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Mahata T, Molshanski-Mor S, Goren MG, Kohen-Manor M, Yosef I, Avram O, Salomon D, Qimron U. Inhibition of host cell division by T5 protein 008 (Hdi). Microbiol Spectr 2023; 11:e0169723. [PMID: 37888989 PMCID: PMC10714956 DOI: 10.1128/spectrum.01697-23] [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: 04/23/2023] [Accepted: 08/30/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE We have identified a novel phage-encoded inhibitor of the major cytoskeletal protein in bacterial division, FtsZ. The inhibition is shown to confer T5 bacteriophage with a growth advantage in dividing hosts. Our studies demonstrate a strategy in bacteriophages to maximize their progeny number by inhibiting escape of one of the daughter cells of an infected bacterium. They further emphasize that FtsZ is a natural target for bacterial growth inhibition.
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Affiliation(s)
- Tridib Mahata
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Molshanski-Mor
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran G. Goren
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Miriam Kohen-Manor
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ido Yosef
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Oren Avram
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Dor Salomon
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Udi Qimron
- Department of Clinical Microbiology and Immunology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
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2
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C SK, Gadewal N, Choudhary RK, Dasgupta D. Insights into the flexibility of the T3 loop and GTPase activating protein (GAP) domain of dimeric α and β tubulins from a molecular dynamics perspective. Comput Biol Chem 2019; 82:37-43. [PMID: 31255973 DOI: 10.1016/j.compbiolchem.2019.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/09/2019] [Accepted: 06/12/2019] [Indexed: 10/26/2022]
Abstract
Tubulin protein is the fundamental unit of microtubules, and comprises of α and β subunits arranged in an alternate manner forming protofilaments. These longitudinal protofilaments are made up of intra- (α-β) and inter-dimer (β-α) interactions. Literature review confirms that GTP hydrolysis results in considerable structural rearrangement within GTP binding site of β-α dimer interface after the release of γ phosphate. In addition to this, the intra-dimer interface exhibits structural rigidity which needs further investigation. In this study, we explored the reasons for the flexibility and the rigidity of the β-α dimer and the α-β dimer respectively through molecular simulation and Anisotropic Normal Mode based analysis. As per the sequence alignment report, two glycine residues (Gly96 and Gly98) were observed in the T3 loop of the β subunit which get substituted by Asp98 and Ala100 in the T3 loop of the α subunit. The higher mobility of glycine residues contributes to the flexibility of the T3 loop of inter-dimer when they come in direct contact with the GTPase Activating Protein (GAP) domain of the subunit. This was confirmed through RMSD, RMSF and Radius of Gyration based studies. Conversely, the intra-dimer exhibited a lower mobility in the absence of glycine residues. As per ANM based analysis, positive domain correlations were observed between T3 loop and GAP domain of intra- and inter- dimeric contact regions. However, these correlation motions were higher in the intra-dimer as compared to the inter-dimer interface. Thus on the basis of our findings, we hypothesize that the higher flexibility of T3 loop and the GAP domain of the inter-dimer is required for structural rearrangement and protofilament stability during hydrolysis. Furthermore, the slightly rigid nature of the T3 loop and the GAP domain of the intra-dimer assists in enhancing the monomer-monomer interaction through the higher positive domain correlation.
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Affiliation(s)
- Selvaa Kumar C
- School of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India.
| | - Nikhil Gadewal
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Kharghar, Navi Mumbai, India.
| | - Rajan Kumar Choudhary
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Kharghar, Navi Mumbai, India
| | - Debjani Dasgupta
- School of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
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3
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Abstract
FtsZ is the ancestral homolog of tubulin and assembles into the Z ring that organizes the division machinery to drive cell division in most bacteria. In contrast to tubulin that assembles into 13 stranded microtubules that undergo dynamic instability, FtsZ assembles into single-stranded filaments that treadmill to distribute the peptidoglycan synthetic machinery at the septum. Here, using longitudinal interface mutants of FtsZ, we demonstrate that the kinetic polarity of FtsZ filaments is opposite to that of microtubules. A conformational switch accompanying the assembly of FtsZ generates the kinetic polarity of FtsZ filaments, which explains the toxicity of interface mutants that function as a capper and reveals the mechanism of cooperative assembly. This approach can also be employed to determine the kinetic polarity of other filament-forming proteins.
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4
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Furusato T, Horie F, Matsubayashi HT, Amikura K, Kuruma Y, Ueda T. De Novo Synthesis of Basal Bacterial Cell Division Proteins FtsZ, FtsA, and ZipA Inside Giant Vesicles. ACS Synth Biol 2018; 7:953-961. [PMID: 29510621 DOI: 10.1021/acssynbio.7b00350] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell division is the most dynamic event in the cell cycle. Recently, efforts have been made to reconstruct it using the individual component proteins to obtain a better understanding of the process of self-reproduction of cells. However, such reconstruction studies are frequently hampered by difficulties in preparing membrane-associated proteins. Here we demonstrate a de novo synthesis approach based on a cell-free translation system. Genes for fundamental cell division proteins, FtsZ, FtsA, and ZipA, were expressed inside the lipid compartment of giant vesicles (GVs). The synthesized proteins showed polymerization, membrane localization, and eventually membrane deformation. Notably, we found that this morphological change of the vesicle is forced by only FtsZ and ZipA, which form clusters on the membrane at the vesicle interior. Our cell-free approach provides a platform for studying protein dynamics associated with lipid membrane and paves the way to create a synthetic cell that undergoes self-reproduction.
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Affiliation(s)
- Takumi Furusato
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Fumihiro Horie
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Hideaki T. Matsubayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Kazuaki Amikura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Yutetsu Kuruma
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
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5
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Chumová J, Trögelová L, Kourová H, Volc J, Sulimenko V, Halada P, Kučera O, Benada O, Kuchařová A, Klebanovych A, Dráber P, Daniel G, Binarová P. γ-Tubulin has a conserved intrinsic property of self-polymerization into double stranded filaments and fibrillar networks. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:734-748. [PMID: 29499229 DOI: 10.1016/j.bbamcr.2018.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 12/22/2022]
Abstract
γ-Tubulin is essential for microtubule nucleation and also plays less understood roles in nuclear and cell-cycle-related functions. High abundancy of γ-tubulin in acentrosomal Arabidopsis cells facilitated purification and biochemical characterization of large molecular species of γ-tubulin. TEM, fluorescence, and atomic force microscopy of purified high molecular γ-tubulin forms revealed the presence of linear filaments with a double protofilament substructure, filament bundles and aggregates. Filament formation from highly purified γ-tubulin free of γ-tubulin complex proteins (GCPs) was demonstrated for both plant and human γ-tubulin. Moreover, γ-tubulin associated with porcine brain microtubules formed oligomers. Experimental evidence on the intrinsic ability of γ-tubulin to oligomerize/polymerize was supported by conservation of α- and β-tubulin interfaces for longitudinal and lateral interactions for γ-tubulins. STED (stimulated emission depletion) microscopy of Arabidopsis cells revealed fine, short γ-tubulin fibrillar structures enriched on mitotic microtubular arrays that accumulated at polar regions of acentrosomal spindles and the outer nuclear envelope before mitosis, and were also present in nuclei. Fine fibrillar structures of γ-tubulin representing assemblies of higher order were localized in cell-cycle-dependent manner at sites of dispersed γ-tubulin location in acentrosomal plant cells as well as at sites of local γ-tubulin enrichment after drug treatment. Our findings that γ-tubulin preserves the capability of prokaryotic tubulins to self-organize into filaments assembling by lateral interaction into bundles/clusters help understanding of the relationship between structure and multiple cellular functions of this protein species and suggest that besides microtubule nucleation and organization, γ-tubulin may also have scaffolding or sequestration functions.
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Affiliation(s)
- Jana Chumová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Lucie Trögelová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Hana Kourová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Jindřich Volc
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Vadym Sulimenko
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Petr Halada
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Ondřej Kučera
- Institute of Photonics and Electronics of the Czech Academy of Sciences, Chaberská 57, 182 00 Prague 8, Czech Republic
| | - Oldřich Benada
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Anna Kuchařová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Anastasiya Klebanovych
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Pavel Dráber
- Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Geoffrey Daniel
- Department of Forest Biomaterials Technology, Swedish University of Agricultural Sciences, Box 7008, Uppsala SE-75007, Sweden
| | - Pavla Binarová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic.
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6
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Phenotypic indications of FtsZ inhibition in hok/sok-induced bacterial growth changes and stress response. Microb Pathog 2017; 114:393-401. [PMID: 29233778 DOI: 10.1016/j.micpath.2017.12.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 12/06/2017] [Accepted: 12/08/2017] [Indexed: 11/22/2022]
Abstract
The hok/sok locus has been shown to enhance the growth of bacteria in adverse growth conditions such as high temperature, low starting-culture densities and antibiotic treatment. This is in addition to their well-established plasmid-stabilization effect via post-segregational killing of plasmid-free daughter cells. It delays the onset of growth by prolonging the lag phase of bacterial culture, and increases the rate of exponential growth when growth eventually begins. This enables the cells adapt to the prevailing growth conditions and enhance their survival in stressful conditions. These effects functionally complement defective SOS response mechanism, and appear analogous to the growth effects of FtsZ in the SOS pathway. In this study, the role of FtsZ in the hok/sok-induced changes in bacterial growth and cell division was investigated. Morphologic studies of early growth-phase cultures and cells growing under temperature stress showed elongated cells typical of FtsZ inhibition/deficiency. Both ftsZ silencing and over-expression produced comparable growth effects in control cells, and altered the growth changes observed otherwise in the hok/sok+ cells. These changes were diminished in SOS-deficient strain containing mutant FtsZ. The involvement of FtsZ in the hok/sok-induced growth changes may be exploited as drug target in host bacteria, which often propagate antibiotic resistance elements.
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7
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Classic Spotlight: Boxing in the FtsZ Ring, Round One. J Bacteriol 2016; 198:2142-3. [PMID: 27471263 DOI: 10.1128/jb.00394-16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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8
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Abstract
Filamenting temperature-sensitive mutant Z (FtsZ), an essential cell division protein in bacteria, has recently emerged as an important and exploitable antibacterial target. Cytokinesis in bacteria is regulated by the assembly dynamics of this protein, which is ubiquitously present in eubacteria. The perturbation of FtsZ assembly has been found to have a deleterious effect on the cytokinetic machinery and, in turn, upon cell survival. FtsZ is highly conserved among prokaryotes, offering the possibility of broad-spectrum antibacterial agents, while its limited sequence homology with tubulin (an essential protein in eukaryotic mitosis) offers the possibility of selective toxicity. This review aims to summarize current knowledge regarding the mechanism of action of FtsZ, and to highlight existing attempts toward the development of clinically useful inhibitors.
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9
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Hurley KA, Santos TMA, Nepomuceno GM, Huynh V, Shaw JT, Weibel DB. Targeting the Bacterial Division Protein FtsZ. J Med Chem 2016; 59:6975-98. [DOI: 10.1021/acs.jmedchem.5b01098] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Katherine A. Hurley
- Department of Pharmaceutical Sciences, University of Wisconsin—Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Thiago M. A. Santos
- Department
of Biochemistry, University of Wisconsin—Madison, 440 Henry Mall, Madison, Wisconsin 53706, United States
| | - Gabriella M. Nepomuceno
- Department of Chemistry, University of California—Davis, One Shields Avenue, Davis, California 95616, United States
| | - Valerie Huynh
- Department of Chemistry, University of California—Davis, One Shields Avenue, Davis, California 95616, United States
| | - Jared T. Shaw
- Department of Chemistry, University of California—Davis, One Shields Avenue, Davis, California 95616, United States
| | - Douglas B. Weibel
- Department
of Biochemistry, University of Wisconsin—Madison, 440 Henry Mall, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Department of Biomedical Engineering, University of Wisconsin—Madison, 1550 Engineering Drive, Madison, Wisconsin 53706, United States
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10
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Nogales E. An electron microscopy journey in the study of microtubule structure and dynamics. Protein Sci 2015; 24:1912-9. [PMID: 26401895 DOI: 10.1002/pro.2808] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/18/2015] [Accepted: 09/18/2015] [Indexed: 12/30/2022]
Abstract
Structural characterization of microtubules has been the realm of three-dimensional electron microscopy and thus has evolved hand in hand with the progress of this technique, from the initial 3D reconstructions of stained tubulin assemblies, and the first atomic model of tubulin by electron crystallography of 2D sheets of protofilaments, to the ever more detailed cryoelectron microscopy structures of frozen-hydrated microtubules. Most recently, hybrid helical and single particle image processing techniques, and the latest detector technology, have lead to atomic models built directly into the density maps of microtubules in different functional states, shading new light into the critical process of microtubule dynamic instability.
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Affiliation(s)
- Eva Nogales
- Molecular and Cell Biology Department and QB3 Institute, UC Berkeley, California, 94720.,Howard Hughes Medical Institute, UC Berkeley, California, 94720.,Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720
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11
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Haeusser DP, Rowlett VW, Margolin W. A mutation in Escherichia coli ftsZ bypasses the requirement for the essential division gene zipA and confers resistance to FtsZ assembly inhibitors by stabilizing protofilament bundling. Mol Microbiol 2015; 97:988-1005. [PMID: 26046682 DOI: 10.1111/mmi.13081] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2015] [Indexed: 11/28/2022]
Abstract
The earliest step in Escherichia coli cell division consists of the assembly of FtsZ protein into a proto-ring structure, tethered to the cytoplasmic membrane by FtsA and ZipA. The proto-ring then recruits additional cell division proteins to form the divisome. Previously we described an ftsZ allele, ftsZL169R , which maps to the side of the FtsZ subunit and confers resistance to FtsZ assembly inhibitory factors including Kil of bacteriophage λ. Here we further characterize this allele and its mechanism of resistance. We found that FtsZL169R permits the bypass of the normally essential ZipA, a property previously observed for FtsA gain-of-function mutants such as FtsA* or increased levels of the FtsA-interacting protein FtsN. Similar to FtsA*, FtsZL169R also can partially suppress thermosensitive mutants of ftsQ or ftsK, which encode additional divisome proteins, and confers strong resistance to excess levels of FtsA, which normally inhibit FtsZ ring function. Additional genetic and biochemical assays provide further evidence that FtsZL169R enhances FtsZ protofilament bundling, thereby conferring resistance to assembly inhibitors and bypassing the normal requirement for ZipA. This work highlights the importance of FtsZ protofilament bundling during cell division and its likely role in regulating additional divisome activities.
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Affiliation(s)
- Daniel P Haeusser
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX, 77030, USA
| | - Veronica W Rowlett
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX, 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX, 77030, USA
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12
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Jiang XR, Wang H, Shen R, Chen GQ. Engineering the bacterial shapes for enhanced inclusion bodies accumulation. Metab Eng 2015; 29:227-237. [DOI: 10.1016/j.ymben.2015.03.017] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 02/17/2015] [Accepted: 03/31/2015] [Indexed: 11/28/2022]
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13
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The role of the hok/sok locus in bacterial response to stressful growth conditions. Microb Pathog 2015; 79:70-9. [PMID: 25625568 DOI: 10.1016/j.micpath.2015.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/26/2014] [Accepted: 01/23/2015] [Indexed: 11/23/2022]
Abstract
The hok/sok locus is renowned for its plasmid stabilization effect via post-segregational killing of plasmid-free daughter cells. However, the function(s) of the chromosome-encoded loci, which are more abundant in pathogenic strains of a broad range of enteric bacteria, are yet to be understood. Also, the frequent occurrence of this toxin/antitoxin addiction system in multi-drug resistance plasmids suggests additional roles. In this study, the effects of the hok/sok locus on the growth of bacteria in stressful growth-limiting conditions such as high temperature and antibiotic burden were investigated using hok/sok plasmids. The results showed that the hok/sok locus prolonged the lag phase of host cell cultures, thereby enabling the cells to adapt, respond to the stress and eventually thrive in these growth-limiting conditions by increasing the growth rate at exponential phase. The hok/sok locus also enhanced the survival and growth of cells in low cell density cultures irrespective of unfavourable growth conditions, and may complement existing or defective SOS mechanism. In addition to the plasmid stabilization function, these effects would enhance the ability of pathogenic bacteria to establish infections and propagate the antibiotic resistance elements carried on these plasmids, thereby contributing to the virulence of such bacteria.
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14
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Virtual screening of potential inhibitor against FtsZ protein from Staphylococcus aureus. Interdiscip Sci 2014; 6:331-9. [DOI: 10.1007/s12539-012-0229-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 07/01/2014] [Accepted: 08/22/2014] [Indexed: 10/24/2022]
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15
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Vijayalakshmi P, Nisha J, Rajalakshmi M. Virtual screening of potential inhibitor against FtsZ protein from Staphylococcus aureus. Interdiscip Sci 2014:331-339. [PMID: 25373631 DOI: 10.1007/s12539-012-0072-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 07/01/2014] [Accepted: 08/22/2014] [Indexed: 10/24/2022]
Abstract
The gram-positive bacterium Staphylococcus aureus, responsible for a wide variety of diseases in human involve all organ systems ranging from localized skin infections to life-threatening systemic infections. FtsZ, the key protein of bacterial cell division was selected as a potent anti bacterial target. In order to identify the new compounds structure based screening process was carried out. An enrichment study was performed to select a suitable scoring function and to retrieve potential candidates against FtsZ from a large chemical database. The docking score and docking energy values were compared and their atomic interaction was also evaluated. Furthermore molecular dynamics simulation were also been performed to check the stability and the amino acids interacted towards the FtsZ. Finally we selected C ID 16284, 25916, 15894, 13403 as better lead compounds. From these results, we conclude that our insilico results will provide a framework for the detailed in vitro and in vivo studies about the FtsZ protein activity in drug development process.
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Affiliation(s)
- Periyasamy Vijayalakshmi
- Bioinformatics centre (BIF), PG& Research Department of Biotechnology & Bioinformatics, Holy Cross College (Autonomous), Tiruchirapalli, 620002, Tamil Nadu, India
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16
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Tan D, Wu Q, Chen JC, Chen GQ. Engineering Halomonas TD01 for the low-cost production of polyhydroxyalkanoates. Metab Eng 2014; 26:34-47. [PMID: 25217798 DOI: 10.1016/j.ymben.2014.09.001] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/29/2014] [Accepted: 09/02/2014] [Indexed: 12/14/2022]
Abstract
The halophile Halomonas TD01 and its derivatives have been successfully developed as a low-cost platform for the unsterile and continuous production of chemicals. Therefore, to increase the genetic engineering stability of this platform, the DNA restriction/methylation system of Halomonas TD01 was partially inhibited. In addition, a stable and conjugative plasmid pSEVA341 with a high-copy number was constructed to contain a LacI(q)-Ptrc system for the inducible expression of multiple pathway genes. The Halomonas TD01 platform, was further engineered with its 2-methylcitrate synthase and three PHA depolymerases deleted within the chromosome, resulting in the production of the Halomonas TD08 strain. The overexpression of the threonine synthesis pathway and threonine dehydrogenase made the recombinant Halomonas TD08 able to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV consisting of 4-6 mol% 3-hydroxyvalerate or 3 HV, from various carbohydrates as the sole carbon source. The overexpression of the cell division inhibitor MinCD during the cell growth stationary phase in Halomonas TD08 elongated its shape to become at least 1.4-fold longer than its original size, resulting in enhanced PHB accumulation from 69 wt% to 82 wt% in the elongated cells, further promoting gravity-induced cell precipitations that simplify the downstream processing of the biomass. The resulted Halomonas strains contributed to further reducing the PHA production cost.
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Affiliation(s)
- Dan Tan
- MOE Key Lab of Bioinformatics, National Engineering Laboratory for Anti-tumor Protein Therapeutics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China; Institute of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Qiong Wu
- MOE Key Lab of Bioinformatics, National Engineering Laboratory for Anti-tumor Protein Therapeutics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jin-Chun Chen
- MOE Key Lab of Bioinformatics, National Engineering Laboratory for Anti-tumor Protein Therapeutics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guo-Qiang Chen
- MOE Key Lab of Bioinformatics, National Engineering Laboratory for Anti-tumor Protein Therapeutics, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
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17
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MinCDE exploits the dynamic nature of FtsZ filaments for its spatial regulation. Proc Natl Acad Sci U S A 2014; 111:E1192-200. [PMID: 24707052 DOI: 10.1073/pnas.1317764111] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In Escherichia coli, a contractile ring (Z-ring) is formed at midcell before cytokinesis. This ring consists primarily of FtsZ, a tubulin-like GTPase, that assembles into protofilaments similar to those in microtubules but different in their suprastructures. The Min proteins MinC, MinD, and MinE are determinants of Z-ring positioning in E. coli. MinD and MinE oscillate from pole to pole, and genetic and biochemical evidence concludes that MinC positions the Z-ring by coupling its assembly to the oscillations by direct inhibitory interaction. The mechanism of inhibition of FtsZ polymerization and, thus, positioning by MinC, however, is not understood completely. Our in vitro reconstitution experiments suggest that the Z-ring consists of dynamic protofilament bundles in which monomers constantly are exchanged throughout, stochastically creating protofilament ends along the length of the filament. From the coreconstitution of FtsZ with MinCDE, we propose that MinC acts on the filaments in two ways: by increasing the detachment rate of FtsZ-GDP within the filaments and by reducing the attachment rate of FtsZ monomers to filaments by occupying binding sites on the FtsZ filament lattice. Furthermore, our data show that the MinCDE system indeed is sufficient to cause spatial regulation of FtsZ, required for Z-ring positioning.
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18
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Gene product 0.4 increases bacteriophage T7 competitiveness by inhibiting host cell division. Proc Natl Acad Sci U S A 2013; 110:19549-54. [PMID: 24218612 DOI: 10.1073/pnas.1314096110] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacteriophages take over host resources primarily via the activity of proteins expressed early in infection. One of these proteins, produced by the Escherichia coli phage T7, is gene product (Gp) 0.4. Here, we show that Gp0.4 is a direct inhibitor of the E. coli filamenting temperature-sensitive mutant Z division protein. A chemically synthesized Gp0.4 binds to purified filamenting temperature-sensitive mutant Z protein and directly inhibits its assembly in vitro. Consequently, expression of Gp0.4 in vivo is lethal to E. coli and results in bacteria that are morphologically elongated. We further show that this inhibition of cell division by Gp0.4 enhances the bacteriophage's competitive ability. This division inhibition is thus a fascinating example of a strategy in bacteriophages to maximize utilization of their hosts' cell resources.
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Blasios V, Bisson-Filho AW, Castellen P, Nogueira MLC, Bettini J, Portugal RV, Zeri ACM, Gueiros-Filho FJ. Genetic and biochemical characterization of the MinC-FtsZ interaction in Bacillus subtilis. PLoS One 2013; 8:e60690. [PMID: 23577149 PMCID: PMC3618327 DOI: 10.1371/journal.pone.0060690] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/01/2013] [Indexed: 11/22/2022] Open
Abstract
Cell division in bacteria is regulated by proteins that interact with FtsZ and modulate its ability to polymerize into the Z ring structure. The best studied of these regulators is MinC, an inhibitor of FtsZ polymerization that plays a crucial role in the spatial control of Z ring formation. Recent work established that E. coli MinC interacts with two regions of FtsZ, the bottom face of the H10 helix and the extreme C-terminal peptide (CTP). Here we determined the binding site for MinC on Bacillus subtilis FtsZ. Selection of a library of FtsZ mutants for survival in the presence of Min overexpression resulted in the isolation of 13 Min-resistant mutants. Most of the substitutions that gave rise to Min resistance clustered around the H9 and H10 helices in the C-terminal domain of FtsZ. In addition, a mutation in the CTP of B. subtilis FtsZ also produced MinC resistance. Biochemical characterization of some of the mutant proteins showed that they exhibited normal polymerization properties but reduced interaction with MinC, as expected for binding site mutations. Thus, our study shows that the overall architecture of the MinC-FtsZ interaction is conserved in E. coli and B. subtilis. Nevertheless, there was a clear difference in the mutations that conferred Min resistance, with those in B. subtilis FtsZ pointing to the side of the molecule rather than to its polymerization interface. This observation suggests that the mechanism of Z ring inhibition by MinC differs in both species.
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Affiliation(s)
- Valdir Blasios
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | | | - Patricia Castellen
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Maria Luiza C. Nogueira
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Jefferson Bettini
- Nanotechnology National Laboratory (LNNano), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Rodrigo V. Portugal
- Nanotechnology National Laboratory (LNNano), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Ana Carolina M. Zeri
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
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20
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Grafmüller A, Noya EG, Voth GA. Nucleotide-dependent lateral and longitudinal interactions in microtubules. J Mol Biol 2013; 425:2232-46. [PMID: 23541590 DOI: 10.1016/j.jmb.2013.03.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 03/11/2013] [Accepted: 03/16/2013] [Indexed: 01/31/2023]
Abstract
Microtubule (MT) stability is related to the hydrolysis of the guanosine triphosphate nucleotide (NT) bound to β-tubulin. However, the molecular mechanism by which the NT state influences the stability of the contacts in the MT lattice remains elusive. Here, we present large-scale atomistic simulations of different tubulin aggregates, including individual dimers, short protofilaments, a small lattice patch, and a piece of the MT lattice with two infinite protofilaments in both NT states. Together with a coarse-grained (CG) analysis of the fluctuations, these simulations highlight several regions of the protein where local changes are induced by the NT state or by the lateral and longitudinal contacts in the aggregates. Additionally, the CG analysis provides an indication of how the structural changes affect the bonds between the proteins. The results suggest a consistent picture of a possible molecular mechanism by which the NT state induces changes in the H1-S2 loop and more stable longitudinal bonds, both of which locate the H1-S2 and M-loop in more favorable positions to form lateral contacts.
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Affiliation(s)
- Andrea Grafmüller
- Theory and Biosystems, Max Planck Institute for Colloids and Interfaces, 14424 Potsdam, Germany.
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21
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Ray S, Kumar A, Panda D. GTP regulates the interaction between MciZ and FtsZ: a possible role of MciZ in bacterial cell division. Biochemistry 2012; 52:392-401. [PMID: 23237472 DOI: 10.1021/bi301237m] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
MciZ, a peptide with 40 amino acid residues, has been shown to be expressed during bacterial sporulation, to inhibit Z-ring formation in bacteria, and to inhibit the assembly of FtsZ in vitro. Here, MciZ was found to bind to FtsZ in vitro with a dissociation constant of 0.3 ± 0.1 μM. Guanosine nucleotides inhibited the binding of MciZ to FtsZ; however, GTP inhibited the binding of MciZ to FtsZ more strongly than GDP. In addition, MciZ inhibited the binding of 2',3'-O-(2,4,6-trinitrocyclohexadienylidene)-GTP, a fluorescent analogue of GTP, to FtsZ. The results indicated that MciZ shares its binding site on FtsZ with GTP. Furthermore, M19I, an N-terminal 19-residue peptide (MKVHRMPKGVVLVGKAWEI) of MciZ, inhibited the assembly and GTPase activity of FtsZ in vitro. The results suggested that GTP plays an important role in the regulation of the interaction between FtsZ and MciZ and that M19I may be used as a lead peptide to design peptide inhibitors of FtsZ assembly.
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Affiliation(s)
- Shashikant Ray
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India
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22
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Singh P, Jindal B, Surolia A, Panda D. A rhodanine derivative CCR-11 inhibits bacterial proliferation by inhibiting the assembly and GTPase activity of FtsZ. Biochemistry 2012; 51:5434-42. [PMID: 22703373 DOI: 10.1021/bi201813u] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A perturbation of FtsZ assembly dynamics has been shown to inhibit bacterial cytokinesis. In this study, the antibacterial activity of 151 rhodanine compounds was assayed using Bacillus subtilis cells. Of 151 compounds, eight strongly inhibited bacterial proliferation at 2 μM. Subsequently, we used the elongation of B. subtilis cells as a secondary screen to identify potential FtsZ-targeted antibacterial agents. We found that three compounds significantly increased bacterial cell length. One of the three compounds, namely, CCR-11 [(E)-2-thioxo-5-({[3-(trifluoromethyl)phenyl]furan-2-yl}methylene)thiazolidin-4-one], inhibited the assembly and GTPase activity of FtsZ in vitro. CCR-11 bound to FtsZ with a dissociation constant of 1.5 ± 0.3 μM. A docking analysis indicated that CCR-11 may bind to FtsZ in a cavity adjacent to the T7 loop and that short halogen-oxygen, H-bonding, and hydrophobic interactions might be important for the binding of CCR-11 with FtsZ. CCR-11 inhibited the proliferation of B. subtilis cells with a half-maximal inhibitory concentration (IC(50)) of 1.2 ± 0.2 μM and a minimal inhibitory concentration of 3 μM. It also potently inhibited proliferation of Mycobacterium smegmatis cells. Further, CCR-11 perturbed Z-ring formation in B. subtilis cells; however, it neither visibly affected nucleoid segregation nor altered the membrane integrity of the cells. CCR-11 inhibited HeLa cell proliferation with an IC(50) value of 18.1 ± 0.2 μM (∼15 × IC(50) of B. subtilis cell proliferation). The results suggested that CCR-11 inhibits bacterial cytokinesis by inhibiting FtsZ assembly, and it can be used as a lead molecule to develop FtsZ-targeted antibacterial agents.
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Affiliation(s)
- Parminder Singh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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23
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Abstract
Bacterial cells utilize three-dimensional (3D) protein assemblies to perform important cellular functions such as growth, division, chemoreception, and motility. These assemblies are composed of mechanoproteins that can mechanically deform and exert force. Sometimes, small-nucleotide hydrolysis is coupled to mechanical deformations. In this review, we describe the general principle for an understanding of the coupling of mechanics with chemistry in mechanochemical systems. We apply this principle to understand bacterial cell shape and morphogenesis and how mechanical forces can influence peptidoglycan cell wall growth. We review a model that can potentially reconcile the growth dynamics of the cell wall with the role of cytoskeletal proteins such as MreB and crescentin. We also review the application of mechanochemical principles to understand the assembly and constriction of the FtsZ ring. A number of potential mechanisms are proposed, and important questions are discussed.
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24
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Buske PJ, Levin PA. Extreme C terminus of bacterial cytoskeletal protein FtsZ plays fundamental role in assembly independent of modulatory proteins. J Biol Chem 2012; 287:10945-57. [PMID: 22298780 DOI: 10.1074/jbc.m111.330324] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Bacterial cell division typically requires assembly of the cytoskeletal protein FtsZ into a ring (Z-ring) at the nascent division site that serves as a foundation for assembly of the division apparatus. High resolution imaging suggests that the Z-ring consists of short, single-stranded polymers held together by lateral interactions. Several proteins implicated in stabilizing the Z-ring enhance lateral interactions between FtsZ polymers in vitro. Here we report that residues at the C terminus of Bacillus subtilis FtsZ (C-terminal variable region (CTV)) are both necessary and sufficient for stimulating lateral interactions in vitro in the absence of modulatory proteins. Swapping the 6-residue CTV from B. subtilis FtsZ with the 4-residue CTV from Escherichia coli FtsZ completely abolished lateral interactions between chimeric B. subtilis FtsZ polymers. The E. coli FtsZ chimera readily formed higher order structures normally seen only in the presence of molecular crowding agents. CTV-mediated lateral interactions are important for the integrity of the Z-ring because B. subtilis cells expressing the B. subtilis FtsZ chimera had a low frequency of FtsZ ring formation and a high degree of filamentation relative to wild-type cells. Site-directed mutagenesis of the B. subtilis CTV suggests that electrostatic forces are an important determinant of lateral interaction potential.
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Affiliation(s)
- Paul J Buske
- Department of Biology, Washington University, Saint Louis, Missouri 63130, USA
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25
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Smith AG, Johnson CB, Vitha S, Holzenburg A. Oligomerization of plant FtsZ1 and FtsZ2 plastid division proteins. Arch Biochem Biophys 2011; 513:94-101. [PMID: 21781955 DOI: 10.1016/j.abb.2011.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/22/2011] [Accepted: 07/01/2011] [Indexed: 11/26/2022]
Abstract
FtsZ was identified in bacteria as the first protein to localize mid-cell prior to division and homologs have been found in many plant species. Bacterial studies demonstrated that FtsZ forms a ring structure that is dynamically exchanged with a soluble pool of FtsZ. Our previous work established that Arabidopsis FtsZ1 and FtsZ2-1 are capable of in vitro self-assembly into two distinct filament types, termed type-I and type-II and noted the presence of filament precursor molecules which prompted this investigation. Using a combination of electron microscopy, gel chromatography and native PAGE revealed that (i) prior to FtsZ assembly initiation the pool consists solely of dimers and (ii) during assembly of the Arabidopsis FtsZ type-II filaments the most common intermediate between the dimer and filament state is a tetramer. Three-dimensional reconstructions of the observed dimer and tetramer suggest these oligomeric forms may represent consecutive steps in type-II filament assembly and a mechanism is proposed, which is expanded to include FtsZ assembly into type-I filaments. Finally, the results permit a discussion of the oligomeric nature of the soluble pool in plants.
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Affiliation(s)
- Aaron G Smith
- Microscopy and Imaging Center, Texas A&M University, College Station, TX 77843-2257, USA
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26
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FtsZ in bacterial cytokinesis: cytoskeleton and force generator all in one. Microbiol Mol Biol Rev 2011; 74:504-28. [PMID: 21119015 DOI: 10.1128/mmbr.00021-10] [Citation(s) in RCA: 460] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
FtsZ, a bacterial homolog of tubulin, is well established as forming the cytoskeletal framework for the cytokinetic ring. Recent work has shown that purified FtsZ, in the absence of any other division proteins, can assemble Z rings when incorporated inside tubular liposomes. Moreover, these artificial Z rings can generate a constriction force, demonstrating that FtsZ is its own force generator. Here we review light microscope observations of how Z rings assemble in bacteria. Assembly begins with long-pitch helices that condense into the Z ring. Once formed, the Z ring can transition to short-pitch helices that are suggestive of its structure. FtsZ assembles in vitro into short protofilaments that are ∼30 subunits long. We present models for how these protofilaments might be further assembled into the Z ring. We discuss recent experiments on assembly dynamics of FtsZ in vitro, with particular attention to how two regulatory proteins, SulA and MinC, inhibit assembly. Recent efforts to develop antibacterial drugs that target FtsZ are reviewed. Finally, we discuss evidence of how FtsZ generates a constriction force: by protofilament bending into a curved conformation.
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27
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Abstract
Bacteria, like eukaryotes, employ cytoskeletal elements to perform many functions, including cell morphogenesis, cell division, DNA partitioning, and cell motility. They not only possess counterparts of eukaryotic actin, tubulin, and intermediate filament proteins, but they also have cytoskeletal elements of their own. Unlike the rigid sequence and structural conservation often observed for eukaryotic cytoskeletal proteins, the bacterial counterparts can display considerable diversity in sequence and function across species. Their wide range of function highlights the flexibility of core cytoskeletal protein motifs, such that one type of cytoskeletal element can perform various functions, and one function can be performed by different types of cytoskeletal elements.
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Affiliation(s)
- Matthew T Cabeen
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA
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28
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Rendine S, Pieraccini S, Sironi M. Vinblastine perturbation of tubulin protofilament structure: a computational insight. Phys Chem Chem Phys 2010; 12:15530-6. [PMID: 20978652 DOI: 10.1039/c0cp00594k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Tubulin is a heterodimeric protein whose self assembly leads to the formation of protofilaments and of more complex structures called microtubules, key components of the cytoskeleton which have a fundamental role in the cell division process. Due to its biological function, tubulin is the target of many antitumoral molecules that exert their action on proliferating tumoral cells. Among these drugs, vinblastine has been widely used in therapy for a long time, albeit its mechanism of interaction with tubulin has remained elusive until recently. Vinblastine acts as a microtubule destabilizing agent and induces the formation of curved or ring-shaped tubulin polymers instead of linear protofilaments in vitro. In this paper we compare, using molecular dynamics simulations and free energy calculations, the network of interactions that allow the assembly of model linear protofilaments with those present in curved tubulin polymers complexed with vinblastine. It is shown that vinblastine, wedging between tubulin heterodimers, actually mediates part of the interactions between them and acts by crosslinking the two proteins, leading to the observed curved polymers rather than to their disassembly.
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Affiliation(s)
- Stefano Rendine
- Dipartimento di Chimica Fisica ed Elettrochimica, Università degli Studi di Milano, Via Golgi 19, 20133, Milano, Italy
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29
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Jaiswal R, Patel RY, Asthana J, Jindal B, Balaji PV, Panda D. E93R substitution of Escherichia coli FtsZ induces bundling of protofilaments, reduces GTPase activity, and impairs bacterial cytokinesis. J Biol Chem 2010; 285:31796-805. [PMID: 20667825 DOI: 10.1074/jbc.m110.138719] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, we found that divalent calcium has no detectable effect on the assembly of Mycobacterium tuberculosis FtsZ (MtbFtsZ), whereas it strongly promoted the assembly of Escherichia coli FtsZ (EcFtsZ). While looking for potential calcium binding residues in EcFtsZ, we found a mutation (E93R) that strongly promoted the assembly of EcFtsZ. The mutation increased the stability and bundling of the FtsZ protofilaments and produced a dominating effect on the assembly of the wild type FtsZ (WT-FtsZ). Although E93R-FtsZ was found to bind to GTP similarly to the WT-FtsZ, it displayed lower GTPase activity than the WT-FtsZ. E93R-FtsZ complemented for its wild type counterpart as observed by a complementation test using JKD7-1/pKD3 cells. However, the bacterial cells became elongated upon overexpression of the mutant allele. We modeled the structure of E93R-FtsZ using the structures of MtbFtsZ/Methanococcus jannaschi FtsZ (MjFtsZ) dimers as templates. The MtbFtsZ-based structure suggests that the Arg(93)-Glu(138) salt bridge provides the additional stability, whereas the effect of mutation appears to be indirect (allosteric) if the EcFtsZ dimer is similar to that of MjFtsZ. The data presented in this study suggest that an increase in the stability of the FtsZ protofilaments is detrimental for the bacterial cytokinesis.
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Affiliation(s)
- Richa Jaiswal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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30
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Martín-Galiano AJ, Buey RM, Cabezas M, Andreu JM. Mapping flexibility and the assembly switch of cell division protein FtsZ by computational and mutational approaches. J Biol Chem 2010; 285:22554-65. [PMID: 20472561 DOI: 10.1074/jbc.m110.117127] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The molecular switch for nucleotide-regulated assembly and disassembly of the main prokaryotic cell division protein FtsZ is unknown despite the numerous crystal structures that are available. We have characterized the functional motions in FtsZ with a computational consensus of essential dynamics, structural comparisons, sequence conservation, and networks of co-evolving residues. Employing this information, we have constructed 17 mutants, which alter the FtsZ functional cycle at different stages, to modify FtsZ flexibility. The mutant phenotypes ranged from benign to total inactivation and included increased GTPase, reduced assembly, and stabilized assembly. Six mutations clustering at the long cleft between the C-terminal beta-sheet and core helix H7 deviated FtsZ assembly into curved filaments with inhibited GTPase, which still polymerize cooperatively. These mutations may perturb the predicted closure of the C-terminal domain onto H7 required for switching between curved and straight association modes and for GTPase activation. By mapping the FtsZ assembly switch, this work also gives insight into FtsZ druggability because the curved mutations delineate the putative binding site of the promising antibacterial FtsZ inhibitor PC190723.
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Affiliation(s)
- Antonio J Martín-Galiano
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
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31
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Radhakrishnan SK, Pritchard S, Viollier PH. Coupling prokaryotic cell fate and division control with a bifunctional and oscillating oxidoreductase homolog. Dev Cell 2010; 18:90-101. [PMID: 20152180 DOI: 10.1016/j.devcel.2009.10.024] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 08/31/2009] [Accepted: 10/27/2009] [Indexed: 10/19/2022]
Abstract
NAD(H)-binding proteins play important roles in cell-cycle and developmental signaling in eukaryotes. We identified a bifunctional NAD(H)-binding regulator (KidO) that integrates cell-fate signaling with cytokinesis in the bacterium Caulobacter crescentus. KidO stimulates the DivJ kinase and directly acts on the cytokinetic tubulin, FtsZ, to tune cytokinesis with the cell cycle. At the G1-->S transition, DivJ concomitantly signals the ClpXP-dependent degradation of KidO and CtrA, a cell-cycle transcriptional regulator/DNA replication inhibitor. This proteolytic event directs KidO and CtrA into oscillatory cell-cycle abundance patterns that coordinately license replication and cytokinesis. KidO resembles NAD(P)H-dependent oxidoreductases, and conserved residues in the KidO NAD(H)-binding pocket are critical for regulation of FtsZ, but not for DivJ. Since NADPH-dependent regulation by a KidO-like oxidoreductase also occurs in humans, organisms from two domains of life exploit the enzymatic fold of an ancestral oxidoreductase potentially to coordinate cellular or developmental activities with the availability of the metabolic currency, NAD(P)H.
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Affiliation(s)
- Sunish Kumar Radhakrishnan
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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32
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Shen B, Lutkenhaus J. Examination of the interaction between FtsZ and MinCN in E. coli suggests how MinC disrupts Z rings. Mol Microbiol 2010; 75:1285-98. [PMID: 20132438 DOI: 10.1111/j.1365-2958.2010.07055.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In Escherichia coli the Min system prevents Z ring assembly at cell poles by topologically regulating the division inhibitor MinC. The MinC protein has two domains of equal size and both domains can target FtsZ and block cell division in the proper context. Recently, we have shown that, along with MinD, the C-terminal domain of MinC (MinC(C)) competes with FtsA, and to a lesser extent with ZipA, for interaction with the C-terminal tail of FtsZ to block division. Here we explored the interaction between the N-terminal domain of MinC (MinC(N)) and FtsZ. A search for mutations in ftsZ that confer resistance to MinC(N) identified an alpha-helix at the interface of FtsZ subunits as being critical for the activity of MinC(N). Focusing on one such mutant FtsZ-N280D, we showed that it greatly reduced the FtsZ-MinC interaction and was resistant to MinC(N) both in vivo and in vitro. With these results, an updated model for the action of MinC on FtsZ is proposed: MinC interacts with FtsZ to disrupt two interactions, FtsZ-FtsA/ZipA and FtsZ-FtsZ, both of which are essential for Z ring formation.
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Affiliation(s)
- Bang Shen
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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van Niftrik L, Geerts WJC, van Donselaar EG, Humbel BM, Webb RI, Harhangi HR, Camp HJMOD, Fuerst JA, Verkleij AJ, Jetten MSM, Strous M. Cell division ring, a new cell division protein and vertical inheritance of a bacterial organelle in anammox planctomycetes. Mol Microbiol 2009; 73:1009-19. [DOI: 10.1111/j.1365-2958.2009.06841.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Abstract
Bacterial cell division is orchestrated by a tubulin homologue, FtsZ, which polymerizes to form a ring-like structure that is both a scaffold for the assembly of the bacterial cytokinetic machinery and, at least in part, a source of the energy for constriction. FtsZ assembly is tightly regulated, and a diverse repertoire of accessory proteins contributes to the formation of a functional division machine that is responsive to cell cycle status and environmental stress. In this Review, we describe the interaction of these proteins with FtsZ and discuss recent advances in our understanding of Z ring assembly.
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35
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Shen B, Lutkenhaus J. The conserved C-terminal tail of FtsZ is required for the septal localization and division inhibitory activity of MinC(C)/MinD. Mol Microbiol 2009; 72:410-24. [PMID: 19415799 DOI: 10.1111/j.1365-2958.2009.06651.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Escherichia coli Min system contributes to spatial regulation of cytokinesis by preventing assembly of the Z ring away from midcell. MinC is a cell division inhibitor whose activity is spatially regulated by MinD and MinE. MinC has two functional domains of similar size, both of which have division inhibitory activity in the proper context. However, the molecular mechanism of the inhibitory action of either domain is not very clear. Here, we report that the septal localization and division inhibitory activity of MinC(C)/MinD requires the conserved C-terminal tail of FtsZ. This tail also mediates interaction with two essential division proteins, ZipA and FtsA, to link FtsZ polymers to the membrane. Overproduction of MinC(C)/MinD displaces FtsA from the Z ring and eventually disrupts the Z ring, probably because it also displaces ZipA. These results support a model for the division inhibitory action of MinC/MinD. MinC/MinD binds to ZipA and FtsA decorated FtsZ polymers located at the membrane through the MinC(C)/MinD-FtsZ interaction. This binding displaces FtsA and/or ZipA, and more importantly, positions MinC(N) near the FtsZ polymers making it a more effective inhibitor.
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Affiliation(s)
- Bang Shen
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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36
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Abstract
Forces are important in biological systems for accomplishing key cell functions, such as motility, organelle transport, and cell division. Currently, known force generation mechanisms typically involve motor proteins. In bacterial cells, no known motor proteins are involved in cell division. Instead, a division ring (Z-ring) consists of mostly FtsZ, FtsA, and ZipA is used to exerting a contractile force. The mechanism of force generation in bacterial cell division is unknown. Using computational modeling, we show that Z-ring formation results from the colocalization of FtsZ and FtsA mediated by the favorable alignment of FtsZ polymers. The model predicts that the Z-ring undergoes a condensation transition from a low-density state to a high-density state and generates a sufficient contractile force to achieve division. FtsZ GTP hydrolysis facilitates monomer turnover during the condensation transition, but does not directly generate forces. In vivo fluorescence measurements show that FtsZ density increases during division, in accord with model results. The mechanism is akin to van der Waals picture of gas-liquid condensation, and shows that organisms can exploit microphase transitions to generate mechanical forces.
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37
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Handler AA, Lim JE, Losick R. Peptide inhibitor of cytokinesis during sporulation in Bacillus subtilis. Mol Microbiol 2008; 68:588-99. [PMID: 18284588 DOI: 10.1111/j.1365-2958.2008.06173.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cytokinesis in bacteria is mediated by the tubulin-like protein FtsZ, which forms a Z-ring at the division site. Using FtsZ as bait in a two-hybrid screen, we discovered a 40-amino-acid peptide, termed MciZ, from Bacillus subtilis that appeared to interact with FtsZ. Cells engineered to produce MciZ during growth formed aseptate filaments that lacked Z-rings. A mutant resistant to the toxic effects of MciZ during growth harboured an amino acid substitution near the GTP binding pocket of FtsZ. Synthetic MciZ inhibited the GTPase activity of FtsZ and its ability to polymerize. MciZ was produced during sporulation under the control of the transcription factor sigma(E). In the absence of MciZ, the mother-cell compartment of the sporangium aberrantly formed a Z-ring at a time in development when cytokinetic events normally have ceased. We conclude that MciZ is a previously unrecognized inhibitor of FtsZ that prevents inappropriate Z-ring formation during sporulation. MciZ showed little sequence similarity to other peptides in the databases, except the mouse antimicrobial peptide CRAMP, which we speculate works in part by inhibiting cytokinesis.
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Affiliation(s)
- Aaron A Handler
- The Biological Laboratories, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
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Investigation of regulation of FtsZ assembly by SulA and development of a model for FtsZ polymerization. J Bacteriol 2008; 190:2513-26. [PMID: 18245292 DOI: 10.1128/jb.01612-07] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In Escherichia coli FtsZ organizes into a cytoskeletal ring structure, the Z ring, which effects cell division. FtsZ is a GTPase, but the free energy of GTP hydrolysis does not appear to be used for generation of the constriction force, leaving open the question of the function of the GTPase activity of FtsZ. Here we study the mechanism by which SulA, an inhibitor of FtsZ induced during the SOS response, inhibits FtsZ function. We studied the effects of SulA on the in vitro activities of FtsZ, on Z rings in vivo, and on a kinetic model for FtsZ polymerization in silico. We found that the binding of SulA to FtsZ is necessary but not sufficient for inhibition of polymerization, since the assembly of FtsZ polymers in the absence of the GTPase activity was not inhibited by SulA. We developed a new model for FtsZ polymerization that accounts for the cooperativity of FtsZ and could account for cooperativity observed in other linear polymers. When SulA was included in the kinetic scheme, simulations revealed that SulA with strong affinity for FtsZ delayed, but did not prevent, the assembly of polymers when they were not hydrolyzing GTP. Furthermore, the simulations indicated that SulA controls the assembly of FtsZ by binding to a polymerization-competent form of the FtsZ molecule and preventing it from participating in assembly. In vivo stoichiometry of the disruption of Z rings by SulA suggests that FtsZ may undergo two cooperative transitions in forming the Z ring.
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39
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Abstract
The eukaryotic cytoskeleton appears to have evolved from ancestral precursors related to prokaryotic FtsZ and MreB. FtsZ and MreB show 40-50% sequence identity across different bacterial and archaeal species. Here I suggest that this represents the limit of divergence that is consistent with maintaining their functions for cytokinesis and cell shape. Previous analyses have noted that tubulin and actin are highly conserved across eukaryotic species, but so divergent from their prokaryotic relatives as to be hardly recognizable from sequence comparisons. One suggestion for this extreme divergence of tubulin and actin is that it occurred as they evolved very different functions from FtsZ and MreB. I will present new arguments favoring this suggestion, and speculate on pathways. Moreover, the extreme conservation of tubulin and actin across eukaryotic species is not due to an intrinsic lack of variability, but is attributed to their acquisition of elaborate mechanisms for assembly dynamics and their interactions with multiple motor and binding proteins. A new structure-based sequence alignment identifies amino acids that are conserved from FtsZ to tubulins. The highly conserved amino acids are not those forming the subunit core or protofilament interface, but those involved in binding and hydrolysis of GTP.
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Affiliation(s)
- Harold P Erickson
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710-3709, USA.
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40
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Abstract
Escherichia coli cells depleted of the conserved GTPase, ObgE, show early chromosome-partitioning defects and accumulate replicated chromosomes in which the terminus regions are colocalized. Cells lacking ObgE continue to initiate replication, with a normal ratio of the origin to terminus. Localization of the SeqA DNA binding protein, normally seen as punctate foci, however, was disturbed. Depletion of ObgE also results in cell filamentation, with polyploid DNA content. Depletion of ObgE did not cause lethality, and cells recovered fully after expression of ObgE was restored. We propose a model in which ObgE is required to license chromosome segregation and subsequent cell cycle events.
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Affiliation(s)
- James J Foti
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454-9110, USA
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41
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Larsen RA, Cusumano C, Fujioka A, Lim-Fong G, Patterson P, Pogliano J. Treadmilling of a prokaryotic tubulin-like protein, TubZ, required for plasmid stability in Bacillus thuringiensis. Genes Dev 2007; 21:1340-52. [PMID: 17510284 PMCID: PMC1877747 DOI: 10.1101/gad.1546107] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Prokaryotes rely on a distant tubulin homolog, FtsZ, for assembling the cytokinetic ring essential for cell division, but are otherwise generally thought to lack tubulin-like polymers that participate in processes such as DNA segregation. Here we characterize a protein (TubZ) from the Bacillus thuringiensis virulence plasmid pBtoxis, which is a member of the tubulin/FtsZ GTPase superfamily but is only distantly related to both FtsZ and tubulin. TubZ assembles dynamic, linear polymers that exhibit directional polymerization with plus and minus ends, movement by treadmilling, and a critical concentration for assembly. A point mutation (D269A) that alters a highly conserved catalytic residue within the T7 loop completely eliminates treadmilling and allows the formation of stable polymers at a much lower protein concentration than the wild-type protein. When expressed in trans, TubZ(D269A) coassembles with wild-type TubZ and significantly reduces the stability of pBtoxis, demonstrating a direct correlation between TubZ dynamics and plasmid maintenance. The tubZ gene is in an operon with tubR, which encodes a putative DNA-binding protein that regulates TubZ levels. Our results suggest that TubZ is representative of a novel class of prokaryotic cytoskeletal proteins important for plasmid stability that diverged long ago from the ancient tubulin/FtsZ ancestor.
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Affiliation(s)
- Rachel A. Larsen
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Christina Cusumano
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Akina Fujioka
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Grace Lim-Fong
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Paula Patterson
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Joe Pogliano
- Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
- Corresponding author.E-MAIL ; FAX (858) 822-1431
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42
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Vicente M, Hodgson J, Massidda O, Tonjum T, Henriques-Normark B, Ron EZ. The fallacies of hope: will we discover new antibiotics to combat pathogenic bacteria in time? FEMS Microbiol Rev 2006; 30:841-52. [PMID: 17064283 DOI: 10.1111/j.1574-6976.2006.00038.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
While newly developed technologies have revolutionized the classical approaches to combating infectious diseases, the difficulties associated with developing novel antimicrobials mean that these technologies have not yet been used to introduce new compounds into the market. The new technologies, including genomics and structural biology, open up exciting possibilities for the discovery of antibiotics. However, a substantial effort to pursue research, and moreover to incorporate the results into the production chain, is required in order to bring new antimicrobials to the final user. In the current scenario of emerging diseases and the rapid spread of antibiotic resistance, an active policy to support these requirements is vital. Otherwise, many valuable programmes may never be fully developed for lack of "interest" and funds (private and public). Will we react in time to avoid potential disaster?
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Affiliation(s)
- Miguel Vicente
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, Madrid, Spain.
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43
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Abstract
ftsZ is essential for cell division in many microorganisms. In Escherichia coli and Bacillus subtilis, FtsZ plays a role in ring formation at the leading edge of the cell division septum. An ftsZ homologue is present in the Borrelia burgdorferi genome (ftsZ(Bbu)). Its gene product (FtsZ(Bbu)) is strongly homologous to other bacterial FtsZ proteins, but its function has not been established. Because loss-of-function mutants of ftsZ(Bbu) might be lethal, the tetR/tetO system was adapted for regulated control of this gene in B. burgdorferi. Sixty-two nucleotides of an ftsZ(Bbu) antisense DNA sequence under the control of a tetracycline-responsive modified hybrid borrelial promoter were cloned into pKFSS1. This construct was electroporated into a B. burgdorferi host strain carrying a chromosomally located tetR under the control of the B. burgdorferi flaB promoter. After induction by anhydrotetracycline, expression of antisense ftsZ RNA resulted in generation of filamentous B. burgdorferi that were unable to divide and grew more slowly than uninduced cells. To determine whether FtsZ(Bbu) could interfere with the function of E. coli FtsZ, ftsZ(Bbu) was amplified from chromosomal DNA and placed under the control of the tetracycline-regulated hybrid promoter. After introduction of the construct into E. coli and induction with anhydrotetracycline, overexpression of ftsZ(Bbu) generated a filamentous phenotype. This suggested interference of ftsZ(Bbu) with E. coli FtsZ function and confirmed the role of ftsZ(Bbu) in cell division. This is the first report of the generation of a B. burgdorferi conditional lethal mutant equivalent by tetracycline-controlled expression of antisense RNA.
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Affiliation(s)
- Lydia Dubytska
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA.
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Nogales E, Wang HW. Structural mechanisms underlying nucleotide-dependent self-assembly of tubulin and its relatives. Curr Opin Struct Biol 2006; 16:221-9. [PMID: 16549346 DOI: 10.1016/j.sbi.2006.03.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 02/07/2006] [Accepted: 03/10/2006] [Indexed: 10/24/2022]
Abstract
The alphabeta-tubulin dimer assembles into microtubules, essential polymers in all eukaryotic cells. Microtubules are highly dynamic, a property that derives from tubulin's GTPase activity. Both the bacterial homolog, FtsZ, and the recently discovered bacterial tubulins from Prosthecobacter self-assemble in a nucleotide-dependent manner into protofilaments similar to those that form the microtubule wall. A number of structural studies of alphabeta-tubulin, gamma-tubulin (the isoform involved in microtubule nucleation), FtsZ and bacterial tubulin, in a variety of nucleotide and polymerization states, have been reported in the past few years. These studies have revealed the similarities and differences between these structures and their possible functional implications. In particular, a two-state mechanism has been proposed for the recycling of alphabeta-tubulin during the microtubule disassembly-assembly cycle; this mechanism may be unique to eukaryotic dimeric tubulin and the microtubule structure.
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Affiliation(s)
- Eva Nogales
- Howard Hughes Medical Institute, Molecular and Cell Biology Department, University of California Berkeley and Lawrence Berkeley National Laboratory, 355 LSA, University of California Berkeley, Berkeley, CA 94720-3200, USA.
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45
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Abe T, Hashimoto T. Altered microtubule dynamics by expression of modified alpha-tubulin protein causes right-handed helical growth in transgenic Arabidopsis plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 43:191-204. [PMID: 15998306 DOI: 10.1111/j.1365-313x.2005.02442.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The proper organization of cortical microtubule arrays is essential for anisotropic growth in plants but how distinct array patterns are formed is not understood. Here, we report a relationship between microtubule dynamics and array organization using transgenic plants expressing modified tubulins. When green fluorescent protein (GFP) or a hemaglutinin epitope tag was fused to the N-terminus of tubulins and expressed in Arabidopsis plants, these tubulins were incorporated into microtubules along with endogenous tubulins. Plants expressing the modified beta-tubulins were phenotypically normal and possessed transversely oriented cortical arrays in the epidermal cells of the root elongation zone; however, the expression of modified alpha-tubulins caused right-handed helical growth, increased trichome branching, and a shallow left-handed (S-form) helical array organization. In cells expressing the modified alpha-tubulins, microtubule dynamicity was suppressed and polymerization was promoted, and GFP-EB1 (End Binding 1) labeled larger regions of the microtubule end more frequently, when compared with control cells. We propose that the N-terminal appendage introduced into alpha-tubulin inhibits GTP hydrolysis, thus producing polymerization-prone microtubules with an extended GTP cap. Consistent with this interpretation, plants expressing an alpha-tubulin mutated in the GTPase-activating domain exhibited similar microtubule properties, with regard to dynamics and the localization of GFP-EB1, and showed right-handed helical growth.
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Affiliation(s)
- Tatsuya Abe
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan
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46
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Downing KH. Structural basis for the action of drugs that affect microtubule dynamics. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728222.4.2.219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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47
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Addinall SG, Small E, Whitaker D, Sturrock S, Donachie WD, Khattar MM. New temperature-sensitive alleles of ftsZ in Escherichia coli. J Bacteriol 2005; 187:358-65. [PMID: 15601720 PMCID: PMC538815 DOI: 10.1128/jb.187.1.358-365.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We isolated five new temperature-sensitive alleles of the essential cell division gene ftsZ in Escherichia coli, using P1-mediated, localized mutagenesis. The five resulting single amino acid changes (Gly109-->Ser109 for ftsZ6460, Ala129-->Thr129 for ftsZ972, Val157-->Met157 for ftsZ2066, Pro203-->Leu203 for ftsZ9124, and Ala239-->Val239 for ftsZ2863) are distributed throughout the FtsZ core region, and all confer a lethal cell division block at the nonpermissive temperature of 42 degrees C. In each case the division block is associated with loss of Z-ring formation such that fewer than 2% of cells show Z rings at 42 degrees C. The ftsZ9124 and ftsZ6460 mutations are of particular interest since both result in abnormal Z-ring formation at 30 degrees C and therefore cause significant defects in FtsZ polymerization, even at the permissive temperature. Neither purified FtsZ9124 nor purified FtsZ6460 exhibited polymerization when it was assayed by light scattering or electron microscopy, even in the presence of calcium or DEAE-dextran. Hence, both mutations also cause defects in FtsZ polymerization in vitro. Interestingly, FtsZ9124 has detectable GTPase activity, although the activity is significantly reduced compared to that of the wild-type FtsZ protein. We demonstrate here that unlike expression of ftsZ84, multicopy expression of the ftsZ6460, ftsZ972, and ftsZ9124 alleles does not complement the respective lethalities at the nonpermissive temperature. In addition, all five new mutant FtsZ proteins are stable at 42 degrees C. Therefore, the novel isolates carrying single ftsZ(Ts) point mutations, which are the only such strains obtained since isolation of the classical ftsZ84 mutation, offer significant opportunities for further genetic characterization of FtsZ and its role in cell division.
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48
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Ruiz F, Dupuis-Williams P, Klotz C, Forquignon F, Bergdoll M, Beisson J, Koll F. Genetic evidence for interaction between eta- and beta-tubulins. EUKARYOTIC CELL 2004; 3:212-20. [PMID: 14871951 PMCID: PMC329518 DOI: 10.1128/ec.3.1.212-220.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The thermosensitive allelic mutations sm19-1 and sm19-2 of Paramecium tetraurelia cause defective basal body duplication: growth at the nonpermissive temperature yields smaller and smaller cells with fewer and fewer basal bodies. Complementation cloning of the SM19 gene identified a new tubulin, eta-tubulin, showing low homology with each of the other five tubulins, alpha to epsilon, characterized in P. tetraurelia. In order to analyze eta-tubulin functions, we used a genetic approach to identify interacting molecules. Among a series of extragenic suppressors of the sm19-1 mutation, the su3-1 mutation was characterized as an E288K substitution in the beta-PT2 gene coding for a beta-tubulin, while the mutation nocr1 conferring nocodazole resistance and localized in another beta-tubulin gene, beta-PT3, was shown to enhance the mutant phenotype. The interaction between eta-tubulin and microtubules, revealed by genetic data, is supported by two further types of evidence: first, the mutant phenotype is rescued by taxol, which stabilizes microtubules; second, molecular modeling suggests that eta-tubulin, like gamma- and delta-tubulins, might be a microtubule minus-end capping molecule. The likely function of eta-tubulin as part of a complex specifically involved in basal body biogenesis is discussed.
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Affiliation(s)
- F Ruiz
- Centre de Génétique Moléculaire, CNRS, 91198 Gif-sur-Yvette, France
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49
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Downing KH, Nogales E. Crystallographic structure of tubulin: implications for dynamics and drug binding. Cell Struct Funct 2004; 24:269-75. [PMID: 15216882 DOI: 10.1247/csf.24.269] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The structure of tubulin, recently solved by electron crystallography, has given a first look at the molecular basis for some of the properties of tubulin and microtubules that have been observed over the last decades. We discuss how the structure relates to some of these properties, and how inferences about drug binding sites can explain some of the effects of the drugs on tubulin. Microtubules can form a highly dynamic system that requires careful tuning of the stability and properties of tubulin and its interactions with its many ligands. Understanding these interactions can provide fundamental information on the regulation of the microtubule system.
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Affiliation(s)
- K H Downing
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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50
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Zhao Y, Hammond RW, Lee IM, Roe BA, Lin S, Davis RE. Cell division gene cluster in Spiroplasma kunkelii: functional characterization of ftsZ and the first report of ftsA in mollicutes. DNA Cell Biol 2004; 23:127-34. [PMID: 15000753 DOI: 10.1089/104454904322759948] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Spiroplasma kunkelii is a helical, wall-less bacterium that causes corn stunt disease. In adaptation to its phloem-inhabiting parasitic lifestyle, the bacterium has undergone a reductive evolutionary process and, as a result, possesses a compact genome with a gene set approaching the minimal complement necessary for multiplication and pathogenesis. We cloned a much-reduced cell division gene cluster from S. kunkelii and functionally characterized the key division gene, ftsZ(sk). The 1236-bp open reading frame of ftsZ(sk) is capable of encoding a protein with a calculated molecular mass of 44.1 kDa. Protein sequence alignment revealed that FtsZ(sk) is remarkably similar to FtsZ proteins from other eubacteria, and possesses the conserved GTP-binding and hydrolyzing motifs. We demonstrated that overexpression of ftsZ(sk) in Escherichia coli causes transgression of the host cell division, resulting in a filamentous phenotype. We also report, for the first time, the presence of a ftsA gene in the cell division cluster of a mollicute species.
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Affiliation(s)
- Yan Zhao
- Molecular Plant Pathology Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland, USA
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