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Sachla AJ, Soni V, Piñeros M, Luo Y, Im JJ, Rhee KY, Helmann JD. The Bacillus subtilis yqgC-sodA operon protects magnesium-dependent enzymes by supporting manganese efflux. J Bacteriol 2024; 206:e0005224. [PMID: 38819154 DOI: 10.1128/jb.00052-24] [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: 02/13/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024] Open
Abstract
Microbes encounter a myriad of stresses during their life cycle. Dysregulation of metal ion homeostasis is increasingly recognized as a key factor in host-microbe interactions. Bacterial metal ion homeostasis is tightly regulated by dedicated metalloregulators that control uptake, sequestration, trafficking, and efflux. Here, we demonstrate that deletion of the Bacillus subtilis yqgC-sodA (YS) complex operon, but not deletion of the individual genes, causes hypersensitivity to manganese (Mn). YqgC is an integral membrane protein of unknown function, and SodA is a Mn-dependent superoxide dismutase (MnSOD). The YS strain has reduced expression of two Mn efflux proteins, MneP and MneS, consistent with the observed Mn sensitivity. The YS strain accumulated high levels of Mn, had increased reactive radical species (RRS), and had broad metabolic alterations that can be partially explained by the inhibition of Mg-dependent enzymes. Although the YS operon deletion strain and an efflux-deficient mneP mneS double mutant both accumulate Mn and have similar metabolic perturbations, they also display phenotypic differences. Several mutations that suppressed Mn intoxication of the mneP mneS efflux mutant did not benefit the YS mutant. Further, Mn intoxication in the YS mutant, but not the mneP mneS strain, was alleviated by expression of Mg-dependent, chorismate-utilizing enzymes of the menaquinone, siderophore, and tryptophan (MST) family. Therefore, despite their phenotypic similarities, the Mn sensitivity in the mneP mneS and the YS deletion mutants results from distinct enzymatic vulnerabilities.IMPORTANCEBacteria require multiple trace metal ions for survival. Metal homeostasis relies on the tightly regulated expression of metal uptake, storage, and efflux proteins. Metal intoxication occurs when metal homeostasis is perturbed and often results from enzyme mis-metalation. In Bacillus subtilis, Mn-dependent superoxide dismutase (MnSOD) is the most abundant Mn-containing protein and is important for oxidative stress resistance. Here, we report novel roles for MnSOD and a co-regulated membrane protein, YqgC, in Mn homeostasis. Loss of both MnSOD and YqgC (but not the individual proteins) prevents the efficient expression of Mn efflux proteins and leads to a large-scale perturbation of the metabolome due to inhibition of Mg-dependent enzymes, including key chorismate-utilizing MST (menaquinone, siderophore, and tryptophan) family enzymes.
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Affiliation(s)
- Ankita J Sachla
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Vijay Soni
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - Miguel Piñeros
- School of Integrative Plant Sciences, Plant Biology Section, Cornell University, Ithaca, New York, USA
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Ithaca, New York, USA
| | - Yuanchan Luo
- Department of Microbiology, Cornell University, Ithaca, New York, USA
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Janice J Im
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Kyu Y Rhee
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, New York, USA
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Mohite SV, Sharma KK. Gut microbial metalloproteins and its role in xenobiotics degradation and ROS scavenging. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 141:495-538. [PMID: 38960484 DOI: 10.1016/bs.apcsb.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The gut microbial metalloenzymes play an important role in maintaining the balance between gut microbial ecosystem, human physiologically processes and immune system. The metals coordinated into active site contribute in various detoxification and defense strategies to avoid unfavourable environment and ensure bacterial survival in human gut. Metallo-β-lactamase is a potent degrader of antibiotics present in periplasmic space of both commensals and pathogenic bacteria. The resistance to anti-microbial agents developed in this enzyme is one of the global threats for human health. The organophosphorus eliminator, organophosphorus hydrolases have evolved over a course of time to hydrolyze toxic organophosphorus compounds and decrease its effect on human health. Further, the redox stress responders namely superoxide dismutase and catalase are key metalloenzymes in reducing both endogenous and exogenous oxidative stress. They hold a great importance for pathogens as they contribute in pathogenesis in human gut along with reduction of oxidative stress. The in-silico study on these enzymes reveals the importance of point mutation for the evolution of these enzymes in order to enhance their enzyme activity and stability. Various mutation studies were conducted to investigate the catalytic activity of these enzymes. By using the "directed evolution" method, the enzymes involved in detoxification and defense system can be engineered to produce new variants with enhance catalytic features, which may be used to predict the severity due to multi-drug resistance and degradation pattern of organophosphorus compounds in human gut.
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Affiliation(s)
- Shreya Vishwas Mohite
- Laboratory of Enzymology and Gut Microbiology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Krishna Kant Sharma
- Laboratory of Enzymology and Gut Microbiology, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India.
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Tripathi A, Dubey KD. The mechanistic insights into different aspects of promiscuity in metalloenzymes. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 141:23-66. [PMID: 38960476 DOI: 10.1016/bs.apcsb.2023.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Enzymes are nature's ultimate machinery to catalyze complex reactions. Though enzymes are evolved to catalyze specific reactions, they also show significant promiscuity in reactions and substrate selection. Metalloenzymes contain a metal ion or metal cofactor in their active site, which is crucial in their catalytic activity. Depending on the metal and its coordination environment, the metal ion or cofactor may function as a Lewis acid or base and a redox center and thus can catalyze a plethora of natural reactions. In fact, the versatility in the oxidation state of the metal ions provides metalloenzymes with a high level of catalytic adaptability and promiscuity. In this chapter, we discuss different aspects of promiscuity in metalloenzymes by using several recent experimental and theoretical works as case studies. We start our discussion by introducing the concept of promiscuity and then we delve into the mechanistic insight into promiscuity at the molecular level.
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Affiliation(s)
- Ankita Tripathi
- Department of Chemistry, School of Natural Science, Shiv Nadar Institution of Eminence, Greater Noida, Uttar Pradesh, India
| | - Kshatresh Dutta Dubey
- Department of Chemistry, School of Natural Science, Shiv Nadar Institution of Eminence, Greater Noida, Uttar Pradesh, India.
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Kwiatos N, Waldron KJ. In a state of flux: new insight into the transport processes that maintain bacterial metal homeostasis. J Bacteriol 2024; 206:e0014624. [PMID: 38712925 PMCID: PMC11112988 DOI: 10.1128/jb.00146-24] [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] [Indexed: 05/08/2024] Open
Abstract
A new study by Nies et al. (J Bacteriol 206:e00080-24, 2024, https://doi.org/10.1128/jb.00080-24) provides a rich, quantitative data set of zinc accumulation by cells of Cupriavidus metallidurans, including of mutant bacterial strains lacking import or efflux genes, and comparison of zinc accumulation by cells previously starved of metal with those of zinc-replete cells. The data surprisingly demonstrate the concomitant activity of both active metal import and metal efflux systems. They present a flow equilibrium model to describe zinc homeostasis in bacteria.
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Affiliation(s)
- Natalia Kwiatos
- Laboratory of Metalloprotein Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Kevin J. Waldron
- Laboratory of Metalloprotein Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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Rohaun SK, Sethu R, Imlay JA. Microbes vary strategically in their metalation of mononuclear enzymes. Proc Natl Acad Sci U S A 2024; 121:e2401738121. [PMID: 38743623 PMCID: PMC11127058 DOI: 10.1073/pnas.2401738121] [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: 01/25/2024] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Studies have determined that nonredox enzymes that are cofactored with Fe(II) are the most oxidant-sensitive targets inside Escherichia coli. These enzymes use Fe(II) cofactors to bind and activate substrates. Because of their solvent exposure, the metal can be accessed and oxidized by reactive oxygen species, thereby inactivating the enzyme. Because these enzymes participate in key physiological processes, the consequences of stress can be severe. Accordingly, when E. coli senses elevated levels of H2O2, it induces both a miniferritin and a manganese importer, enabling the replacement of the iron atom in these enzymes with manganese. Manganese does not react with H2O2 and thereby preserves enzyme activity. In this study, we examined several diverse microbes to identify the metal that they customarily integrate into ribulose-5-phosphate 3-epimerase, a representative of this enzyme family. The anaerobe Bacteroides thetaiotaomicron, like E. coli, uses iron. In contrast, Bacillus subtilis and Lactococcus lactis use manganese, and Saccharomyces cerevisiae uses zinc. The latter organisms are therefore well suited to the oxidizing environments in which they dwell. Similar results were obtained with peptide deformylase, another essential enzyme of the mononuclear class. Strikingly, heterologous expression experiments show that it is the metal pool within the organism, rather than features of the protein itself, that determine which metal is incorporated. Further, regardless of the source organism, each enzyme exhibits highest turnover with iron and lowest turnover with zinc. We infer that the intrinsic catalytic properties of the metal cannot easily be retuned by evolution of the polypeptide.
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Affiliation(s)
| | | | - James A. Imlay
- Department of Microbiology, University of Illinois, Urbana, IL61801
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Sachla AJ, Soni V, Piñeros M, Luo Y, Im JJ, Rhee KY, Helmann JD. The Bacillus subtilis yqgC-sodA operon protects magnesium-dependent enzymes by supporting manganese efflux. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580342. [PMID: 38405924 PMCID: PMC10888875 DOI: 10.1101/2024.02.14.580342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Microbes encounter a myriad of stresses during their life cycle. Dysregulation of metal ion homeostasis is increasingly recognized as a key factor in host-microbe interactions. Bacterial metal ion homeostasis is tightly regulated by dedicated metalloregulators that control uptake, sequestration, trafficking, and efflux. Here, we demonstrate that deletion of the Bacillus subtilis yqgC-sodA (YS) complex operon, but not deletion of the individual genes, causes hypersensitivity to manganese (Mn). YqgC is an integral membrane protein of unknown function and SodA is a Mn-dependent superoxide dismutase (MnSOD). The YS strain has reduced expression of two Mn efflux proteins, MneP and MneS, consistent with the observed Mn sensitivity. The YS strain accumulated high levels of Mn, had increased reactive radical species (RRS), and had broad metabolic alterations that can be partially explained by the inhibition of Mg-dependent enzymes. Although the YS operon deletion strain and an efflux-deficient mneP mneS double mutant both accumulate Mn and have similar metabolic perturbations they also display phenotypic differences. Several mutations that suppressed Mn intoxication of the mneP mneS efflux mutant did not benefit the YS mutant. Further, Mn intoxication in the YS mutant, but not the mneP mneS strain, was alleviated by expression of Mg-dependent, chorismate-utilizing enzymes of the menaquinone, siderophore, and tryptophan (MST) family. Therefore, despite their phenotypic similarities, the Mn sensitivity in the mneP mneS and the yqgC-sodA deletion mutants results from distinct enzymatic vulnerabilities.
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Affiliation(s)
- Ankita J. Sachla
- Cornell University, Department of Microbiology, Ithaca, NY, 14853-8101, USA
| | - Vijay Soni
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Miguel Piñeros
- School of Integrative Plant Sciences, Plant Biology Section, Cornell University, Ithaca, NY 14853, USA
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Ithaca, NY 14853, USA
| | - Yuanchan Luo
- Cornell University, Department of Microbiology, Ithaca, NY, 14853-8101, USA
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Janice J. Im
- Cornell University, Department of Microbiology, Ithaca, NY, 14853-8101, USA
| | - Kyu Y. Rhee
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - John D. Helmann
- Cornell University, Department of Microbiology, Ithaca, NY, 14853-8101, USA
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Liu C, Powell MM, Rao G, Britt RD, Rittle J. Bioinformatic Discovery of a Cambialistic Monooxygenase. J Am Chem Soc 2024; 146:1783-1788. [PMID: 38198693 PMCID: PMC10811679 DOI: 10.1021/jacs.3c12131] [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: 10/30/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 01/12/2024]
Abstract
Dinuclear monooxygenases mediate challenging C-H bond oxidation reactions throughout nature. Many of these enzymes are presumed to exclusively utilize diiron cofactors. Herein we report the bioinformatic discovery of an orphan dinuclear monooxygenase that preferentially utilizes a heterobimetallic manganese-iron (Mn/Fe) cofactor to mediate an O2-dependent C-H bond hydroxylation reaction. Unlike the structurally similar Mn/Fe-dependent monooxygenase AibH2, the diiron form of this enzyme (SfbO) exhibits a nascent enzymatic activity. This behavior raises the possibility that many other dinuclear monooxygenases may be endowed with the capacity to harness cofactors with a variable metal content.
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Affiliation(s)
- Chang Liu
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California 94720, United States
| | - Magan M. Powell
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California 94720, United States
| | - Guodong Rao
- Department
of Chemistry, University of California,
Davis, Davis, California 95616, United States
| | - R. David Britt
- Department
of Chemistry, University of California,
Davis, Davis, California 95616, United States
| | - Jonathan Rittle
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California 94720, United States
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