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Complementary Roles of Two DNA Protection Proteins from Deinococcus geothermalis. Int J Mol Sci 2022; 24:ijms24010469. [PMID: 36613913 PMCID: PMC9820295 DOI: 10.3390/ijms24010469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
The roles of two interrelated DNA protection protein in starved cells (Dps)-putative Dps Dgeo_0257 and Dgeo_0281-as orthologous proteins to DrDps1 for DNA binding, protection, and metal ion sensing were characterised in a Deinococcus geothermalis strain. Dgeo_0257 exhibited high DNA-binding affinity and formed a multimeric structure but lacked the conserved amino acid sequence for ferroxidase activity. In contrast, the Dgeo_0281 (DgDps1) protein was abundant in the early exponential phase, had a lower DNA-binding activity than Dgeo_0257, and was mainly observed in its monomeric or dimeric forms. Electrophoretic mobility shift assays demonstrated that both purified proteins bound nonspecifically to DNA, and their binding ability was affected by certain metal ions. For example, in the presence of ferrous and ferric ions, neither Dgeo_0257 nor Dgeo_0281 could readily bind to DNA. In contrast, both proteins exhibited more stable DNA binding in the presence of zinc and manganese ions. Mutants in which the dps gene was disrupted exhibited higher sensitivity to oxidative stress than the wild-type strain. Furthermore, the expression levels of each gene showed an opposite correlation under H2O2 treatment conditions. Collectively, these findings indicate that the putative Dps Dgeo_0257 and DgDps1 from D. geothermalis are involved in DNA binding and protection in complementary interplay ways compared to known Dps.
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Flint A, Stintzi A, Saraiva LM. Oxidative and nitrosative stress defences of Helicobacter and Campylobacter species that counteract mammalian immunity. FEMS Microbiol Rev 2016; 40:938-960. [PMID: 28201757 PMCID: PMC5091033 DOI: 10.1093/femsre/fuw025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/29/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022] Open
Abstract
Helicobacter and Campylobacter species are Gram-negative microaerophilic host-associated heterotrophic bacteria that invade the digestive tract of humans and animals. Campylobacter jejuni is the major worldwide cause of foodborne gastroenteritis in humans, while Helicobacter pylori is ubiquitous in over half of the world's population causing gastric and duodenal ulcers. The colonisation of the gastrointestinal system by Helicobacter and Campylobacter relies on numerous cellular defences to sense the host environment and respond to adverse conditions, including those imposed by the host immunity. An important antimicrobial tool of the mammalian innate immune system is the generation of harmful oxidative and nitrosative stresses to which pathogens are exposed during phagocytosis. This review summarises the regulators, detoxifying enzymes and subversion mechanisms of Helicobacter and Campylobacter that ultimately promote the successful infection of humans.
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Affiliation(s)
- Annika Flint
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica, NOVA, Av. da República, 2780-157 Oeiras, Portugal
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Sanchuki HBS, Valdameri G, Moure VR, Rodriguez JA, Pedrosa FO, Souza EM, Korolik V, Ribeiro RR, Huergo LF. Conserved histidine residues at the ferroxidase centre of the Campylobacter jejuni Dps protein are not strictly required for metal binding and oxidation. MICROBIOLOGY-SGM 2015; 162:156-163. [PMID: 26555736 DOI: 10.1099/mic.0.000210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Iron is an essential micronutrient for living organisms as it is involved in a broad variety of important biological processes. However, free iron inside the cell could be potentially toxic, generating hydroxyl radicals through the Fenton reaction. Dps (DNA-binding protein from starved cells) belongs to a subfamily of ferritins and can store iron atoms inside the dodecamer. The presence of a ferroxidase centre, composed of highly conserved residues, is a signature of this protein family. In this study, we analysed the role of two conserved histidine residues (H25 and H37) located at the ferroxidase centre of the Campylobacter jejuni Dps protein by replacing them with glycine residues. The C. jejuni H25G/H37G substituted variant showed reduced iron binding and ferroxidase activities in comparison with wt Dps, while DNA-binding activity remained unaffected. We also found that both CjDps wt and CjDps H25G/H37G were able to bind manganese atoms. These results indicate that the H25 and H37 residues at the ferroxidase centre of C. jejuni Dps are not strictly required for metal binding and oxidation.
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Affiliation(s)
- Heloisa B S Sanchuki
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Glaucio Valdameri
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Vivian R Moure
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Jorge A Rodriguez
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C. Guadalajara, Mexico
| | - Fábio O Pedrosa
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Emanuel M Souza
- Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
| | - Victoria Korolik
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | | | - Luciano F Huergo
- Setor Litoral, UFPR, Matinhos, PR, Brazil.,Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Brazil
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