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Brunson DN, Lemos JA. Heme utilization by the enterococci. FEMS MICROBES 2024; 5:xtae019. [PMID: 39070772 PMCID: PMC11282960 DOI: 10.1093/femsmc/xtae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/02/2024] [Accepted: 07/01/2024] [Indexed: 07/30/2024] Open
Abstract
Heme consists of a tetrapyrrole ring ligating an iron ion and has important roles in biological systems. While well-known as the oxygen-binding molecule within hemoglobin of mammals, heme is also cofactor for several enzymes and a major iron source for bacteria within the host. The enterococci are a diverse group of Gram-positive bacteria that exist primarily within the gastrointestinal tract of animals. However, some species within this genus can transform into formidable opportunistic pathogens, largely owing to their extraordinary adaptability to hostile environments. Although enterococci cannot synthesize heme nor depend on heme to grow, several species within the genus encode proteins that utilize heme as a cofactor, which appears to increase their fitness and ability to thrive in challenging environments. This includes more efficient energy generation via aerobic respiration and protection from reactive oxygen species. Here, we review the significance of heme to enterococci, primarily the major human pathogen Enterococcus faecalis, use bioinformatics to assess the prevalence of hemoproteins throughout the genus, and highlight recent studies that underscore the central role of the heme-E. faecalis relationship in host-pathogen dynamics and interspecies bacterial interactions.
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Affiliation(s)
- Debra N Brunson
- Department of Oral Biology, University of Florida College of Dentistry, 1395 Center Drive, Gainesville, FL 32610, United States
| | - José A Lemos
- Department of Oral Biology, University of Florida College of Dentistry, 1395 Center Drive, Gainesville, FL 32610, United States
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Wan Q, Zhai S, Chen M, Xu M, Guo S. Comparative phenotype and transcriptome analysis revealed the role of ferric uptake regulator (Fur) in the virulence of Vibrio harveyi isolated from diseased American eel (Anguilla rostrata). JOURNAL OF FISH DISEASES 2024; 47:e13931. [PMID: 38373044 DOI: 10.1111/jfd.13931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/20/2024]
Abstract
Vibrio harveyi is commonly found in salt and brackish water and is recognized as a serious bacterial pathogen in aquaculture worldwide. In this study, we cloned the ferric uptake regulator (fur) gene from V. harveyi wild-type strain HA_1, which was isolated from diseased American eels (Anguilla rostrata) and has a length of 450 bp, encoding 149 amino acids. Then, a mutant strain, HA_1-Δfur, was constructed through homologous recombination of a suicide plasmid (pCVD442). The HA_1-Δfur mutant exhibited weaker biofilm formation and swarming motility, and 18-fold decrease (5.5%) in virulence to the American eels; compared to the wild-type strain, the mutant strain showed time and diameter differences in growth and haemolysis, respectively. Additionally, the adhesion ability of the mutant strain was significantly decreased. Moreover, there were 15 different biochemical indicators observed between the two strains. Transcriptome analysis revealed that 875 genes were differentially expressed in the Δfur mutant, with 385 up-regulated and 490 down-regulated DEGs. GO and KEGG enrichment analysis revealed that, compared to the wild-type strain, the type II and type VI secretion systems (T2SS and T6SS), amino acid synthesis and transport and energy metabolism pathways were significantly down-regulated, but the ABC transporters and biosynthesis of siderophore group non-ribosomal peptides pathways were up-regulated in the Δfur strain. The qRT-PCR results further confirmed that DEGs responsible for amino acid transport and energy metabolism were positively regulated, but DEGs involved in iron acquisition were negatively regulated in the Δfur strain. These findings suggest that the virulence of the Δfur strain was significantly decreased, which is closely related to phenotype changing and gene transcript regulation.
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Affiliation(s)
- Qijuan Wan
- Fisheries College of Jimei University/Engineering Research Center of the Modern Industry Technology for Eel, Ministry of Education of PRC, Xiamen, China
- State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China
| | - Shaowei Zhai
- Fisheries College of Jimei University/Engineering Research Center of the Modern Industry Technology for Eel, Ministry of Education of PRC, Xiamen, China
- State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China
| | - Minxia Chen
- Fisheries College of Jimei University/Engineering Research Center of the Modern Industry Technology for Eel, Ministry of Education of PRC, Xiamen, China
- State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China
| | - Ming Xu
- Fisheries College of Jimei University/Engineering Research Center of the Modern Industry Technology for Eel, Ministry of Education of PRC, Xiamen, China
- State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China
| | - Songlin Guo
- Fisheries College of Jimei University/Engineering Research Center of the Modern Industry Technology for Eel, Ministry of Education of PRC, Xiamen, China
- State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University, Xiamen, China
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Brimberry M, Corrigan P, Silakov A, Lanzilotta WN. Evidence for Porphyrin-Mediated Electron Transfer in the Radical SAM Enzyme HutW. Biochemistry 2023; 62:1191-1196. [PMID: 36877586 PMCID: PMC10035031 DOI: 10.1021/acs.biochem.2c00474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Bacteria that infect the human gut must compete for essential nutrients, including iron, under a variety of different metabolic conditions. Several enteric pathogens, including Vibrio cholerae and Escherichia coli O157:H7, have evolved mechanisms to obtain iron from heme in an anaerobic environment. Our laboratory has demonstrated that a radical S-adenosylmethionine (SAM) methyltransferase is responsible for the opening of the heme porphyrin ring and release of iron under anaerobic conditions. Furthermore, the enzyme in V. cholerae, HutW, has recently been shown to accept electrons from NADPH directly when SAM is utilized to initiate the reaction. However, how NADPH, a hydride donor, catalyzes the single electron reduction of a [4Fe-4S] cluster, and/or subsequent electron/proton transfer reactions, was not addressed. In this work, we provide evidence that the substrate, in this case, heme, facilitates electron transfer from NADPH to the [4Fe-4S] cluster. This study uncovers a new electron transfer pathway adopted by radical SAM enzymes and further expands our understanding of these enzymes in bacterial pathogens.
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Affiliation(s)
- Marley Brimberry
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, United States
| | - Patrick Corrigan
- Department of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
| | - Alexey Silakov
- Department of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States
| | - William N Lanzilotta
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602, United States
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Murdoch CC, Skaar EP. Nutritional immunity: the battle for nutrient metals at the host-pathogen interface. Nat Rev Microbiol 2022; 20:657-670. [PMID: 35641670 PMCID: PMC9153222 DOI: 10.1038/s41579-022-00745-6] [Citation(s) in RCA: 152] [Impact Index Per Article: 76.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2022] [Indexed: 12/21/2022]
Abstract
Trace metals are essential micronutrients required for survival across all kingdoms of life. From bacteria to animals, metals have critical roles as both structural and catalytic cofactors for an estimated third of the proteome, representing a major contributor to the maintenance of cellular homeostasis. The reactivity of metal ions engenders them with the ability to promote enzyme catalysis and stabilize reaction intermediates. However, these properties render metals toxic at high concentrations and, therefore, metal levels must be tightly regulated. Having evolved in close association with bacteria, vertebrate hosts have developed numerous strategies of metal limitation and intoxication that prevent bacterial proliferation, a process termed nutritional immunity. In turn, bacterial pathogens have evolved adaptive mechanisms to survive in conditions of metal depletion or excess. In this Review, we discuss mechanisms by which nutrient metals shape the interactions between bacterial pathogens and animal hosts. We explore the cell-specific and tissue-specific roles of distinct trace metals in shaping bacterial infections, as well as implications for future research and new therapeutic development.
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Affiliation(s)
- Caitlin C Murdoch
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN, USA.
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Mathew LG, Brimberry M, Lanzilotta WN. Class C Radical SAM Methyltransferases Involved in Anaerobic Heme Degradation. ACS BIO & MED CHEM AU 2022; 2:120-124. [PMID: 37101744 PMCID: PMC10114669 DOI: 10.1021/acsbiomedchemau.1c00047] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Class C radical SAM methyltransferases catalyze a diverse array of difficult chemical transformations in the biosynthesis of a range of compounds of biomedical importance. Phylogenetic analysis suggests that all of these enzymes are related to "CpdH" (formerly "HemN") and "HemW", proteins with essential roles in anaerobic heme biosynthesis and heme transport, respectively. These functions are essential to anaerobic metabolism in Escherichia coli. Interestingly, evolution has come full circle, and the divergence of this protein sequence/fold has resulted in the class C radical SAM methyltransferases. Several pathogenic organisms have further adapted this fold to catalyze the anaerobic degradation of heme. In this review, we summarize what is known about the mechanism of anaerobic heme degradation and the evolutionary implications.
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Affiliation(s)
- Jinduo Cheng
- Department of Chemistry Fudan University Shanghai 200433 China
| | - Wei Ding
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology Shanghai Jiao Tong University Shanghai 200240 China
| | - Qi Zhang
- Department of Chemistry Fudan University Shanghai 200433 China
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Cheng J, Liu WQ, Zhu X, Zhang Q. Functional Diversity of HemN-like Proteins. ACS BIO & MED CHEM AU 2022; 2:109-119. [PMID: 37101745 PMCID: PMC10114718 DOI: 10.1021/acsbiomedchemau.1c00058] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
HemN is a radical S-adenosylmethionine (SAM) enzyme that catalyzes the anaerobic oxidative decarboxylation of coproporphyrinogen III to produce protoporphyrinogen IX, a key intermediate in heme biosynthesis. Proteins homologous to HemN (HemN-like proteins) are widespread in both prokaryotes and eukaryotes. Although these proteins are in most cases annotated as anaerobic coproporphyrinogen III oxidases (CPOs) in the public database, many of them are actually not CPOs but have diverse functions such as methyltransferases, cyclopropanases, heme chaperones, to name a few. This Perspective discusses the recent advances in the understanding of HemN-like proteins, and particular focus is placed on the diverse chemistries and functions of this growing protein family.
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Affiliation(s)
- Jinduo Cheng
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Wan-Qiu Liu
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Xiaoyu Zhu
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Qi Zhang
- Department of Chemistry, Fudan University, Shanghai, 200433, China
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Brimberry MA, Mathew L, Lanzilotta W. Making and breaking carbon-carbon bonds in class C radical SAM methyltransferases. J Inorg Biochem 2022; 226:111636. [PMID: 34717253 PMCID: PMC8667262 DOI: 10.1016/j.jinorgbio.2021.111636] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/07/2021] [Accepted: 10/12/2021] [Indexed: 01/03/2023]
Abstract
Radical S-adenosylmethionine (SAM) enzymes utilize a [4Fe-4S]1+ cluster and S-(5'-adenosyl)-L-methionine, (SAM), to generate a highly reactive radical and catalyze what is arguably the most diverse set of chemical reactions for any known enzyme family. At the heart of radical SAM catalysis is a highly reactive 5'-deoxyadenosyl radical intermediate (5'-dAdo●) generated through reductive cleavage of SAM or nucleophilic attack of the unique iron of the [4Fe-4S]+ cluster on the 5' C atom of SAM. Spectroscopic studies reveal the 5'-dAdo● is transiently captured in an FeC bond (Ω species). In the presence of substrate, homolytic scission of this metal‑carbon bond regenerates the 5'-dAdo● for catalytic hydrogen atom abstraction. While reminiscent of the adenosylcobalamin mechanism, radical SAM enzymes appear to encompass greater catalytic diversity. In this review we discuss recent developments for radical SAM enzymes involved in unique chemical rearrangements, specifically regarding class C radical SAM methyltransferases. Illuminating this class of radical SAM enzymes is especially significant as many enzymes have been shown to play critical roles in pathogenesis and the synthesis of novel antimicrobial compounds.
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Affiliation(s)
- Marley A. Brimberry
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies,,Department of Chemistry University of Georgia, Athens GA 30602
| | - Liju Mathew
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies,,Department of Chemistry University of Georgia, Athens GA 30602
| | - William Lanzilotta
- Department of Biochemistry and Molecular Biology & Center for Metalloenzyme Studies,,Department of Chemistry University of Georgia, Athens GA 30602.,To whom correspondence should be addressed. Phone, (706) 542-1324; fax, (706) 542-1738;
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