA, United States
| | - Caroline M. Dunn
- Division of Biological Sciences, University of Missouri, Columbia, MO, United States
| | - Gustavo Santiago-Collazo
- Division of Biological Sciences, University of Missouri, Columbia, MO, United States
- Molecular Pathogenesis and Therapeutics Graduate Program, University of Missouri, Columbia, MO, United States
| | - Andrew Yowell
- Division of Biological Sciences, University of Missouri, Columbia, MO, United States
| | - Pamela J. B. Brown
- Division of Biological Sciences, University of Missouri, Columbia, MO, United States
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28
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Abstract
Most bacteria are surrounded by a peptidoglycan cell wall that defines their shape and protects them from osmotic lysis. The expansion and division of this structure therefore plays an integral role in bacterial growth and division. Additionally, the biogenesis of the peptidoglycan layer is the target of many of our most effective antibiotics. Thus, a better understanding of how the cell wall is built will enable the development of new therapies to combat the rise of drug-resistant bacterial infections. This review covers recent advances in defining the mechanisms involved in assembling the peptidoglycan layer with an emphasis on discoveries related to the function and regulation of the cell elongation and division machineries in the model organisms Escherichia coli and Bacillus subtilis. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Patricia D A Rohs
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Current affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Thomas G Bernhardt
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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29
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Gurnani Serrano CK, Winkle M, Martorana AM, Biboy J, Morè N, Moynihan P, Banzhaf M, Vollmer W, Polissi A. ActS activates peptidoglycan amidases during outer membrane stress in Escherichia coli. Mol Microbiol 2021; 116:329-342. [PMID: 33660879 PMCID: PMC8360153 DOI: 10.1111/mmi.14712] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 12/22/2022]
Abstract
The integrity of the cell envelope of E. coli relies on the concerted activity of multi-protein machineries that synthesize the peptidoglycan (PG) and the outer membrane (OM). Our previous work found that the depletion of lipopolysaccharide (LPS) export to the OM induces an essential PG remodeling process involving LD-transpeptidases (LDTs), the glycosyltransferase function of PBP1B and the carboxypeptidase PBP6a. Consequently, cells with defective OM biogenesis lyse if they lack any of these PG enzymes. Here we report that the morphological defects, and lysis associated with a ldtF mutant with impaired LPS transport, are alleviated by the loss of the predicted OM-anchored lipoprotein ActS (formerly YgeR). We show that ActS is an inactive member of LytM-type peptidoglycan endopeptidases due to a degenerated catalytic domain. ActS is capable of activating all three main periplasmic peptidoglycan amidases, AmiA, AmiB, and AmiC, which were previously reported to be activated only by EnvC and/or NlpD. Our data also suggest that in vivo ActS preferentially activates AmiC and that its function is linked to cell envelope stress.
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Affiliation(s)
| | - Matthias Winkle
- The Centre for Bacterial Cell BiologyBiosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Alessandra M. Martorana
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanItaly
| | - Jacob Biboy
- The Centre for Bacterial Cell BiologyBiosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Niccolo Morè
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanItaly
- Present address:
Nikon Instruments Europe B.VAmsterdamNorth HollandNetherlands
| | - Patrick Moynihan
- Institute of Microbiology and InfectionSchool of Biological SciencesUniversity of BirminghamBirminghamUK
| | - Manuel Banzhaf
- Institute of Microbiology and InfectionSchool of Biological SciencesUniversity of BirminghamBirminghamUK
| | - Waldemar Vollmer
- The Centre for Bacterial Cell BiologyBiosciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Alessandra Polissi
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanItaly
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30
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Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
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Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
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31
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Bioengineering of Bordetella pertussis Adenylate Cyclase Toxin for Vaccine Development and Other Biotechnological Purposes. Toxins (Basel) 2021; 13:toxins13020083. [PMID: 33499260 PMCID: PMC7911819 DOI: 10.3390/toxins13020083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
The adenylate cyclase toxin, CyaA, is one of the key virulent factors produced by Bordetella pertussis, the causative agent of whooping cough. This toxin primarily targets innate immunity to facilitate bacterial colonization of the respiratory tract. CyaA exhibits several remarkable characteristics that have been exploited for various applications in vaccinology and other biotechnological purposes. CyaA has been engineered as a potent vaccine vehicle to deliver antigens into antigen-presenting cells, while the adenylate cyclase catalytic domain has been used to design a robust genetic assay for monitoring protein-protein interactions in bacteria. These two biotechnological applications are briefly summarized in this chapter.
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32
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Bennett MM, Cook CN, Smith BH, Lei H. Early olfactory, but not gustatory processing, is affected by the selection of heritable cognitive phenotypes in honey bee. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 207:17-26. [PMID: 33201304 DOI: 10.1007/s00359-020-01451-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/11/2020] [Accepted: 10/14/2020] [Indexed: 10/23/2022]
Abstract
Associative learning enables animals to predict rewards or punishments by their associations with predictive stimuli, while non-associative learning occurs without reinforcement. The latter includes latent inhibition (LI), whereby animals learn to ignore an inconsequential 'familiar' stimulus. Individual honey bees display heritable differences in expression of LI. We examined the behavioral and neuronal responses between honey bee genetic lines exhibiting high and low LI. We observed, as in previous studies, that high LI lines learned a familiar odor more slowly than low LI bees. By measuring gustatory responses to sucrose, we determined that perception of sucrose reward was similar between both lines, thereby not contributing to the LI phenotype. We then used extracellular electrophysiology to determine differences in neural responses of the antennal lobe (AL) to familiar and novel odors between the lines. Low LI bees responded significantly more strongly to both familiar and novel odors than the high LI bees, but the lines showed equivalent differences in response to the novel and familiar odors. This work suggests that some effects of genotype are present in early olfactory processing, and those effects could complement how LI is manifested at later stages of processing in brains of bees in the different lines.
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Affiliation(s)
- Meghan M Bennett
- Carl Hayden Bee Research Center, USDA-ARS, Tucson, AZ, 85719, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Chelsea N Cook
- Department of Biological Sciences, Marquette University, Milwaukee, WI, 53233, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Brian H Smith
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Hong Lei
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
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