1
|
Williams SM, Chatterji D. Dps Functions as a Key Player in Bacterial Iron Homeostasis. ACS OMEGA 2023; 8:34299-34309. [PMID: 37779979 PMCID: PMC10536872 DOI: 10.1021/acsomega.3c03277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/24/2023] [Indexed: 10/03/2023]
Abstract
Iron plays a vital role in the maintenance of life, being central to various cellular processes, from respiration to gene regulation. It is essential for iron to be stored in a nontoxic and readily available form. DNA binding proteins under starvation (Dps) belong to the ferritin family of iron storage proteins and are adept at storing iron in their hollow protein shells. Existing solely in prokaryotes, these proteins have the additional functions of DNA binding and protection from oxidative stress. Iron storage proteins play a functional role in storage, release, and transfer of iron and therefore are central to the optimal functioning of iron homeostasis. Here we review the multifarious properties of Dps through relevant biochemical and structural studies with a focus on iron storage and ferroxidation. We also examine the role of Dps as a possible candidate as an iron donor to iron-sulfur (Fe-S) clusters, which are ubiquitous to many biological processes.
Collapse
Affiliation(s)
- Sunanda Margrett Williams
- Institute
of Structural and Molecular Biology, Birkbeck,
University of London, Malet Street, London WC1E
7HX, United Kingdom
| | - Dipankar Chatterji
- Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
2
|
Peng W, Yang X, Wang Y, Wang N, Li X, Chen H, Yuan F, Bei W. Mn uptake system affects the virulence of Streptococcus suis by mediating oxidative stress. Vet Microbiol 2022; 272:109518. [PMID: 35926476 DOI: 10.1016/j.vetmic.2022.109518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 07/26/2022] [Indexed: 10/16/2022]
Abstract
Manganese (Mn) is an important micronutrient that is not readily available to pathogens during infection. Hosts resist the invasion of pathogens through nutritional immunity and oxidative stress. To overcome this nutrient restriction, bacteria utilize high affinity transporters to compete with nutrient-binding proteins (e.g., calprotectin). Little is known about the role of Mn in the pathophysiology of Streptococcus suis. Here, we revealed that the tolerance of S. suis to calprotectin and oxidative stress was associated with Mn. Inactivation of Mn uptake system, TroABCD, in S. suis decreased the tolerance to calprotectin and oxidative stress. Furthermore, Mn uptake system mutant strains reduced capacity for bacterial cellular survival, and attenuated virulence in a mouse model. To explore the regulatory mechanism, we determined the transcriptional start site of troABCD using capping rapid amplification of cDNA ends. Furthermore, we revealed that TroR was a transcriptional regulatory repressor of troABCD. In the absence of troR, transcription levels of troA, troB, troC, and troD were not inhibited by low or high Mn levels, and intracellular Mn contents of mutant strains were higher than that of the wild-type strain. Finally, we used electrophoretic mobility shift assay to demonstrate that TroR bound the promoter region of troABCD. Collectively, this study revealed that Mn acquisition was essential for pathogenesis of S. suis and Mn uptake systems should be targets for the development of new antimicrobials.
Collapse
Affiliation(s)
- Wei Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Xia Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Yanna Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Ningning Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Xiaoyue Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China.
| | - Weicheng Bei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; Hubei Hongshan Laboratory, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China; Guangxi Yangxiang Co., Ltd, China.
| |
Collapse
|
3
|
PerR-Regulated Manganese Import Contributes to Oxidative Stress Defense in Streptococcus suis. Appl Environ Microbiol 2022; 88:e0008622. [PMID: 35465691 DOI: 10.1128/aem.00086-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Streptococcus suis has been increasingly recognized as a porcine zoonotic pathogen that threatens the health of both pigs and humans. Metal homeostasis plays a critical role in the antioxidative capability of bacteria, thus facilitating the escape of pathogenic species from the innate immunity systems of hosts. Here, we revealed that manganese increased the ability of S. suis to resist oxidative stress. RNA sequencing was used to identify potential candidate genes involved in the maintenance of intracellular manganese homeostasis. Four genes, termed troABCD, were identified by NCBI BLASTp analysis. The troA, troB, troC, and troD deletion mutant strains exhibited decreased intracellular manganese content and tolerance to H2O2 compared to the wild-type strain. Thus, troABCD were determined to be involved in manganese uptake and played an important role in H2O2 tolerance in S. suis. Furthermore, the inactivation of perR increased the survival of H2O2-pulsed S. suis 2.18-fold and elevated the intracellular manganese content. H2O2-pulsed S. suis and perR deletion mutants upregulated troABCD. This finding suggested that H2O2 released the suppression of troABCD by perR. In addition, an electrophoretic mobility shift assay (EMSA) showed that PerR at 500 ng binds to the troABCD promoter, indicating that troABCD were directly regulated by PerR. In conclusion, this study revealed that manganese increases tolerance to H2O2 by upregulating the expression of troABCD. Moreover, PerR-regulated Mn import in S. suis and increased the tolerance of S. suis to oxidative stress by regulating troABCD. IMPORTANCE During infection, it is extremely important for bacteria to defend against oxidative stress. While manganese plays an important role in this process, its role is unclear in S. suis. Here, we demonstrated that manganese increased S. suis tolerance to oxidative stress. Four manganese ABC transporter genes, troABCD, were identified. Oxidative stress increased the content of manganese in the cell. Furthermore, PerR increased the tolerance to oxidative stress of S. suis by regulating troABCD. Manganese played an important role in bacterial defense against oxidative stress. These findings provide novel insight into the mechanism by which S. suis resists oxidative stress and approaches to inhibit bacterial infection by limiting manganese intake.
Collapse
|
4
|
Abstract
The DNA-binding protein from starved cells, Dps, is a universally conserved prokaryotic ferritin that, in many species, also binds DNA. Dps homologs have been identified in the vast majority of bacterial species and several archaea. Dps also may play a role in the global regulation of gene expression, likely through chromatin reorganization. Dps has been shown to use both its ferritin and DNA-binding functions to respond to a variety of environmental pressures, including oxidative stress. One mechanism that allows Dps to achieve this is through a global nucleoid restructuring event during stationary phase, resulting in a compact, hexacrystalline nucleoprotein complex called the biocrystal that occludes damaging agents from DNA. Due to its small size, hollow spherical structure, and high stability, Dps is being developed for applications in biotechnology.
Collapse
|
5
|
|
6
|
Dps-DNA interaction in Marinobacter hydrocarbonoclasticus protein: effect of a single-charge alteration. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 50:513-521. [PMID: 33900431 DOI: 10.1007/s00249-021-01538-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 12/15/2022]
Abstract
DNA-binding proteins from starved cells (Dps) are members of the ferritin family of proteins found in prokaryotes, with hollow rounded cube-like structures, composed of 12 equal subunits. These protein nanocages are bifunctional enzymes that protect the cell from the harmful reaction of iron and peroxide (Fenton reaction), thus preventing DNA damage by oxidative stress. Ferrous ions are oxidized at specific iron-binding sites in the presence of the oxidant and stored in its cavity that can accommodate up to ca. 500 iron atoms. DNA-binding properties of Dps are associated with the N-terminal, positive charge rich, extensions that can promote DNA binding and condensation, apparently by a cooperative binding mechanism. Here, we describe the binding and protection activities of Marinobacter hydrocarbonoclasticus Dps using Electrophoretic Mobility Shift Essays (EMSA), and synchrotron radiation circular dichroism (SRCD) spectroscopy. While no DNA condensation was observed in the tested conditions, it was possible to determine a Dps-DNA complex formation with an apparent dissociation constant of 6.0 ± 1.0 µM and a Hill coefficient of 1.2 ± 0.1. This interaction is suppressed by the inclusion of a single negative charge in the N-terminal region by point mutation. In Dps proteins containing a ferric mineral core (above 96 Fe/protein), DNA binding was impaired. SRCD data clearly showed that no significant modification existed either in secondary structure or protein stability of WT, Q14E variant and core containing proteins. It was, however, interesting to note that, in our experimental conditions, thermal denaturation induced protein aggregation that caused artifacts in thermal denaturation curves, which were dependent on radiation flux and vertical arrangement of the CD cell.
Collapse
|
7
|
Bradley JM, Svistunenko DA, Wilson MT, Hemmings AM, Moore GR, Le Brun NE. Bacterial iron detoxification at the molecular level. J Biol Chem 2021; 295:17602-17623. [PMID: 33454001 PMCID: PMC7762939 DOI: 10.1074/jbc.rev120.007746] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 10/07/2020] [Indexed: 01/18/2023] Open
Abstract
Iron is an essential micronutrient, and, in the case of bacteria, its availability is commonly a growth-limiting factor. However, correct functioning of cells requires that the labile pool of chelatable "free" iron be tightly regulated. Correct metalation of proteins requiring iron as a cofactor demands that such a readily accessible source of iron exist, but overaccumulation results in an oxidative burden that, if unchecked, would lead to cell death. The toxicity of iron stems from its potential to catalyze formation of reactive oxygen species that, in addition to causing damage to biological molecules, can also lead to the formation of reactive nitrogen species. To avoid iron-mediated oxidative stress, bacteria utilize iron-dependent global regulators to sense the iron status of the cell and regulate the expression of proteins involved in the acquisition, storage, and efflux of iron accordingly. Here, we survey the current understanding of the structure and mechanism of the important members of each of these classes of protein. Diversity in the details of iron homeostasis mechanisms reflect the differing nutritional stresses resulting from the wide variety of ecological niches that bacteria inhabit. However, in this review, we seek to highlight the similarities of iron homeostasis between different bacteria, while acknowledging important variations. In this way, we hope to illustrate how bacteria have evolved common approaches to overcome the dual problems of the insolubility and potential toxicity of iron.
Collapse
Affiliation(s)
- Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
| | | | - Michael T Wilson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Andrew M Hemmings
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom; Centre for Molecular and Structural Biochemistry, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Geoffrey R Moore
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
| |
Collapse
|
8
|
Minato T, Teramoto T, Kakuta Y, Ogo S, Yoon KS. Biochemical and structural characterization of a thermostable Dps protein with His-type ferroxidase centers and outer metal-binding sites. FEBS Open Bio 2020; 10:1219-1229. [PMID: 32170832 PMCID: PMC7327923 DOI: 10.1002/2211-5463.12837] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/06/2020] [Accepted: 03/11/2020] [Indexed: 12/16/2022] Open
Abstract
The DNA‐binding protein from starved cells (Dps) is found in a wide range of microorganisms, and it has been well characterized. However, little is known about Dps proteins from nonheterocystous filamentous cyanobacteria. In this study, a Dps protein from the thermophilic nonheterocystous filamentous cyanobacterium Thermoleptolyngbya sp. O‐77 (TlDps1) was purified and characterized. PAGE and CD analyses of TlDps1 demonstrated that it had higher thermostability than previously reported Dps proteins. X‐ray crystallographic analysis revealed that TlDps1 possessed His‐type ferroxidase centers within the cavity and unique metal‐binding sites located on the surface of the protein, which presumably contributed to its exceedingly high thermostability.
Collapse
Affiliation(s)
- Takuo Minato
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka, Japan
| | - Takamasa Teramoto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Yoshimitsu Kakuta
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.,Laboratory of Structural Biology, Graduate School of System Life Sciences, Kyushu University, Fukuoka, Japan
| | - Seiji Ogo
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka, Japan.,Center for Small Molecule Energy, Kyushu University, Fukuoka, Japan
| | - Ki-Seok Yoon
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka, Japan.,Center for Small Molecule Energy, Kyushu University, Fukuoka, Japan
| |
Collapse
|