1
|
Uneme M, Ishikawa K, Furuta K, Yamashita A, Kaito C. Overexpression of the flagellar motor protein MotB sensitizes Bacillus subtilis to aminoglycosides in a motility-independent manner. PLoS One 2024; 19:e0300634. [PMID: 38669243 PMCID: PMC11051680 DOI: 10.1371/journal.pone.0300634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 03/02/2024] [Indexed: 04/28/2024] Open
Abstract
The flagellar motor proteins, MotA and MotB, form a complex that rotates the flagella by utilizing the proton motive force (PMF) at the bacterial cell membrane. Although PMF affects the susceptibility to aminoglycosides, the effect of flagellar motor proteins on the susceptibility to aminoglycosides has not been investigated. Here, we found that MotB overexpression increased susceptibility to aminoglycosides, such as kanamycin and gentamicin, in Bacillus subtilis without affecting swimming motility. MotB overexpression did not affect susceptibility to ribosome-targeting antibiotics other than aminoglycosides, cell wall-targeting antibiotics, DNA synthesis-inhibiting antibiotics, or antibiotics inhibiting RNA synthesis. Meanwhile, MotB overexpression increased the susceptibility to aminoglycosides even in the motA-deletion mutant, which lacks swimming motility. Overexpression of the MotB mutant protein carrying an amino acid substitution at the proton-binding site (D24A) resulted in the loss of the enhanced aminoglycoside-sensitive phenotype. These results suggested that MotB overexpression sensitizes B. subtilis to aminoglycosides in a motility-independent manner. Notably, the aminoglycoside-sensitive phenotype induced by MotB requires the proton-binding site but not the MotA/MotB complex formation.
Collapse
Affiliation(s)
- Mio Uneme
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazuya Ishikawa
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazuyuki Furuta
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Atsuko Yamashita
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Chikara Kaito
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
2
|
Terahara N, Namba K, Minamino T. Dynamic exchange of two types of stator units in Bacillus subtilis flagellar motor in response to environmental changes. Comput Struct Biotechnol J 2020; 18:2897-2907. [PMID: 33163150 PMCID: PMC7595845 DOI: 10.1016/j.csbj.2020.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 11/23/2022] Open
Abstract
Bacteria can migrate towards more suitable environments by rotating flagella that are under the control of sensory signal transduction networks. The bacterial flagellum is composed of the long helical filament functioning as a propeller, the flexible hook as a universal joint and the basal body as a rotary motor powered by ion motive force across the cell membrane. The flagellar motor consists of a rotor and multiple stator units, each of which couples the ion flow through its ion channel with force generation. The flagellar building blocks and motor proteins are highly conserved among bacterial species, but structural and functional diversity of flagella has also been revealed. It has been reported that the structure and function of the flagellar motor of a Gram-positive bacterium, Bacillus subtilis, differ from those of Escherichia coli and Salmonella. The flagellar motor of the B. subtilis BR151MA strain possesses two distinct types of stator complexes, H+-type MotAB and Na+-type MotPS, around the rotor. These two types of stator units dynamically assemble to and disassemble from the rotor in response to environmental changes such as viscosity and external Na+ concentrations. In this mini-review article, we describe our recent understanding of the structure and dynamics of the B. subtilis flagellar motor.
Collapse
Affiliation(s)
- Naoya Terahara
- Department of Physics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Keiichi Namba
- Graduate School of Frontier Bioscience, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- RIKEN Spring-8 Center and Center for Biosystems Dynamics Research, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tohru Minamino
- Graduate School of Frontier Bioscience, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
3
|
Metabolites Produced by Kaistia sp. 32K Promote Biofilm Formation in Coculture with Methylobacterium sp. ME121. BIOLOGY 2020; 9:biology9090287. [PMID: 32933123 PMCID: PMC7563137 DOI: 10.3390/biology9090287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 02/01/2023]
Abstract
Previously, we reported that the coculture of motile Methylobacterium sp. ME121 and non-motile Kaistia sp. 32K, isolated from the same soil sample, displayed accelerated motility of strain ME121 due to an extracellular polysaccharide (EPS) produced by strain 32K. Since EPS is a major component of biofilms, we aimed to investigate the biofilm formation in cocultures of the two strains. The extent of biofilm formation was measured by a microtiter dish assay with the dye crystal violet. A significant increase in the amount of biofilm was observed in the coculture of the two strains, as compared to that of the monocultures, which could be due to a metabolite produced by strain 32K. However, in the coculture with strain 32K, using Escherichia coli or Pseudomonas aeruginosa, there was no difference in the amount of biofilm formation as compared with the monoculture. Elevated biofilm formation was also observed in the coculture of strain ME121 with Kaistia adipata, which was isolated from a different soil sample. Methylobacterium radiotolerans, isolated from another soil sample, showed a significant increase in biofilm formation when cocultured with K. adipata, but not with strain 32K. We also found that the culture supernatants of strains 32K and K. adipata accelerated the motility of strains ME121 and M. radiotolerans, wherein culture supernatant of K. adipata significantly increased the motility of M. radiotolerans, as compared to that by the culture supernatant of strain 32K. These results indicated that there was a positive relationship between accelerated motility and increased biofilm formation in Methylobacterium spp. This is the first study to report that the metabolites from Kaistia spp. could specifically modulate the biofilm-forming ability of Methylobacterium spp. Methylobacterium spp. biofilms are capable of inhibiting the biofilm formation of mycobacteria, which are opportunistic pathogens that cause problems in infectious diseases. Thus, the metabolites from the culture supernatant of Kaistia spp. have the potential to contribute to the environment in which increased biofilm production of Methylobacterium is desired.
Collapse
|
4
|
Naganawa S, Ito M. MotP Subunit is Critical for Ion Selectivity and Evolution of a K +-Coupled Flagellar Motor. Biomolecules 2020; 10:biom10050691. [PMID: 32365619 PMCID: PMC7277484 DOI: 10.3390/biom10050691] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 01/03/2023] Open
Abstract
The bacterial flagellar motor is a sophisticated nanomachine embedded in the cell envelope. The flagellar motor is driven by an electrochemical gradient of cations such as H+, Na+, and K+ through ion channels in stator complexes embedded in the cell membrane. The flagellum is believed to rotate as a result of electrostatic interaction forces between the stator and the rotor. In bacteria of the genus Bacillus and related species, the single transmembrane segment of MotB-type subunit protein (MotB and MotS) is critical for the selection of the H+ and Na+ coupling ions. Here, we constructed and characterized several hybrid stators combined with single Na+-coupled and dual Na+- and K+-coupled stator subunits, and we report that the MotP subunit is critical for the selection of K+. This result suggested that the K+ selectivity of the MotP/MotS complexes evolved from the single Na+-coupled stator MotP/MotS complexes. This finding will promote the understanding of the evolution of flagellar motors and the molecular mechanisms of coupling ion selectivity.
Collapse
Affiliation(s)
- Shun Naganawa
- Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan;
| | - Masahiro Ito
- Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan;
- Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585, Japan
- Correspondence: ; Tel.: +81-276-82-9202
| |
Collapse
|
5
|
Usui Y, Wakabayashi Y, Shimizu T, Tahara YO, Miyata M, Nakamura A, Ito M. A Factor Produced by Kaistia sp. 32K Accelerated the Motility of Methylobacterium sp. ME121. Biomolecules 2020; 10:biom10040618. [PMID: 32316239 PMCID: PMC7226442 DOI: 10.3390/biom10040618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/23/2022] Open
Abstract
Motile Methylobacterium sp. ME121 and non-motile Kaistia sp. 32K were isolated from the same soil sample. Interestingly, ME121 was significantly more motile in the coculture of ME121 and 32K than in the monoculture of ME121. This advanced motility of ME121 was also observed in the 32K culture supernatant. A swimming acceleration factor, which we named the K factor, was identified in the 32K culture supernatant, purified, characterized as an extracellular polysaccharide (5–10 kDa), and precipitated with 70% ethanol. These results suggest the possibility that the K factor was directly or indirectly sensed by the flagellar stator, accelerating the flagellar rotation of ME121. To the best of our knowledge, no reports describing an acceleration in motility due to coculture with two or more types of bacteria have been published. We propose a mechanism by which the increase in rotational force of the ME121 flagellar motor is caused by the introduction of the additional stator into the motor by the K factor.
Collapse
Affiliation(s)
- Yoshiaki Usui
- Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan; (Y.U.); (Y.W.)
| | - Yuu Wakabayashi
- Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan; (Y.U.); (Y.W.)
| | - Tetsu Shimizu
- Faculty of Life and Environmental Sciences, and Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan; (T.S.); (A.N.)
| | - Yuhei O. Tahara
- Department of Biology, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan; (Y.O.T.); (M.M.)
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka 558-8585, Japan
| | - Makoto Miyata
- Department of Biology, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan; (Y.O.T.); (M.M.)
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka 558-8585, Japan
| | - Akira Nakamura
- Faculty of Life and Environmental Sciences, and Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan; (T.S.); (A.N.)
| | - Masahiro Ito
- Graduate School of Life Sciences, Toyo University, Oura-gun, Gunma 374-0193, Japan; (Y.U.); (Y.W.)
- Bio-Nano Electronics Research Centre, Toyo University, Kawagoe, Saitama 350-8585, Japan
- Correspondence: ; Tel.: +81-273-82-9202
| |
Collapse
|
6
|
Terahara N, Kodera N, Uchihashi T, Ando T, Namba K, Minamino T. Na +-induced structural transition of MotPS for stator assembly of the Bacillus flagellar motor. SCIENCE ADVANCES 2017; 3:eaao4119. [PMID: 29109979 PMCID: PMC5665596 DOI: 10.1126/sciadv.aao4119] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/06/2017] [Indexed: 05/03/2023]
Abstract
The bacterial flagellar motor consists of a rotor and a dozen stator units and regulates the number of active stator units around the rotor in response to changes in the environment. The MotPS complex is a Na+-type stator unit in the Bacillus subtilis flagellar motor and binds to the peptidoglycan layer through the peptidoglycan-binding (PGB) domain of MotS to act as the stator. The MotPS complex is activated in response to an increase in the Na+ concentration in the environment, but the mechanism of this activation has remained unknown. We report that activation occurs by a Na+-induced folding and dimer formation of the PGB domain of MotS, as revealed in real-time imaging by high-speed atomic force microscopy. The MotPS complex showed two distinct ellipsoid domains connected by a flexible linker. A smaller domain, corresponding to the PGB domain, became structured and unstructured in the presence and absence of 150 mM NaCl, respectively. When the amino-terminal portion of the PGB domain adopted a partially stretched conformation in the presence of NaCl, the center-to-center distance between these two domains increased by up to 5 nm, allowing the PGB domain to reach and bind to the peptidoglycan layer. We propose that assembly of the MotPS complex into a motor proceeds by means of Na+-induced structural transitions of its PGB domain.
Collapse
Affiliation(s)
- Naoya Terahara
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Noriyuki Kodera
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa 920-1192, Japan
| | - Takayuki Uchihashi
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa 920-1192, Japan
- Department of Physics, Kanazawa University, Kanazawa 920-1192, Japan
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Toshio Ando
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa 920-1192, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Goban-cho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- Quantitative Biology Center, RIKEN, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- Corresponding author. (T.M.); (K.N.)
| | - Tohru Minamino
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- Corresponding author. (T.M.); (K.N.)
| |
Collapse
|
7
|
Juhas M, Ajioka JW. Flagellar region 3b supports strong expression of integrated DNA and the highest chromosomal integration efficiency of the Escherichia coli flagellar regions. Microb Biotechnol 2016; 8:726-38. [PMID: 26074421 PMCID: PMC4476827 DOI: 10.1111/1751-7915.12296] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 11/28/2022] Open
Abstract
The Gram-negative bacterium Escherichia coli is routinely used as the chassis for a variety of biotechnology and synthetic biology applications. Identification and analysis of reliable chromosomal integration and expression target loci is crucial for E. coli engineering. Chromosomal loci differ significantly in their ability to support integration and expression of the integrated genetic circuits. In this study, we investigate E. coli K12 MG1655 flagellar regions 2 and 3b. Integration of the genetic circuit into seven and nine highly conserved genes of the flagellar regions 2 (motA, motB, flhD, flhE, cheW, cheY and cheZ) and 3b (fliE, F, G, J, K, L, M, P, R), respectively, showed significant variation in their ability to support chromosomal integration and expression of the integrated genetic circuit. While not reducing the growth of the engineered strains, the integrations into all 16 target sites led to the loss of motility. In addition to high expression, the flagellar region 3b supports the highest efficiency of integration of all E. coli K12 MG1655 flagellar regions and is therefore potentially the most suitable for the integration of synthetic genetic circuits.
Collapse
Affiliation(s)
- Mario Juhas
- Department of Pathology, University of Cambridge, Tennis Court Road, CB2 1QP, Cambridge, UK
| | - James W Ajioka
- Department of Pathology, University of Cambridge, Tennis Court Road, CB2 1QP, Cambridge, UK
| |
Collapse
|