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Cho SY, Oh HB, Yoon SI. Hexameric structure of the flagellar master regulator FlhDC from Cupriavidus necator and its interaction with flagellar promoter DNA. Biochem Biophys Res Commun 2023; 672:97-102. [PMID: 37343320 DOI: 10.1016/j.bbrc.2023.06.033] [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: 05/23/2023] [Accepted: 06/09/2023] [Indexed: 06/23/2023]
Abstract
Bacterial flagella are assembled with ∼30 different proteins in a defined order via diverse regulatory systems. In gram-negative bacteria from the Gammaproteobacteria and Betaproteobacteria classes, the transcription of flagellar genes is strictly controlled by the master regulator FlhDC. In Gammaproteobacteria species, the FlhDC complex has been shown to activate flagellar expression by directly interacting with the promoter region in flagellar genes. To obtain the DNA-binding mechanism of FlhDC and determine the conserved and distinct structural features of Betaproteobacteria and Gammaproteobacteria FlhDCs that are necessary for their functions, we determined the crystal structure of Betaproteobacteria Cupriavidus necator FlhDC (cnFlhDC) and biochemically analyzed its DNA-binding capacity. cnFlhDC specifically recognized the promoter DNA of the class II flagellar genes flgB and flhB. cnFlhDC adopts a ring-like heterohexameric structure (cnFlhD4C2) and harbors two Zn-Cys clusters, as observed for Gammaproteobacteria Escherichia coli FlhDC (ecFlhDC). The cnFlhDC structure exhibits positively charged surfaces across two FlhDC subunits as a putative DNA-binding site. Noticeably, the positive patch of cnFlhDC is continuous, in contrast to the separated patches of ecFlhDC. Moreover, the ternary intersection of cnFlhD4C2 behind the Zn-Cys cluster forms a unique protruding neutral structure, which is replaced with a charged cavity in the ecFlhDC structure.
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Affiliation(s)
- So Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Han Byeol Oh
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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Ko KY, Park SC, Cho SY, Yoon SI. Structural analysis of carboxyspermidine dehydrogenase from Helicobacter pylori. Biochem Biophys Res Commun 2022; 635:210-217. [DOI: 10.1016/j.bbrc.2022.10.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022]
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Ki DU, Song WS, Yoon SI. Structural and biochemical analysis of the GDSL-family esterase CJ0610C from Campylobacter jejuni. Biochem Biophys Res Commun 2022; 631:124-129. [DOI: 10.1016/j.bbrc.2022.09.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 09/18/2022] [Indexed: 11/02/2022]
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Cho SY, Na HW, Oh H, Kwak YM, Song WS, Park S, Jeon WJ, Cho H, Oh BC, Park J, Kang S, Lee GS, Yoon SI. Structural basis of flagellar motility regulation by the MogR repressor and the GmaR antirepressor in Listeria monocytogenes. Nucleic Acids Res 2022; 50:11315-11330. [PMID: 36283692 PMCID: PMC9638930 DOI: 10.1093/nar/gkac815] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 08/01/2022] [Accepted: 09/11/2022] [Indexed: 08/27/2023] Open
Abstract
The pathogenic Listeria monocytogenes bacterium produces the flagellum as a locomotive organelle at or below 30°C outside the host, but it halts flagellar expression at 37°C inside the human host to evade the flagellum-induced immune response. Listeria monocytogenes GmaR is a thermosensor protein that coordinates flagellar expression by binding the master transcriptional repressor of flagellar genes (MogR) in a temperature-responsive manner. To understand the regulatory mechanism whereby GmaR exerts the antirepression activity on flagellar expression, we performed structural and mutational analyses of the GmaR-MogR system. At or below 30°C, GmaR exists as a functional monomer and forms a circularly enclosed multidomain structure via an interdomain interaction. GmaR in this conformation recognizes MogR using the C-terminal antirepressor domain in a unique dual binding mode and mediates the antirepressor function through direct competition and spatial restraint mechanisms. Surprisingly, at 37°C, GmaR rapidly forms autologous aggregates that are deficient in MogR neutralization capabilities.
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Affiliation(s)
- So Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hye-won Na
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Han Byeol Oh
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Yun Mi Kwak
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Wan Seok Song
- Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Sun Cheol Park
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Wook-Jong Jeon
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hongbaek Cho
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Byung-Chul Oh
- Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon 406-840, Republic of Korea
| | - Jeongho Park
- College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Seung Goo Kang
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Geun-Shik Lee
- College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Sung-il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
- Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea
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Crystal Structure of the Recombination Mediator Protein RecO from Campylobacter jejuni and Its Interaction with DNA and a Zinc Ion. Int J Mol Sci 2022; 23:ijms23179667. [PMID: 36077065 PMCID: PMC9456098 DOI: 10.3390/ijms23179667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/23/2022] Open
Abstract
Homologous recombination is involved in repairing DNA damage, contributing to maintaining the integrity and stability of viral and cellular genomes. In bacteria, the recombination mediator proteins RecO and RecR are required to load the RecA recombinase on ssDNA for homologous recombination. To structurally and functionally characterize RecO, we determined the crystal structure of RecO from Campylobacter jejuni (cjRecO) at a 1.8 Å resolution and biochemically assessed its capacity to interact with DNA and a metal ion. cjRecO folds into a curved rod-like structure that consists of an N-terminal domain (NTD), C-terminal domain (CTD), and Zn2+-binding domain (ZnD). The ZnD at the end of the rod-like structure coordinates three cysteine residues and one histidine residue to accommodate a Zn2+ ion. Based on an extensive comparative analysis of RecO structures and sequences, we propose that the Zn2+-binding consensus sequence of RecO is CxxC…C/HxxC/H/D. The interaction with Zn2+ is indispensable for the protein stability of cjRecO but does not seem to be required for the recombination mediator function. cjRecO also interacts with ssDNA as part of its biological function, potentially using the positively charged patch in the NTD and CTD. However, cjRecO displays a low ssDNA-binding affinity, suggesting that cjRecO requires RecR to efficiently recognize ssDNA for homologous recombination.
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Structural and biochemical analyses of the flagellar expression regulator DegU from Listeria monocytogenes. Sci Rep 2022; 12:10856. [PMID: 35798759 PMCID: PMC9263151 DOI: 10.1038/s41598-022-14459-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 06/07/2022] [Indexed: 11/24/2022] Open
Abstract
Listeria monocytogenes is a pathogenic bacterium that produces flagella, the locomotory organelles, in a temperature-dependent manner. At 37 °C inside humans, L. monocytogenes employs MogR to repress the expression of flagellar proteins, thereby preventing the production of flagella. However, in the low-temperature environment outside of the host, the antirepressor GmaR inactivates MogR, allowing flagellar formation. Additionally, DegU is necessary for flagellar expression at low temperatures. DegU transcriptionally activates the expression of GmaR and flagellar proteins by binding the operator DNA in the fliN-gmaR promoter as a response regulator of a two-component regulatory system. To determine the DegU-mediated regulation mechanism, we performed structural and biochemical analyses on the recognition of operator DNA by DegU. The DegU-DNA interaction is primarily mediated by a C-terminal DNA-binding domain (DBD) and can be fortified by an N-terminal receiver domain (RD). The DegU DBD adopts a tetrahelical helix-turn-helix structure and assembles into a dimer. The DegU DBD dimer recognizes the operator DNA using a positive patch. Unexpectedly, unlike typical response regulators, DegU interacts with operator DNA in both unphosphorylated and phosphorylated states with similar binding affinities. Therefore, we conclude that DegU is a noncanonical response regulator that is constitutively active irrespective of phosphorylation.
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Structural analysis of the virulence gene protein IceA2 from Helicobacter pylori. Biochem Biophys Res Commun 2022; 612:162-168. [DOI: 10.1016/j.bbrc.2022.04.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 04/20/2022] [Indexed: 11/22/2022]
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Oh HB, Lee KC, Park SC, Song WS, Yoon SI. Structural analysis of the dNTP triphosphohydrolase PA1124 from Pseudomonas aeruginosa. Biochem Biophys Res Commun 2021; 589:78-84. [PMID: 34894560 DOI: 10.1016/j.bbrc.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022]
Abstract
dNTP triphosphohydrolase (TPH) belongs to the histidine/aspartate (HD) superfamily and catalyzes the hydrolysis of dNTPs into 2'-deoxyribonucleoside and inorganic triphosphate. TPHs are required for cellular dNTP homeostasis and DNA replication fidelity and are employed as a host defense mechanism. PA1124 from the pathogenic Pseudomonas aeruginosa bacterium functions as a dGTP and dTTP triphosphohydrolase. To reveal how PA1124 drives dNTP hydrolysis and is regulated, we performed a structural study of PA1124. PA1124 assembles into a hexameric architecture as a trimer of dimers. Each monomer has an interdomain dent where a metal ion is coordinated by conserved histidine and aspartate residues. A structure-based comparative analysis suggests that PA1124 accommodates the dNTP substrate into the interdomain dent near the metal ion. Interestingly, PA1124 interacts with ssDNA, presumably as an allosteric regulator, using a positively charged intersubunit cleft that is generated via dimerization. Furthermore, our phylogenetic analysis highlights similar or distinct oligomerization profiles across the TPH family.
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Affiliation(s)
- Han Byeol Oh
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, South Korea
| | - Kang-Cheon Lee
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, South Korea
| | - Sun Cheol Park
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, South Korea
| | - Wan Seok Song
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, South Korea; Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, 24341, South Korea.
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, South Korea; Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, 24341, South Korea.
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