1
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Whitley KD, Grimshaw J, Roberts DM, Karinou E, Stansfeld PJ, Holden S. Peptidoglycan synthesis drives a single population of septal cell wall synthases during division in Bacillus subtilis. Nat Microbiol 2024; 9:1064-1074. [PMID: 38480901 PMCID: PMC10994842 DOI: 10.1038/s41564-024-01650-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/23/2024] [Indexed: 04/06/2024]
Abstract
Bacterial cell division requires septal peptidoglycan (sPG) synthesis by the divisome complex. Treadmilling of the essential tubulin homologue FtsZ has been implicated in septal constriction, though its precise role remains unclear. Here we used live-cell single-molecule imaging of the divisome transpeptidase PBP2B to investigate sPG synthesis dynamics in Bacillus subtilis. In contrast to previous models, we observed a single population of processively moving PBP2B molecules whose motion is driven by peptidoglycan synthesis and is not associated with FtsZ treadmilling. However, despite the asynchronous motions of PBP2B and FtsZ, a partial dependence of PBP2B processivity on FtsZ treadmilling was observed. Additionally, through single-molecule counting experiments we provide evidence that the divisome synthesis complex is multimeric. Our results support a model for B. subtilis division where a multimeric synthesis complex follows a single track dependent on sPG synthesis whose activity and dynamics are asynchronous with FtsZ treadmilling.
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Affiliation(s)
- Kevin D Whitley
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
| | - James Grimshaw
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - David M Roberts
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Eleni Karinou
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Phillip J Stansfeld
- School of Life Sciences, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
| | - Séamus Holden
- School of Life Sciences, University of Warwick, Coventry, UK.
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2
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Castanheira S, García-Del Portillo F. Evidence of two differentially regulated elongasomes in Salmonella. Commun Biol 2023; 6:923. [PMID: 37689828 PMCID: PMC10492807 DOI: 10.1038/s42003-023-05308-w] [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: 06/23/2023] [Accepted: 09/01/2023] [Indexed: 09/11/2023] Open
Abstract
Cell shape is genetically inherited by all forms of life. Some unicellular microbes increase niche adaptation altering shape whereas most show invariant morphology. A universal system of peptidoglycan synthases guided by cytoskeletal scaffolds defines bacterial shape. In rod-shaped bacteria, this system consists of two supramolecular complexes, the elongasome and divisome, which insert cell wall material along major and minor axes. Microbes with invariant shape are thought to use a single morphogenetic system irrespective of the occupied niche. Here, we provide evidence for two elongasomes that generate (rod) shape in the same bacterium. This phenomenon was unveiled in Salmonella, a pathogen that switches between extra- and intracellular lifestyles. The two elongasomes can be purified independently, respond to different environmental cues, and are directed by distinct peptidoglycan synthases: the canonical PBP2 and the pathogen-specific homologue PBP2SAL. The PBP2-elongasome responds to neutral pH whereas that directed by PBP2SAL assembles in acidic conditions. Moreover, the PBP2SAL-elongasome moves at a lower speed. Besides Salmonella, other human, animal, and plant pathogens encode alternative PBPs with predicted morphogenetic functions. Therefore, contrasting the view of morphological plasticity facilitating niche adaptation, some pathogens may have acquired alternative systems to preserve their shape in the host.
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Affiliation(s)
- Sónia Castanheira
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Darwin 3, 28049, Madrid, Spain
| | - Francisco García-Del Portillo
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Darwin 3, 28049, Madrid, Spain.
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3
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Nanninga N. Molecular Cytology of 'Little Animals': Personal Recollections of Escherichia coli (and Bacillus subtilis). Life (Basel) 2023; 13:1782. [PMID: 37629639 PMCID: PMC10455606 DOI: 10.3390/life13081782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
This article relates personal recollections and starts with the origin of electron microscopy in the sixties of the previous century at the University of Amsterdam. Novel fixation and embedding techniques marked the discovery of the internal bacterial structures not visible by light microscopy. A special status became reserved for the freeze-fracture technique. By freeze-fracturing chemically fixed cells, it proved possible to examine the morphological effects of fixation. From there on, the focus switched from bacterial structure as such to their cell cycle. This invoked bacterial physiology and steady-state growth combined with electron microscopy. Electron-microscopic autoradiography with pulses of [3H] Dap revealed that segregation of replicating DNA cannot proceed according to a model of zonal growth (with envelope-attached DNA). This stimulated us to further investigate the sacculus, the peptidoglycan macromolecule. In particular, we focused on the involvement of penicillin-binding proteins such as PBP2 and PBP3, and their role in division. Adding aztreonam (an inhibitor of PBP3) blocked ongoing divisions but not the initiation of new ones. A PBP3-independent peptidoglycan synthesis (PIPS) appeared to precede a PBP3-dependent step. The possible chemical nature of PIPS is discussed.
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Affiliation(s)
- Nanne Nanninga
- Molecular Cytology, Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
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4
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Kishore V, Gaiwala Sharma SS, Raghunand TR. Septum site placement in Mycobacteria - identification and characterisation of mycobacterial homologues of Escherichia coli MinD. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001359. [PMID: 37526955 PMCID: PMC10482377 DOI: 10.1099/mic.0.001359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 06/22/2023] [Indexed: 08/02/2023]
Abstract
A major virulence trait of Mycobacterium tuberculosis (M. tb) is its ability to enter a dormant state within its human host. Since cell division is intimately linked to metabolic shut down, understanding the mechanism of septum formation and its integration with other events in the division pathway is likely to offer clues to the molecular basis of dormancy. The M. tb genome lacks obvious homologues of several conserved cell division proteins, and this study was aimed at identifying and functionally characterising mycobacterial homologues of the E. coli septum site specification protein MinD (Ec MinD). Sequence homology based analyses suggested that the genomes of both M. tb and the saprophyte Mycobacterium smegmatis (M. smegmatis) encode two putative Ec MinD homologues - Rv1708/MSMEG_3743 and Rv3660c/ MSMEG_6171. Of these, Rv1708/MSMEG_3743 were found to be the true homologues, through complementation of the E. coli ∆minDE mutant HL1, overexpression studies, and structural comparisons. Rv1708 and MSMEG_3743 fully complemented the mini-cell phenotype of HL1, and over-expression of MSMEG_3743 in M. smegmatis led to cell elongation and a drastic decrease in c.f.u. counts, indicating its essentiality in cell-division. MSMEG_3743 displayed ATPase activity, consistent with its containing a conserved Walker A motif. Interaction of Rv1708 with the chromosome associated proteins ScpA and ParB, implied a link between its septum formation role, and chromosome segregation. Comparative structural analyses showed Rv1708 to be closer in similarity to Ec MinD than Rv3660c. In summary we identify Rv1708 and MSMEG_3743 to be homologues of Ec MinD, adding a critical missing piece to the mycobacterial cell division puzzle.
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Affiliation(s)
- Vimal Kishore
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road Hyderabad - 500007, India
- Present address: National Centre for Cell Science (NCCS), NCCS Complex, University of Pune Campus, Pune University Rd, Ganeshkhind, Pune, 411007, India
| | - Sujata S. Gaiwala Sharma
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road Hyderabad - 500007, India
- Present address: Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008, India
| | - Tirumalai R. Raghunand
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road Hyderabad - 500007, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
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5
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In vitro studies of the protein-interaction network of cell-wall lytic transglycosylase RlpA of Pseudomonas aeruginosa. Commun Biol 2022; 5:1314. [PMID: 36451021 PMCID: PMC9712689 DOI: 10.1038/s42003-022-04230-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022] Open
Abstract
The protein networks of cell-wall-biosynthesis assemblies are largely unknown. A key class of enzymes in these assemblies is the lytic transglycosylases (LTs), of which eleven exist in P. aeruginosa. We have undertaken a pulldown strategy in conjunction with mass-spectrometry-based proteomics to identify the putative binding partners for the eleven LTs of P. aeruginosa. A total of 71 putative binding partners were identified for the eleven LTs. A systematic assessment of the binding partners of the rare lipoprotein A (RlpA), one of the pseudomonal LTs, was made. This 37-kDa lipoprotein is involved in bacterial daughter-cell separation by an unknown process. RlpA participates in both the multi-protein and multi-enzyme divisome and elongasome assemblies. We reveal an extensive protein-interaction network for RlpA involving at least 19 proteins. Their kinetic parameters for interaction with RlpA were assessed by microscale thermophoresis, surface-plasmon resonance, and isothermal-titration calorimetry. Notable RlpA binding partners include PBP1b, PBP4, and SltB1. Elucidation of the protein-interaction networks for each of the LTs, and specifically for RlpA, opens opportunities for the study of their roles in the complex protein assemblies intimately involved with the cell wall as a structural edifice critical for bacterial survival.
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6
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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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7
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Abstract
Single-celled organisms must adapt their physiology to persist and propagate across a wide range of environmental conditions. The growth and division of bacterial cells depend on continuous synthesis of an essential extracellular barrier: the peptidoglycan cell wall, a polysaccharide matrix that counteracts turgor pressure and confers cell shape. Unlike many other essential processes and structures within the bacterial cell, the peptidoglycan cell wall and its synthesis machinery reside at the cell surface and are thus uniquely vulnerable to the physicochemical environment and exogenous threats. In addition to the diversity of stressors endangering cell wall integrity, defects in peptidoglycan metabolism require rapid repair in order to prevent osmotic lysis, which can occur within minutes. Here, we review recent work that illuminates mechanisms that ensure robust peptidoglycan metabolism in response to persistent and acute environmental stress. Advances in our understanding of bacterial cell wall quality control promise to inform the development and use of antimicrobial agents that target the synthesis and remodeling of this essential macromolecule.IMPORTANCE Nearly all bacteria are encased in a peptidoglycan cell wall, an essential polysaccharide structure that protects the cell from osmotic rupture and reinforces cell shape. The integrity of this protective barrier must be maintained across the diversity of environmental conditions wherein bacteria replicate. However, at the cell surface, the cell wall and its synthesis machinery face unique challenges that threaten their integrity. Directly exposed to the extracellular environment, the peptidoglycan synthesis machinery encounters dynamic and extreme physicochemical conditions, which may impair enzymatic activity and critical protein-protein interactions. Biotic and abiotic stressors-including host defenses, cell wall active antibiotics, and predatory bacteria and phage-also jeopardize peptidoglycan integrity by introducing lesions, which must be rapidly repaired to prevent cell lysis. Here, we review recently discovered mechanisms that promote robust peptidoglycan synthesis during environmental and acute stress and highlight the opportunities and challenges for the development of cell wall active therapeutics.
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8
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Baranova N, Radler P, Hernández-Rocamora VM, Alfonso C, López-Pelegrín M, Rivas G, Vollmer W, Loose M. Diffusion and capture permits dynamic coupling between treadmilling FtsZ filaments and cell division proteins. Nat Microbiol 2020; 5:407-417. [PMID: 31959972 PMCID: PMC7048620 DOI: 10.1038/s41564-019-0657-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 12/06/2019] [Indexed: 11/14/2022]
Abstract
Most bacteria accomplish cell division with the help of a dynamic protein complex called the divisome, which spans the cell envelope in the plane of division. Assembly and activation of this machinery is coordinated by the tubulin-related GTPase FtsZ, which was found to form treadmilling filaments on supported bilayers in vitro1 and in live cells where they circle around the cell division site2,3. Treadmilling of FtsZ is thought to actively move proteins around the cell thereby distributing peptidoglycan synthesis and coordinating the inward growth of the septum to form the new poles of the daughter cells4. However, the molecular mechanisms underlying this function are largely unknown. Here, to study how FtsZ polymerization dynamics are coupled to downstream proteins, we reconstituted part of the bacterial cell division machinery using its purified components FtsZ, FtsA and truncated transmembrane proteins essential for cell division. We found that the membrane-bound cytosolic peptides of FtsN and FtsQ co-migrated with treadmilling FtsZ-FtsA filaments, but despite their directed collective behavior, individual peptides showed random motion and transient confinement. Our work suggests that divisome proteins follow treadmilling FtsZ filaments by a diffusion-and-capture mechanism, which can give rise to a moving zone of signaling activity at the division site.
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Affiliation(s)
- Natalia Baranova
- Institute for Science and Technology Austria, Klosterneuburg, Austria
| | - Philipp Radler
- Institute for Science and Technology Austria, Klosterneuburg, Austria
| | | | | | | | - Germán Rivas
- Centro de Investigaciones Biológicas, Madrid, Spain
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Martin Loose
- Institute for Science and Technology Austria, Klosterneuburg, Austria.
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9
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Schoenemann KM, Margolin W. Bacterial Division: FtsZ Treadmills to Build a Beautiful Wall. Curr Biol 2019; 27:R301-R303. [PMID: 28441562 DOI: 10.1016/j.cub.2017.03.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The tubulin-like FtsZ protein polymerizes into a contractile ring structure required for cytokinesis in most bacteria. Two new studies report that FtsZ polymers move around the ring by treadmilling, which guides and regulates the inward growth of the septal wall.
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Affiliation(s)
- Kara M Schoenemann
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin, MSB 1.166, Houston, TX 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin, MSB 1.166, Houston, TX 77030, USA.
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10
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Structural Insights into the FtsQ/FtsB/FtsL Complex, a Key Component of the Divisome. Sci Rep 2018; 8:18061. [PMID: 30584256 PMCID: PMC6305486 DOI: 10.1038/s41598-018-36001-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 11/13/2018] [Indexed: 11/17/2022] Open
Abstract
Bacterial cell division is a fundamental process that results in the physical separation of a mother cell into two daughter cells and involves a set of proteins known as the divisome. Among them, the FtsQ/FtsB/FtsL complex was known as a scaffold protein complex, but its overall structure and exact function is not precisely known. In this study, we have determined the crystal structure of the periplasmic domain of FtsQ in complex with the C-terminal fragment of FtsB, and showed that the C-terminal region of FtsB is a key binding region of FtsQ via mutational analysis in vitro and in vivo. We also obtained the solution structure of the periplasmic FtsQ/FtsB/FtsL complex by small angle X-ray scattering (SAXS), which reveals its structural organization. Interestingly, the SAXS and analytical gel filtration data showed that the FtsQ/FtsB/FtsL complex forms a 2:2:2 heterohexameric assembly in solution with the “Y” shape. Based on the model, the N-terminal directions of FtsQ and the FtsB/FtsL complex should be opposite, suggesting that the Y-shaped FtsQ/FtsB/FtsL complex might fit well into the curved membrane for membrane anchoring.
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11
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Condon SGF, Mahbuba DA, Armstrong CR, Diaz-Vazquez G, Craven SJ, LaPointe LM, Khadria AS, Chadda R, Crooks JA, Rangarajan N, Weibel DB, Hoskins AA, Robertson JL, Cui Q, Senes A. The FtsLB subcomplex of the bacterial divisome is a tetramer with an uninterrupted FtsL helix linking the transmembrane and periplasmic regions. J Biol Chem 2018; 293:1623-1641. [PMID: 29233891 PMCID: PMC5798294 DOI: 10.1074/jbc.ra117.000426] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 12/04/2017] [Indexed: 11/06/2022] Open
Abstract
In Escherichia coli, FtsLB plays a central role in the initiation of cell division, possibly transducing a signal that will eventually lead to the activation of peptidoglycan remodeling at the forming septum. The molecular mechanisms by which FtsLB operates in the divisome, however, are not understood. Here, we present a structural analysis of the FtsLB complex, performed with biophysical, computational, and in vivo methods, that establishes the organization of the transmembrane region and proximal coiled coil of the complex. FRET analysis in vitro is consistent with formation of a tetramer composed of two FtsL and two FtsB subunits. We predicted subunit contacts through co-evolutionary analysis and used them to compute a structural model of the complex. The transmembrane region of FtsLB is stabilized by hydrophobic packing and by a complex network of hydrogen bonds. The coiled coil domain probably terminates near the critical constriction control domain, which might correspond to a structural transition. The presence of strongly polar amino acids within the core of the tetrameric coiled coil suggests that the coil may split into two independent FtsQ-binding domains. The helix of FtsB is interrupted between the transmembrane and coiled coil regions by a flexible Gly-rich linker. Conversely, the data suggest that FtsL forms an uninterrupted helix across the two regions and that the integrity of this helix is indispensable for the function of the complex. The FtsL helix is thus a candidate for acting as a potential mechanical connection to communicate conformational changes between periplasmic, membrane, and cytoplasmic regions.
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Affiliation(s)
- Samson G F Condon
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | - Deena-Al Mahbuba
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | | | | | - Samuel J Craven
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | - Loren M LaPointe
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | - Ambalika S Khadria
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | - Rahul Chadda
- the Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - John A Crooks
- From the Department of Biochemistry
- the Integrated Program in Biochemistry
| | | | | | | | - Janice L Robertson
- the Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Qiang Cui
- the Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 and
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12
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Bisson-Filho AW, Hsu YP, Squyres GR, Kuru E, Wu F, Jukes C, Sun Y, Dekker C, Holden S, VanNieuwenhze MS, Brun YV, Garner EC. Treadmilling by FtsZ filaments drives peptidoglycan synthesis and bacterial cell division. Science 2017; 355:739-743. [PMID: 28209898 DOI: 10.1126/science.aak9973] [Citation(s) in RCA: 377] [Impact Index Per Article: 53.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/20/2017] [Indexed: 01/18/2023]
Abstract
The mechanism by which bacteria divide is not well understood. Cell division is mediated by filaments of FtsZ and FtsA (FtsAZ) that recruit septal peptidoglycan-synthesizing enzymes to the division site. To understand how these components coordinate to divide cells, we visualized their movements relative to the dynamics of cell wall synthesis during cytokinesis. We found that the division septum was built at discrete sites that moved around the division plane. FtsAZ filaments treadmilled circumferentially around the division ring and drove the motions of the peptidoglycan-synthesizing enzymes. The FtsZ treadmilling rate controlled both the rate of peptidoglycan synthesis and cell division. Thus, FtsZ treadmilling guides the progressive insertion of new cell wall by building increasingly smaller concentric rings of peptidoglycan to divide the cell.
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Affiliation(s)
- Alexandre W Bisson-Filho
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yen-Pang Hsu
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Georgia R Squyres
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Erkin Kuru
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Fabai Wu
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Netherlands
| | - Calum Jukes
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Yingjie Sun
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Netherlands.
| | - Seamus Holden
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK.
| | - Michael S VanNieuwenhze
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA. .,Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Yves V Brun
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
| | - Ethan C Garner
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA.
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13
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Stoddard PR, Williams TA, Garner E, Baum B. Evolution of polymer formation within the actin superfamily. Mol Biol Cell 2017; 28:2461-2469. [PMID: 28904122 PMCID: PMC5597319 DOI: 10.1091/mbc.e15-11-0778] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/13/2017] [Accepted: 07/18/2017] [Indexed: 01/02/2023] Open
Abstract
While many are familiar with actin as a well-conserved component of the eukaryotic cytoskeleton, it is less often appreciated that actin is a member of a large superfamily of structurally related protein families found throughout the tree of life. Actin-related proteins include chaperones, carbohydrate kinases, and other enzymes, as well as a staggeringly diverse set of proteins that use the energy from ATP hydrolysis to form dynamic, linear polymers. Despite differing widely from one another in filament structure and dynamics, these polymers play important roles in ordering cell space in bacteria, archaea, and eukaryotes. It is not known whether these polymers descended from a single ancestral polymer or arose multiple times by convergent evolution from monomeric actin-like proteins. In this work, we provide an overview of the structures, dynamics, and functions of this diverse set. Then, using a phylogenetic analysis to examine actin evolution, we show that the actin-related protein families that form polymers are more closely related to one another than they are to other nonpolymerizing members of the actin superfamily. Thus all the known actin-like polymers are likely to be the descendants of a single, ancestral, polymer-forming actin-like protein.
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Affiliation(s)
- Patrick R Stoddard
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Ethan Garner
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138
| | - Buzz Baum
- MRC-Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
- Institute of Physics of Living Systems, University College London, London WC1E 6BT, UK
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14
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Dik DA, Marous DR, Fisher JF, Mobashery S. Lytic transglycosylases: concinnity in concision of the bacterial cell wall. Crit Rev Biochem Mol Biol 2017. [PMID: 28644060 DOI: 10.1080/10409238.2017.1337705] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The lytic transglycosylases (LTs) are bacterial enzymes that catalyze the non-hydrolytic cleavage of the peptidoglycan structures of the bacterial cell wall. They are not catalysts of glycan synthesis as might be surmised from their name. Notwithstanding the seemingly mundane reaction catalyzed by the LTs, their lytic reactions serve bacteria for a series of astonishingly diverse purposes. These purposes include cell-wall synthesis, remodeling, and degradation; for the detection of cell-wall-acting antibiotics; for the expression of the mechanism of cell-wall-acting antibiotics; for the insertion of secretion systems and flagellar assemblies into the cell wall; as a virulence mechanism during infection by certain Gram-negative bacteria; and in the sporulation and germination of Gram-positive spores. Significant advances in the mechanistic understanding of each of these processes have coincided with the successive discovery of new LTs structures. In this review, we provide a systematic perspective on what is known on the structure-function correlations for the LTs, while simultaneously identifying numerous opportunities for the future study of these enigmatic enzymes.
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Affiliation(s)
- David A Dik
- a Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN , USA
| | - Daniel R Marous
- a Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN , USA
| | - Jed F Fisher
- a Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN , USA
| | - Shahriar Mobashery
- a Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , IN , USA
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15
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Nayyab S, O’Connor M, Brewster J, Gravier J, Jamieson M, Magno E, Miller RD, Phelan D, Roohani K, Williard P, Basu A, Reid CW. Diamide Inhibitors of the Bacillus subtilis N-Acetylglucosaminidase LytG That Exhibit Antibacterial Activity. ACS Infect Dis 2017; 3:421-427. [PMID: 28448118 DOI: 10.1021/acsinfecdis.7b00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
N-Acetylglucosaminidases (GlcNAcases) play an important role in the remodeling and recycling of bacterial peptidoglycan by degrading the polysaccharide backbone. Genetic deletions of autolysins can impair cell division and growth, suggesting an opportunity for using small molecule autolysin inhibitors both as tools for studying the chemical biology of autolysins and also as antibacterial agents. We report here the synthesis and evaluation of a panel of diamides that inhibit the growth of Bacillus subtilis. Two compounds, fgkc (21) and fgka (5), were found to be potent inhibitors (MIC 3.8 ± 1.0 and 21.3 ± 0.1 μM, respectively). These compounds inhibit the B. subtilis family 73 glycosyl hydrolase LytG, an exo GlcNAcase. Phenotypic analysis of fgkc (21)-treated cells demonstrates a propensity for cells to form linked chains, suggesting impaired cell growth and division.
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Affiliation(s)
- Saman Nayyab
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Mary O’Connor
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Jennifer Brewster
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - James Gravier
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Mitchell Jamieson
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Ethan Magno
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Ryan D. Miller
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Drew Phelan
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Keyana Roohani
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Paul Williard
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Amit Basu
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Christopher W. Reid
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
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16
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Egan AJF, Cleverley RM, Peters K, Lewis RJ, Vollmer W. Regulation of bacterial cell wall growth. FEBS J 2017; 284:851-867. [PMID: 27862967 DOI: 10.1111/febs.13959] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/28/2016] [Accepted: 11/09/2016] [Indexed: 12/19/2022]
Abstract
During growth and propagation, a bacterial cell enlarges and subsequently divides its peptidoglycan (PG) sacculus, a continuous mesh-like layer that encases the cell membrane to confer mechanical strength and morphological robustness. The mechanism of sacculus growth, how it is regulated and how it is coordinated with other cellular processes is poorly understood. In this article, we will discuss briefly the current knowledge of how cell wall synthesis is regulated, on multiple levels, from both sides of the cytoplasmic membrane. According to the current knowledge, cytosolic scaffolding proteins connect PG synthases with cytoskeletal elements, and protein phosphorylation regulates cell wall growth in Gram-positive species. PG-active enzymes engage in multiple protein-protein interactions within PG synthesis multienzyme complexes, and some of the interactions modulate activities. PG synthesis is also regulated by central metabolism, and by PG maturation through the action of PG hydrolytic enzymes. Only now are we beginning to appreciate how these multiple levels of regulating PG synthesis enable the cell to propagate robustly with a defined cell shape under different and variable growth conditions.
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Affiliation(s)
- Alexander J F Egan
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Robert M Cleverley
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Katharina Peters
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Richard J Lewis
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
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17
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Herrero A, Stavans J, Flores E. The multicellular nature of filamentous heterocyst-forming cyanobacteria. FEMS Microbiol Rev 2016; 40:831-854. [DOI: 10.1093/femsre/fuw029] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/10/2016] [Accepted: 07/09/2016] [Indexed: 11/13/2022] Open
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18
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Trimble MJ, Mlynárčik P, Kolář M, Hancock REW. Polymyxin: Alternative Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025288. [PMID: 27503996 DOI: 10.1101/cshperspect.a025288] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Antibiotic resistance among pathogenic bacteria is an ever-increasing issue worldwide. Unfortunately, very little has been achieved in the pharmaceutical industry to combat this problem. This has led researchers and the medical field to revisit past drugs that were deemed too toxic for clinical use. In particular, the cyclic cationic peptides polymyxin B and colistin, which are specific for Gram-negative bacteria, have been used as "last resort" antimicrobials. Before the 1980s, these drugs were known for their renal and neural toxicities; however, new clinical practices and possibly improved manufacturing have made them safer to use. Previously suggested to primarily attack the membranes of Gram-negative bacteria and to not easily select for resistant mutants, recent research exploring resistance and mechanisms of action has provided new perspectives. This review focuses primarily on the proposed alternative mechanisms of action, known resistance mechanisms, and how these support the alternative mechanisms of action.
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Affiliation(s)
- Michael J Trimble
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Patrik Mlynárčik
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University, 771 47 Olomouc, Czech Republic
| | - Milan Kolář
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University, 771 47 Olomouc, Czech Republic
| | - Robert E W Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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19
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Ouellette SP, Rueden KJ, AbdelRahman YM, Cox JV, Belland RJ. Identification and Partial Characterization of Potential FtsL and FtsQ Homologs of Chlamydia. Front Microbiol 2015; 6:1264. [PMID: 26617598 PMCID: PMC4643143 DOI: 10.3389/fmicb.2015.01264] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/30/2015] [Indexed: 12/26/2022] Open
Abstract
Chlamydia is amongst the rare bacteria that lack the critical cell division protein FtsZ. By annotation, Chlamydia also lacks several other essential cell division proteins including the FtsLBQ complex that links the early (e.g., FtsZ) and late (e.g., FtsI/Pbp3) components of the division machinery. Here, we report chlamydial FtsL and FtsQ homologs. Ct271 aligned well with Escherichia coli FtsL and shared sequence homology with it, including a predicted leucine-zipper like motif. Based on in silico modeling, we show that Ct764 has structural homology to FtsQ in spite of little sequence similarity. Importantly, ct271/ftsL and ct764/ftsQ are present within all sequenced chlamydial genomes and are expressed during the replicative phase of the chlamydial developmental cycle, two key characteristics for a chlamydial cell division gene. GFP-Ct764 localized to the division septum of dividing transformed chlamydiae, and, importantly, over-expression inhibited chlamydial development. Using a bacterial two-hybrid approach, we show that Ct764 interacted with other components of the chlamydial division apparatus. However, Ct764 was not capable of complementing an E. coli FtsQ depletion strain in spite of its ability to interact with many of the same division proteins as E. coli FtsQ, suggesting that chlamydial FtsQ may function differently. We previously proposed that Chlamydia uses MreB and other rod-shape determining proteins as an alternative system for organizing the division site and its apparatus. Chlamydial FtsL and FtsQ homologs expand the number of identified chlamydial cell division proteins and suggest that Chlamydia has likely kept the late components of the division machinery while substituting the Mre system for the early components.
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Affiliation(s)
- Scot P Ouellette
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota Vermillion, SD, USA
| | - Kelsey J Rueden
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota Vermillion, SD, USA
| | - Yasser M AbdelRahman
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center Memphis, TN, USA ; Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University Cairo, Egypt
| | - John V Cox
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center Memphis, TN, USA
| | - Robert J Belland
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center Memphis, TN, USA
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