1
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Paoli-Lombardo R, Primas N, Vanelle P. DprE1 and Ddn as promising therapeutic targets in the development of novel anti-tuberculosis nitroaromatic drugs. Eur J Med Chem 2024; 274:116559. [PMID: 38850856 DOI: 10.1016/j.ejmech.2024.116559] [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: 02/21/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/10/2024]
Abstract
Tuberculosis remains the second deadliest infectious disease in humans and a public health threat due to the emergence of multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) strains. Therefore, it is urgent to identify new anti-tuberculosis treatments and novel therapeutic targets to prevent the emergence of resistance. In recent years, the study of anti-tuberculosis properties of nitroaromatic compounds has led to the identification of two novel biological targets, the deazaflavin (F420)-dependent nitroreductase Ddn and the decaprenylphosphoryl-β-d-ribose 2'-epimerase DprE1. This review aims to show why Ddn and DprE1 are promising therapeutic targets and highlight nitroaromatic compounds interest in developing new anti-tuberculosis treatments active against MDR-TB and XDR-TB. Despite renewed interest in the development of new anti-tuberculosis nitroaromatic compounds, pharmaceutical companies often exclude nitro-containing molecules from their drug discovery programs because of their toxic and mutagenic potential. This exclusion results in missed opportunities to identify new nitroaromatic compounds and promising therapeutic targets.
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Affiliation(s)
- Romain Paoli-Lombardo
- Aix Marseille Univ, CNRS, ICR UMR 7273, Laboratoire de Pharmaco-Chimie Radicalaire, 13385, Marseille, France; AP-HM, Service Central de la Qualité et de l'Information Pharmaceutiques, 13005, Marseille, France
| | - Nicolas Primas
- Aix Marseille Univ, CNRS, ICR UMR 7273, Laboratoire de Pharmaco-Chimie Radicalaire, 13385, Marseille, France; AP-HM, Service Central de la Qualité et de l'Information Pharmaceutiques, 13005, Marseille, France
| | - Patrice Vanelle
- Aix Marseille Univ, CNRS, ICR UMR 7273, Laboratoire de Pharmaco-Chimie Radicalaire, 13385, Marseille, France; AP-HM, Service Central de la Qualité et de l'Information Pharmaceutiques, 13005, Marseille, France.
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2
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Bashiri G. F 420-dependent transformations in biosynthesis of secondary metabolites. Curr Opin Chem Biol 2024; 80:102468. [PMID: 38776765 DOI: 10.1016/j.cbpa.2024.102468] [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: 04/07/2024] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 05/25/2024]
Abstract
Cofactor F420 has been historically known as the "methanogenic redox cofactor". It is now recognised that F420 has essential roles in the primary and secondary metabolism of archaea and bacteria. Recent discoveries highlight the role of F420 as a redox cofactor in the biosynthesis of various natural products, including ribosomally synthesised and post-translationally modified peptides, and a new class of nicotinamide adenine dinucleotide-based secondary metabolites. With the vast availability of (meta)genomic data, the identification of uncharacterised F420-dependent enzymes offers the potential for discovering novel secondary metabolites, presenting valuable prospects for clinical and biotechnological applications.
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Affiliation(s)
- Ghader Bashiri
- Laboratory of Microbial Biochemistry and Biotechnology, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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3
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Grosjean N, Yee EF, Kumaran D, Chopra K, Abernathy M, Biswas S, Byrnes J, Kreitler DF, Cheng JF, Ghosh A, Almo SC, Iwai M, Niyogi KK, Pakrasi HB, Sarangi R, van Dam H, Yang L, Blaby IK, Blaby-Haas CE. A hemoprotein with a zinc-mirror heme site ties heme availability to carbon metabolism in cyanobacteria. Nat Commun 2024; 15:3167. [PMID: 38609367 PMCID: PMC11014987 DOI: 10.1038/s41467-024-47486-z] [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: 05/02/2023] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
Heme has a critical role in the chemical framework of the cell as an essential protein cofactor and signaling molecule that controls diverse processes and molecular interactions. Using a phylogenomics-based approach and complementary structural techniques, we identify a family of dimeric hemoproteins comprising a domain of unknown function DUF2470. The heme iron is axially coordinated by two zinc-bound histidine residues, forming a distinct two-fold symmetric zinc-histidine-iron-histidine-zinc site. Together with structure-guided in vitro and in vivo experiments, we further demonstrate the existence of a functional link between heme binding by Dri1 (Domain related to iron 1, formerly ssr1698) and post-translational regulation of succinate dehydrogenase in the cyanobacterium Synechocystis, suggesting an iron-dependent regulatory link between photosynthesis and respiration. Given the ubiquity of proteins containing homologous domains and connections to heme metabolism across eukaryotes and prokaryotes, we propose that DRI (Domain Related to Iron; formerly DUF2470) functions at the molecular level as a heme-dependent regulatory domain.
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Affiliation(s)
- Nicolas Grosjean
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Estella F Yee
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Desigan Kumaran
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kriti Chopra
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY, USA
| | - Macon Abernathy
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Sandeep Biswas
- Department of Biology, Washington University, St. Louis, MO, USA
| | - James Byrnes
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Dale F Kreitler
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Jan-Fang Cheng
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Agnidipta Ghosh
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Steven C Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Masakazu Iwai
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
| | | | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Hubertus van Dam
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Lin Yang
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Ian K Blaby
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Crysten E Blaby-Haas
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA.
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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4
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Yang G, Wijma HJ, Rozeboom HJ, Mascotti ML, Fraaije MW. Identification and characterization of archaeal and bacterial F 420 -dependent thioredoxin reductases. FEBS J 2023; 290:4777-4791. [PMID: 37403630 DOI: 10.1111/febs.16896] [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: 03/04/2023] [Revised: 06/19/2023] [Accepted: 07/04/2023] [Indexed: 07/06/2023]
Abstract
The thioredoxin pathway is an antioxidant system present in most organisms. Electrons flow from a thioredoxin reductase to thioredoxin at the expense of a specific electron donor. Most known thioredoxin reductases rely on NADPH as a reducing cofactor. Yet, in 2016, a new type of thioredoxin reductase was discovered in Archaea which utilize instead a reduced deazaflavin cofactor (F420 H2 ). For this reason, the respective enzyme was named deazaflavin-dependent flavin-containing thioredoxin reductase (DFTR). To have a broader understanding of the biochemistry of DFTRs, we identified and characterized two other archaeal representatives. A detailed kinetic study, which included pre-steady state kinetic analyses, revealed that these two DFTRs are highly specific for F420 H2 while displaying marginal activity with NADPH. Nevertheless, they share mechanistic features with the canonical thioredoxin reductases that are dependent on NADPH (NTRs). A detailed structural analysis led to the identification of two key residues that tune cofactor specificity of DFTRs. This allowed us to propose a DFTR-specific sequence motif that enabled for the first time the identification and experimental characterization of a bacterial DFTR.
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Affiliation(s)
- Guang Yang
- Molecular Enzymology Group, University of Groningen, The Netherlands
| | - Hein J Wijma
- Molecular Enzymology Group, University of Groningen, The Netherlands
| | | | - Maria Laura Mascotti
- Molecular Enzymology Group, University of Groningen, The Netherlands
- IMIBIO-SL CONICET, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Argentina
| | - Marco W Fraaije
- Molecular Enzymology Group, University of Groningen, The Netherlands
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5
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Eke IE, Williams JT, Haiderer ER, Albrecht VJ, Murdoch HM, Abdalla BJ, Abramovitch RB. Discovery and characterization of antimycobacterial nitro-containing compounds with distinct mechanisms of action and in vivo efficacy. Antimicrob Agents Chemother 2023; 67:e0047423. [PMID: 37610224 PMCID: PMC10508139 DOI: 10.1128/aac.00474-23] [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: 04/11/2023] [Accepted: 06/30/2023] [Indexed: 08/24/2023] Open
Abstract
Nitro-containing compounds have emerged as important agents in the control of tuberculosis (TB). From a whole-cell high-throughput screen for Mycobacterium tuberculosis (Mtb) growth inhibitors, 10 nitro-containing compounds were prioritized for characterization and mechanism of action studies. HC2209, HC2210, and HC2211 are nitrofuran-based prodrugs that need the cofactor F420 machinery for activation. Unlike pretomanid which depends only on deazaflavin-dependent nitroreductase (Ddn), these nitrofurans depend on Ddn and possibly another F420-dependent reductase for activation. These nitrofurans also differ from pretomanid in their potent activity against Mycobacterium abscessus. Four dinitrobenzamides (HC2217, HC2226, HC2238, and HC2239) and a nitrofuran (HC2250) are proposed to be inhibitors of decaprenyl-phosphoryl-ribose 2'-epimerase 1 (DprE1), based on isolation of resistant mutations in dprE1. Unlike other DprE1 inhibitors, HC2250 was found to be potent against non-replicating persistent bacteria, suggesting additional targets. Two of the compounds, HC2233 and HC2234, were found to have potent, sterilizing activity against replicating and non-replicating Mtb in vitro, but a proposed mechanism of action could not be defined. In a pilot in vivo efficacy study, HC2210 was orally bioavailable and efficacious in reducing bacterial load by ~1 log in a chronic murine TB infection model.
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Affiliation(s)
- Ifeanyichukwu E. Eke
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - John T. Williams
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Elizabeth R. Haiderer
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Veronica J. Albrecht
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Heather M. Murdoch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Bassel J. Abdalla
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Robert B. Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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6
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Olaitan AO, Dureja C, Youngblom MA, Topf MA, Shen WJ, Gonzales-Luna AJ, Deshpande A, Hevener KE, Freeman J, Wilcox MH, Palmer KL, Garey KW, Pepperell CS, Hurdle JG. Decoding a cryptic mechanism of metronidazole resistance among globally disseminated fluoroquinolone-resistant Clostridioides difficile. Nat Commun 2023; 14:4130. [PMID: 37438331 DOI: 10.1038/s41467-023-39429-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 06/13/2023] [Indexed: 07/14/2023] Open
Abstract
Severe outbreaks and deaths have been linked to the emergence and global spread of fluoroquinolone-resistant Clostridioides difficile over the past two decades. At the same time, metronidazole, a nitro-containing antibiotic, has shown decreasing clinical efficacy in treating C. difficile infection (CDI). Most metronidazole-resistant C. difficile exhibit an unusual resistance phenotype that can only be detected in susceptibility tests using molecularly intact heme. Here, we describe the mechanism underlying this trait. We find that most metronidazole-resistant C. difficile strains carry a T-to-G mutation (which we term PnimBG) in the promoter of gene nimB, resulting in constitutive transcription. Silencing or deleting nimB eliminates metronidazole resistance. NimB is related to Nim proteins that are known to confer resistance to nitroimidazoles. We show that NimB is a heme-dependent flavin enzyme that degrades nitroimidazoles to amines lacking antimicrobial activity. Furthermore, occurrence of the PnimBG mutation is associated with a Thr82Ile substitution in DNA gyrase that confers fluoroquinolone resistance in epidemic strains. Our findings suggest that the pandemic of fluoroquinolone-resistant C. difficile occurring over the past few decades has also been characterized by widespread resistance to metronidazole.
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Affiliation(s)
- Abiola O Olaitan
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Madison A Youngblom
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Madeline A Topf
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Wan-Jou Shen
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Anne J Gonzales-Luna
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, TX, USA
| | - Aditi Deshpande
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Kirk E Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jane Freeman
- Department of Microbiology, Leeds Teaching Hospitals Trust, Leeds, UK
- Healthcare Associated Infection Research Group, School of Medicine, University of Leeds, Leeds, UK
| | - Mark H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals Trust, Leeds, UK
- Healthcare Associated Infection Research Group, School of Medicine, University of Leeds, Leeds, UK
| | - Kelli L Palmer
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, TX, USA
| | - Caitlin S Pepperell
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, WI, USA.
| | - Julian G Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA.
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7
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Kang SW, Antoney J, Frkic RL, Lupton DW, Speight R, Scott C, Jackson CJ. Asymmetric Ene-Reduction of α,β-Unsaturated Compounds by F 420-Dependent Oxidoreductases A Enzymes from Mycobacterium smegmatis. Biochemistry 2023; 62:873-891. [PMID: 36637210 DOI: 10.1021/acs.biochem.2c00557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
The stereoselective reduction of alkenes conjugated to electron-withdrawing groups by ene-reductases has been extensively applied to the commercial preparation of fine chemicals. Although several different enzyme families are known to possess ene-reductase activity, the old yellow enzyme (OYE) family has been the most thoroughly investigated. Recently, it was shown that a subset of ene-reductases belonging to the flavin/deazaflavin oxidoreductase (FDOR) superfamily exhibit enantioselectivity that is generally complementary to that seen in the OYE family. These enzymes belong to one of several FDOR subgroups that use the unusual deazaflavin cofactor F420. Here, we explore several enzymes of the FDOR-A subgroup, characterizing their substrate range and enantioselectivity with 20 different compounds, identifying enzymes (MSMEG_2027 and MSMEG_2850) that could reduce a wide range of compounds stereoselectively. For example, MSMEG_2027 catalyzed the complete conversion of both isomers of citral to (R)-citronellal with 99% ee, while MSMEG_2850 catalyzed complete conversion of ketoisophorone to (S)-levodione with 99% ee. Protein crystallography combined with computational docking has allowed the observed stereoselectivity to be mechanistically rationalized for two enzymes. These findings add further support for the FDOR and OYE families of ene-reductases displaying general stereocomplementarity to each other and highlight their potential value in asymmetric ene-reduction.
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Affiliation(s)
- Suk Woo Kang
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia.,Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung25451, Republic of Korea
| | - James Antoney
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia.,School of Biology and Environmental Sciences, Queensland University of Technology, Brisbane, Queensland4000, Australia.,ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, Queensland4000, Australia
| | - Rebecca L Frkic
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia.,ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
| | - David W Lupton
- School of Chemistry, Monash University, Melbourne, Victoria3800, Australia
| | - Robert Speight
- School of Biology and Environmental Sciences, Queensland University of Technology, Brisbane, Queensland4000, Australia.,ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, Queensland4000, Australia
| | - Colin Scott
- Land and Water, Commonwealth Scientific and Industrial Research Organisation, Clayton, Victoria3168, Australia.,CSIRO Synthetic Biology Future Science Platform, GPO Box 1700, Canberra, Australian Capital Territory2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia.,ARC Centre of Excellence in Synthetic Biology, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia.,ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory2601, Australia
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8
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Kang SW, Antoney J, Lupton DW, Speight R, Scott C, Jackson CJ. Asymmetric Ene-Reduction by F 420 -Dependent Oxidoreductases B (FDOR-B) from Mycobacterium smegmatis. Chembiochem 2023; 24:e202200797. [PMID: 36716144 DOI: 10.1002/cbic.202200797] [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: 12/29/2022] [Revised: 01/29/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
Asymmetric reduction by ene-reductases has received considerable attention in recent decades. While several enzyme families possess ene-reductase activity, the Old Yellow Enzyme (OYE) family has received the most scientific and industrial attention. However, there is a limited substrate range and few stereocomplementary pairs of current ene-reductases, necessitating the development of a complementary class. Flavin/deazaflavin oxidoreductases (FDORs) that use the uncommon cofactor F420 have recently gained attention as ene-reductases for use in biocatalysis due to their stereocomplementarity with OYEs. Although the enzymes of the FDOR-As sub-group have been characterized in this context and reported to catalyse ene-reductions enantioselectively, enzymes from the similarly large, but more diverse, FDOR-B sub-group have not been investigated in this context. In this study, we investigated the activity of eight FDOR-B enzymes distributed across this sub-group, evaluating their specific activity, kinetic properties, and stereoselectivity against α,β-unsaturated compounds. The stereochemical outcomes of the FDOR-Bs are compared with enzymes of the FDOR-A sub-group and OYE family. Computational modelling and induced-fit docking are used to rationalize the observed catalytic behaviour and proposed a catalytic mechanism.
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Affiliation(s)
- Suk Woo Kang
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia.,Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung, 25451 (Republic of, Korea
| | - James Antoney
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia.,School of Biology and Environmental Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia.,ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, Queensland, 4000, Australia
| | - David W Lupton
- School of Chemistry, Monash University, Melbourne, Victoria, 3800, Australia
| | - Robert Speight
- School of Biology and Environmental Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia.,ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, Queensland, 4000, Australia
| | - Colin Scott
- Environment, Commonwealth Scientific and Industrial Research Organization, GPO Box 1700, Canberra, ACT 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia.,ARC Centre of Excellence in Synthetic Biology, Australian National University, Canberra, ACT 2601, Australia.,ARC Centre of Excellence for Innovations in Peptide and Protein Science, Australian National University, Canberra, ACT 2601, Australia
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9
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Sierra J, McQuinn RP, Leon P. The role of carotenoids as a source of retrograde signals: impact on plant development and stress responses. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7139-7154. [PMID: 35776102 DOI: 10.1093/jxb/erac292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Communication from plastids to the nucleus via retrograde signal cascades is essential to modulate nuclear gene expression, impacting plant development and environmental responses. Recently, a new class of plastid retrograde signals has emerged, consisting of acyclic and cyclic carotenoids and/or their degradation products, apocarotenoids. Although the biochemical identity of many of the apocarotenoid signals is still under current investigation, the examples described herein demonstrate the central roles that these carotenoid-derived signals play in ensuring plant development and survival. We present recent advances in the discovery of apocarotenoid signals and their role in various plant developmental transitions and environmental stress responses. Moreover, we highlight the emerging data exposing the highly complex signal transduction pathways underlying plastid to nucleus apocarotenoid retrograde signaling cascades. Altogether, this review summarizes the central role of the carotenoid pathway as a major source of retrograde signals in plants.
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Affiliation(s)
- Julio Sierra
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad, Ciudada de México, México
| | - Ryan P McQuinn
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Patricia Leon
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad, Ciudada de México, México
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10
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Ang CW, Lee BM, Jackson CJ, Wang Y, Franzblau SG, Francisco AF, Kelly JM, Bernhardt PV, Tan L, West NP, Sykes ML, Hinton AO, Bolisetti R, Avery VM, Cooper MA, Blaskovich MA. Nitroimidazopyrazinones with Oral Activity against Tuberculosis and Chagas Disease in Mouse Models of Infection. J Med Chem 2022; 65:13125-13142. [DOI: 10.1021/acs.jmedchem.2c00972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chee Wei Ang
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
- School of Science, Monash University Malaysia, Subang Jaya, 47500 Selangor, Malaysia
| | - Brendon M. Lee
- Research School of Chemistry, Australian National University, Sullivans Creek Road, Acton ACT 2601, Australia
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical College, New York, New York 10021, United States
| | - Colin J. Jackson
- Research School of Chemistry, Australian National University, Sullivans Creek Road, Acton ACT 2601, Australia
| | - Yuehong Wang
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Amanda F. Francisco
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - John M. Kelly
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Paul V. Bernhardt
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Melissa L. Sykes
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
| | - Alexandra O. Hinton
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Raghu Bolisetti
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Vicky M. Avery
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Don Young Road, Nathan, Queensland 4111, Australia
- School of Environment and Science, Griffith University, Nathan, Queensland 4111, Australia
| | - Matthew A. Cooper
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Mark A.T. Blaskovich
- Center for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
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11
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Perera M, Wijesundera S, Wijayarathna CD, Seneviratne G, Jayasena S. Identification of long-chain alkane-degrading (LadA) monooxygenases in Aspergillus flavus via in silico analysis. Front Microbiol 2022; 13:898456. [PMID: 36110294 PMCID: PMC9468676 DOI: 10.3389/fmicb.2022.898456] [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: 03/17/2022] [Accepted: 07/20/2022] [Indexed: 11/25/2022] Open
Abstract
Efficient degradation of alkanes in crude oil by the isolated Aspergillus flavus MM1 alluded to the presence of highly active alkane-degrading enzymes in this fungus. A long-chain alkane-degrading, LadA-like enzyme family in A. flavus was identified, and possible substrate-binding modes were analyzed using a computational approach. By analyzing publicly available protein databases, we identified six uncharacterized proteins in A. flavus NRRL 3357, of which five were identified as class LadAα and one as class LadAβ, which are eukaryotic homologs of bacterial long-chain alkane monooxygenase (LadA). Computational models of A. flavus LadAα homologs (Af1-Af5) showed overall structural similarity to the bacterial LadA and the unique sequence and structural elements that bind the cofactor Flavin mononucleotide (FMN). A receptor-cofactor-substrate docking protocol was established and validated to demonstrate the substrate binding in the A. flavus LadAα homologs. The modeled Af1, Af3, Af4, and Af5 captured long-chain n-alkanes inside the active pocket, above the bound FMN. Isoalloxazine ring of reduced FMN formed a π–alkyl interaction with the terminal carbon atom of captured alkanes, C16–C30, in Af3–Af5 and C16–C24 in Af1. Our results confirmed the ability of identified A. flavus LadAα monooxygenases to bind long-chain alkanes inside the active pocket. Hence A. flavus LadAα monooxygenases potentially initiate the degradation of long-chain alkanes by oxidizing bound long-chain alkanes into their corresponding alcohol.
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Affiliation(s)
- Madushika Perera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Sulochana Wijesundera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | | | | | - Sharmila Jayasena
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
- *Correspondence: Sharmila Jayasena,
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12
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Singh R, Shaheer M, Sobhia ME. Molecular dynamic assisted investigation on impact of mutations in deazaflavin dependent nitroreductase against pretomanid: a computational study. J Biomol Struct Dyn 2022:1-23. [PMID: 35574601 DOI: 10.1080/07391102.2022.2069156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the past decade, TB drugs belonging to the nitroimidazole class, pretomanid and delamanid, have been authorised to treat MDR-TB and XDR-TB. With a novel inhibition mechanism and a reduction in the span of treatment, it is now being administered in various combinations. This approach is not the ultimate remedy since the target protein Deazaflavin dependent nitroreductase (Ddn) has a high mutation frequency, and already pretomanid resistant clinical isolates are reported in various studies. Ddn is essential for M.tuberculosis to emerge from hypoxia, and point mutations in critical residues confer resistance to Nitro-imidazoles. Among the pool of available mutants, we have selected seven mutants viz DdnL49P, DdnY65S, DdnS78Y, DdnK79Q, DdnW88R, DdnY133C, and DdnY136S, all of which exhibited resistance to pretomanid. To address this issue, through computational study primarily by MD simulation, we attempted to elucidate these point mutations' impact and investigate the resistance mechanism. Hence, the DdnWT and mutant (MT) complexes were subjected to all-atom molecular dynamics (MD) simulations for 100 ns. Interestingly, we observed the escalation of the distance between cofactor and ligand in some mutants, along with a significant change in ligand conformation relative to the DdnWT. Moreover, we confirmed that mutations rendered ligand instability and were ejected from the binding pocket as a result. In conclusion, the results obtained provide a new structural insight and vital clues for designing novel inhibitors to combat nitroimidazole resistanceCommunicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ravi Singh
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Punjab, India
| | - Muhammed Shaheer
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Punjab, India
| | - M Elizabeth Sobhia
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Punjab, India
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13
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Cofactor F420, an emerging redox power in biosynthesis of secondary metabolites. Biochem Soc Trans 2022; 50:253-267. [PMID: 35191491 DOI: 10.1042/bst20211286] [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: 12/11/2021] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 02/07/2023]
Abstract
Cofactor F420 is a low-potential hydride-transfer deazaflavin that mediates important oxidoreductive reactions in the primary metabolism of archaea and a wide range of bacteria. Over the past decade, biochemical studies have demonstrated another essential role for F420 in the biosynthesis of various classes of natural products. These studies have substantiated reports predating the structural determination of F420 that suggested a potential role for F420 in the biosynthesis of several antibiotics produced by Streptomyces. In this article, we focus on this exciting and emerging role of F420 in catalyzing the oxidoreductive transformation of various imine, ketone and enoate moieties in secondary metabolites. Given the extensive and increasing availability of genomic and metagenomic data, these F420-dependent transformations may lead to the discovery of novel secondary metabolites, providing an invaluable and untapped resource in various biotechnological applications.
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14
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Grinter R, Greening C. Cofactor F420: an expanded view of its distribution, biosynthesis and roles in bacteria and archaea. FEMS Microbiol Rev 2021; 45:fuab021. [PMID: 33851978 PMCID: PMC8498797 DOI: 10.1093/femsre/fuab021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/11/2021] [Indexed: 12/11/2022] Open
Abstract
Many bacteria and archaea produce the redox cofactor F420. F420 is structurally similar to the cofactors FAD and FMN but is catalytically more similar to NAD and NADP. These properties allow F420 to catalyze challenging redox reactions, including key steps in methanogenesis, antibiotic biosynthesis and xenobiotic biodegradation. In the last 5 years, there has been much progress in understanding its distribution, biosynthesis, role and applications. Whereas F420 was previously thought to be confined to Actinobacteria and Euryarchaeota, new evidence indicates it is synthesized across the bacterial and archaeal domains, as a result of extensive horizontal and vertical biosynthetic gene transfer. F420 was thought to be synthesized through one biosynthetic pathway; however, recent advances have revealed variants of this pathway and have resolved their key biosynthetic steps. In parallel, new F420-dependent biosynthetic and metabolic processes have been discovered. These advances have enabled the heterologous production of F420 and identified enantioselective F420H2-dependent reductases for biocatalysis. New research has also helped resolve how microorganisms use F420 to influence human and environmental health, providing opportunities for tuberculosis treatment and methane mitigation. A total of 50 years since its discovery, multiple paradigms associated with F420 have shifted, and new F420-dependent organisms and processes continue to be discovered.
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Affiliation(s)
- Rhys Grinter
- Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Chris Greening
- Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
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15
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Mascotti ML, Juri Ayub M, Fraaije MW. On the diversity of F 420 -dependent oxidoreductases: A sequence- and structure-based classification. Proteins 2021; 89:1497-1507. [PMID: 34216160 PMCID: PMC8518648 DOI: 10.1002/prot.26170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/30/2021] [Accepted: 06/26/2021] [Indexed: 11/05/2022]
Abstract
The F420 deazaflavin cofactor is an intriguing molecule as it structurally resembles the canonical flavin cofactor, although behaves as a nicotinamide cofactor due to its obligate hydride-transfer reactivity and similar low redox potential. Since its discovery, numerous enzymes relying on it have been described. The known deazaflavoproteins are taxonomically restricted to Archaea and Bacteria. The biochemistry of the deazaflavoenzymes is diverse and they exhibit great structural variability. In this study a thorough sequence and structural homology evolutionary analysis was performed in order to generate an overarching classification of the F420 -dependent oxidoreductases. Five different deazaflavoenzyme Classes (I-V) are described according to their structural folds as follows: Class I encompassing the TIM-barrel F420 -dependent enzymes; Class II including the Rossmann fold F420 -dependent enzymes; Class III comprising the β-roll F420 -dependent enzymes; Class IV which exclusively gathers the SH3 barrel F420 -dependent enzymes and Class V including the three layer ββα sandwich F420 -dependent enzymes. This classification provides a framework for the identification and biochemical characterization of novel deazaflavoenzymes.
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Affiliation(s)
- María Laura Mascotti
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands.,IMIBIO-SL CONICET, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
| | - Maximiliano Juri Ayub
- IMIBIO-SL CONICET, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
| | - Marco W Fraaije
- Molecular Enzymology Group, University of Groningen, Groningen, The Netherlands
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16
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The adaptive landscape of a metallo-enzyme is shaped by environment-dependent epistasis. Nat Commun 2021; 12:3867. [PMID: 34162839 PMCID: PMC8222346 DOI: 10.1038/s41467-021-23943-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 05/18/2021] [Indexed: 11/08/2022] Open
Abstract
Enzymes can evolve new catalytic activity when environmental changes present them with novel substrates. Despite this seemingly straightforward relationship, factors other than the direct catalytic target can also impact adaptation. Here, we characterize the catalytic activity of a recently evolved bacterial methyl-parathion hydrolase for all possible combinations of the five functionally relevant mutations under eight different laboratory conditions (in which an alternative divalent metal is supplemented). The resultant adaptive landscapes across this historical evolutionary transition vary in terms of both the number of “fitness peaks” as well as the genotype(s) at which they are found as a result of genotype-by-environment interactions and environment-dependent epistasis. This suggests that adaptive landscapes may be fluid and molecular adaptation is highly contingent not only on obvious factors (such as catalytic targets), but also on less obvious secondary environmental factors that can direct it towards distinct outcomes. The metaphor of an adaptive landscape is presented quantitatively by looking at molecular adaptations and their catalytic consequences in a recently evolved bacterial enzyme. The study identifies both genotype-by-environment interactions and environment-dependent epistasis as factors that can alter the fitness of functional mutations.
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17
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Potency boost of a Mycobacterium tuberculosis dihydrofolate reductase inhibitor by multienzyme F 420H 2-dependent reduction. Proc Natl Acad Sci U S A 2021; 118:2025172118. [PMID: 34161270 PMCID: PMC8237569 DOI: 10.1073/pnas.2025172118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial metabolism can cause intrinsic drug resistance but can also convert inactive parent drugs into bioactive derivatives, as is the case for several antimycobacterial prodrugs. Here, we show that the intrabacterial metabolism of a Mtb dihydrofolate reductase (DHFR) inhibitor with moderate affinity for its target boosts its on-target activity by two orders of magnitude. This is a “prodrug-like” antimycobacterial that possesses baseline activity in the absence of intracellular bioactivation. By elucidating the metabolic enhancement mechanism, we have provided the basis for the rational optimization of a class of DHFR inhibitors and uncovered an antibacterial drug discovery concept. Triaza-coumarin (TA-C) is a Mycobacterium tuberculosis (Mtb) dihydrofolate reductase (DHFR) inhibitor with an IC50 (half maximal inhibitory concentration) of ∼1 µM against the enzyme. Despite this moderate target inhibition, TA-C shows exquisite antimycobacterial activity (MIC50, concentration inhibiting growth by 50% = 10 to 20 nM). Here, we investigated the mechanism underlying this potency disconnect. To confirm that TA-C targets DHFR and investigate its unusual potency pattern, we focused on resistance mechanisms. In Mtb, resistance to DHFR inhibitors is frequently associated with mutations in thymidylate synthase thyA, which sensitizes Mtb to DHFR inhibition, rather than in DHFR itself. We observed thyA mutations, consistent with TA-C interfering with the folate pathway. A second resistance mechanism involved biosynthesis of the redox coenzyme F420. Thus, we hypothesized that TA-C may be metabolized by Mtb F420–dependent oxidoreductases (FDORs). By chemically blocking the putative site of FDOR-mediated reduction in TA-C, we reproduced the F420-dependent resistance phenotype, suggesting that F420H2-dependent reduction is required for TA-C to exert its potent antibacterial activity. Indeed, chemically synthesized TA-C-Acid, the putative product of TA-C reduction, displayed a 100-fold lower IC50 against DHFR. Screening seven recombinant Mtb FDORs revealed that at least two of these enzymes reduce TA-C. This redundancy in activation explains why no mutations in the activating enzymes were identified in the resistance screen. Analysis of the reaction products confirmed that FDORs reduce TA-C at the predicted site, yielding TA-C-Acid. This work demonstrates that intrabacterial metabolism converts TA-C, a moderately active “prodrug,” into a 100-fold-more-potent DHFR inhibitor, thus explaining the disconnect between enzymatic and whole-cell activity.
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18
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A noncanonical heme oxygenase specific for the degradation of c-type heme. J Biol Chem 2021; 296:100666. [PMID: 33862082 PMCID: PMC8131568 DOI: 10.1016/j.jbc.2021.100666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 11/24/2022] Open
Abstract
Heme oxygenases (HOs) play a critical role in recouping iron from the labile heme pool. The acquisition and liberation of heme iron are especially important for the survival of pathogenic bacteria. All characterized HOs, including those belonging to the HugZ superfamily, preferentially cleave free b-type heme. Another common form of heme found in nature is c-type heme, which is covalently linked to proteinaceous cysteine residues. However, mechanisms for direct iron acquisition from the c-type heme pool are unknown. Here we identify a HugZ homolog from the oligopeptide permease (opp) gene cluster of Paracoccus denitrificans that lacks any observable reactivity with heme b and show that it instead rapidly degrades c-type hemopeptides. This c-type heme oxygenase catalyzes the oxidative cleavage of the model substrate microperoxidase-11 at the β- and/or δ-meso position(s), yielding the corresponding peptide-linked biliverdin, CO, and free iron. X-ray crystallographic analysis suggests that the switch in substrate specificity from b-to c-type heme involves loss of the N-terminal α/β domain and C-terminal loop containing the coordinating histidine residue characteristic of HugZ homologs, thereby accommodating a larger substrate that provides its own iron ligand. These structural features are also absent in certain heme utilization/storage proteins from human pathogens that exhibit low or no HO activity with free heme. This study thus expands the scope of known iron acquisition strategies to include direct oxidative cleavage of heme-containing proteolytic fragments of c-type cytochromes and helps to explain why certain oligopeptide permeases show specificity for the import of heme in addition to peptides.
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19
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Spence MA, Mortimer MD, Buckle AM, Minh BQ, Jackson CJ. A Comprehensive Phylogenetic Analysis of the Serpin Superfamily. Mol Biol Evol 2021; 38:2915-2929. [PMID: 33744972 PMCID: PMC8233489 DOI: 10.1093/molbev/msab081] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Serine protease inhibitors (serpins) are found in all kingdoms of life and play essential roles in multiple physiological processes. Owing to the diversity of the superfamily, phylogenetic analysis is challenging and prokaryotic serpins have been speculated to have been acquired from Metazoa through horizontal gene transfer due to their unexpectedly high homology. Here, we have leveraged a structural alignment of diverse serpins to generate a comprehensive 6,000-sequence phylogeny that encompasses serpins from all kingdoms of life. We show that in addition to a central “hub” of highly conserved serpins, there has been extensive diversification of the superfamily into many novel functional clades. Our analysis indicates that the hub proteins are ancient and are similar because of convergent evolution, rather than the alternative hypothesis of horizontal gene transfer. This work clarifies longstanding questions in the evolution of serpins and provides new directions for research in the field of serpin biology.
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Affiliation(s)
- Matthew A Spence
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
| | - Matthew D Mortimer
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
| | - Ashley M Buckle
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC, Australia
| | - Bui Quang Minh
- Research School of Computing and Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia.,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT, Australia.,Australian Research Council Centre of Excellence in Synthetic Biology, Research School of Chemistry, Australian National University, Canberra, ACT, Australia
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20
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Wang J, Guo Q, Li X, Wang X, Liu L. The Arabidopsis locus AT3G03890 encodes a dimeric β-barrel protein implicated in heme degradation. Biochem J 2020; 477:BCJ20200712. [PMID: 33284325 DOI: 10.1042/bcj20200712] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 02/24/2024]
Abstract
Plant tetrapyrroles, including heme and bilins, are synthesized in plastids. Heme oxygenase (HO) catalyzes the oxidative cleavage of heme to the linear tetrapyrrole biliverdin as the initial step in bilin biosynthesis. Besides the canonical α-helical HO that is conserved from prokaryotes to human, a subfamily of non-canonical dimeric β-barrel HO has been found in bacteria. In this work, we discovered that the Arabidopsis locus AT3G03890 encodes a dimeric β-barrel protein that is structurally related to the putative non-canonical HO and is located in chloroplasts. The recombinant protein was able to bind and degrade heme in a manner different from known HO proteins. Crystal structure of the heme-protein complex reveals that the heme-binding site is in the interdimer interface and the heme iron is coordinated by a fixed water molecule. Our results identify a new protein that may function additionally in the tetrapyrrole biosynthetic pathway.
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Affiliation(s)
| | - Qi Guo
- Institute of Botany, Chinease Academy of Sciences, Beijing, China
| | - Xiaoyi Li
- Institute of Botany, Chinease Academy of Sciences, Beijing, China
| | | | - Lin Liu
- Anhui University, Hefei, China
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21
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Convergent pathways to biosynthesis of the versatile cofactor F 420. Curr Opin Struct Biol 2020; 65:9-16. [PMID: 32570108 DOI: 10.1016/j.sbi.2020.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/05/2020] [Accepted: 05/09/2020] [Indexed: 10/24/2022]
Abstract
Cofactor F420 is historically known as the methanogenic redox cofactor, having a key role in the central metabolism of methanogens, and archaea in general. Over the past decade, however, it has become evident this cofactor is more widely distributed across archaeal and bacterial taxa, suggesting a broader role for F420 in various metabolic and ecological capacities. In this article, we focus on the recent findings that have led to a deeper understanding of F420 biosynthetic enzymes and metabolites across microorganisms.
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22
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Lee BM, Harold LK, Almeida DV, Afriat-Jurnou L, Aung HL, Forde BM, Hards K, Pidot SJ, Ahmed FH, Mohamed AE, Taylor MC, West NP, Stinear TP, Greening C, Beatson SA, Nuermberger EL, Cook GM, Jackson CJ. Predicting nitroimidazole antibiotic resistance mutations in Mycobacterium tuberculosis with protein engineering. PLoS Pathog 2020; 16:e1008287. [PMID: 32032366 PMCID: PMC7032734 DOI: 10.1371/journal.ppat.1008287] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/20/2020] [Accepted: 12/16/2019] [Indexed: 12/21/2022] Open
Abstract
Our inability to predict which mutations could result in antibiotic resistance has made it difficult to rapidly identify the emergence of resistance, identify pre-existing resistant populations, and manage our use of antibiotics to effectively treat patients and prevent or slow the spread of resistance. Here we investigated the potential for resistance against the new antitubercular nitroimidazole prodrugs pretomanid and delamanid to emerge in Mycobacterium tuberculosis, the causative agent of tuberculosis (TB). Deazaflavin-dependent nitroreductase (Ddn) is the only identified enzyme within M. tuberculosis that activates these prodrugs, via an F420H2-dependent reaction. We show that the native menaquinone-reductase activity of Ddn is essential for emergence from hypoxia, which suggests that for resistance to spread and pose a threat to human health, the native activity of Ddn must be at least partially retained. We tested 75 unique mutations, including all known sequence polymorphisms identified among ~15,000 sequenced M. tuberculosis genomes. Several mutations abolished pretomanid and delamanid activation in vitro, without causing complete loss of the native activity. We confirmed that a transmissible M. tuberculosis isolate from the hypervirulent Beijing family already possesses one such mutation and is resistant to pretomanid, before being exposed to the drug. Notably, delamanid was still effective against this strain, which is consistent with structural analysis that indicates delamanid and pretomanid bind to Ddn differently. We suggest that the mutations identified in this work be monitored for informed use of delamanid and pretomanid treatment and to slow the emergence of resistance.
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Affiliation(s)
- Brendon M. Lee
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Liam K. Harold
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Deepak V. Almeida
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Livnat Afriat-Jurnou
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia
- MIGAL, Galilee Research Institute, Kiryat Shmona, Israel
- Faculty of Sciences and Technology, Tel-Hai Academic College, Upper Galilee, Israel
| | - Htin Lin Aung
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Brian M. Forde
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Kiel Hards
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Sacha J. Pidot
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria, Australia
| | - F. Hafna Ahmed
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia
| | - A. Elaaf Mohamed
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Matthew C. Taylor
- Land and Water Flagship, The Commonwealth Scientific and Industrial Organisation, Canberra, Australian Capital Territory, Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria, Australia
| | - Chris Greening
- Land and Water Flagship, The Commonwealth Scientific and Industrial Organisation, Canberra, Australian Capital Territory, Australia
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Scott A. Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Eric L. Nuermberger
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Gregory M. Cook
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Colin J. Jackson
- Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia
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23
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Steiningerova L, Kamenik Z, Gazak R, Kadlcik S, Bashiri G, Man P, Kuzma M, Pavlikova M, Janata J. Different Reaction Specificities of F 420H 2-Dependent Reductases Facilitate Pyrrolobenzodiazepines and Lincomycin To Fit Their Biological Targets. J Am Chem Soc 2020; 142:3440-3448. [PMID: 31944685 DOI: 10.1021/jacs.9b11234] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Antitumor pyrrolobenzodiazepines (PBDs), lincosamide antibiotics, quorum-sensing molecule hormaomycin, and antimicrobial griselimycin are structurally and functionally diverse groups of actinobacterial metabolites. The common feature of these compounds is the incorporation of l-tyrosine- or l-leucine-derived 4-alkyl-l-proline derivatives (APDs) in their structures. Here, we report that the last reaction in the biosynthetic pathway of APDs, catalyzed by F420H2-dependent Apd6 reductases, contributes to the structural diversity of APD precursors. Specifically, the heterologous overproduction of six Apd6 enzymes demonstrated that Apd6 from the biosynthesis of PBDs and hormaomycin can reduce only an endocyclic imine double bond, whereas Apd6 LmbY and partially GriH from the biosyntheses of lincomycin and griselimycin, respectively, also reduce the more inert exocyclic double bond of the same 4-substituted Δ1-pyrroline-2-carboxylic acid substrate, making LmbY and GriH unusual, if not unique, among reductases. Furthermore, the differences in the reaction specificity of the Apd6 reductases determine the formation of the fully saturated APD moiety of lincomycin versus the unsaturated APD moiety of PBDs, providing molecules with optimal shapes to bind their distinct biological targets. Moreover, the Apd6 reductases establish the first F420H2-dependent enzymes from the luciferase-like hydride transferase protein superfamily in the biosynthesis of bioactive molecules. Finally, our bioinformatics analysis demonstrates that Apd6 and their homologues, widely distributed within several bacterial phyla, play a role in the formation of novel yet unknown natural products with incorporated l-proline-like precursors and likely in the microbial central metabolism.
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Affiliation(s)
- Lucie Steiningerova
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic.,Department of Genetics and Microbiology, Faculty of Science , Charles University in Prague , Vinicna 5 , 128 00 Praha 2 , Czech Republic
| | - Zdenek Kamenik
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic.,Institute of Microbiology, v.v.i., BIOCEV, Czech Academy of Sciences , 252 50 Vestec , Czech Republic
| | - Radek Gazak
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic
| | - Stanislav Kadlcik
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic
| | - Ghader Bashiri
- Laboratory of Structural Biology and Maurice Wilkins Center for Molecular Biodiscovery, School of Biological Sciences , University of Auckland , Auckland 1010 , New Zealand
| | - Petr Man
- Institute of Microbiology, v.v.i., BIOCEV, Czech Academy of Sciences , 252 50 Vestec , Czech Republic
| | - Marek Kuzma
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic
| | - Magdalena Pavlikova
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic
| | - Jiri Janata
- Institute of Microbiology, v.v.i., Czech Academy of Sciences , Videnska 1083 , 142 20 Praha 4 , Czech Republic
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24
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Chao A, Burley KH, Sieminski PJ, de Miranda R, Chen X, Mobley DL, Goulding CW. Structure of a Mycobacterium tuberculosis Heme-Degrading Protein, MhuD, Variant in Complex with Its Product. Biochemistry 2019; 58:4610-4620. [PMID: 31638374 DOI: 10.1021/acs.biochem.9b00726] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, requires iron for survival. In Mtb, MhuD is the cytosolic protein that degrades imported heme. MhuD is distinct, in both sequence and structure, from canonical heme oxygenases (HOs) but homologous with IsdG-type proteins. Canonical HO is found mainly in eukaryotes, while IsdG-type proteins are predominantly found in prokaryotes, including pathogens. While there are several published structures of MhuD and other IsdG-type proteins in complex with the heme substrate, no structures of IsdG-type proteins in complex with a product have been reported, unlike the case for HOs. We recently showed that the Mtb variant MhuD-R26S produces biliverdin IXα (αBV) rather than the wild-type mycobilin isomers. Given that mycobilin and other IsdG-type protein products like staphylobilin are difficult to isolate in quantities sufficient for structure determination, here we use the MhuD-R26S variant and its product αBV as a proxy to study the IsdG-type protein-product complex. First, we show that αBV has a nanomolar affinity for MhuD and the R26S variant. Second, we determined the MhuD-R26S-αBV complex structure to 2.5 Å, which reveals two notable features: (1) two αBV molecules bound per active site and (2) a novel α-helix (α3) that was not observed in previous MhuD-heme structures. Finally, through molecular dynamics simulations, we show that α3 is stable with the proximal αBV alone. MhuD's high affinity for the product and the observed structural and electrostatic changes that accompany substrate turnover suggest that there may be an unidentified class of proteins that are responsible for the extraction of products from MhuD and other IsdG-type proteins.
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25
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Cofactor F420-Dependent Enzymes: An Under-Explored Resource for Asymmetric Redox Biocatalysis. Catalysts 2019. [DOI: 10.3390/catal9100868] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The asymmetric reduction of enoates, imines and ketones are among the most important reactions in biocatalysis. These reactions are routinely conducted using enzymes that use nicotinamide cofactors as reductants. The deazaflavin cofactor F420 also has electrochemical properties that make it suitable as an alternative to nicotinamide cofactors for use in asymmetric reduction reactions. However, cofactor F420-dependent enzymes remain under-explored as a resource for biocatalysis. This review considers the cofactor F420-dependent enzyme families with the greatest potential for the discovery of new biocatalysts: the flavin/deazaflavin-dependent oxidoreductases (FDORs) and the luciferase-like hydride transferases (LLHTs). The characterized F420-dependent reductions that have the potential for adaptation for biocatalysis are discussed, and the enzymes best suited for use in the reduction of oxidized cofactor F420 to allow cofactor recycling in situ are considered. Further discussed are the recent advances in the production of cofactor F420 and its functional analog FO-5′-phosphate, which remains an impediment to the adoption of this family of enzymes for industrial biocatalytic processes. Finally, the prospects for the use of this cofactor and dependent enzymes as a resource for industrial biocatalysis are discussed.
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26
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Drenth J, Trajkovic M, Fraaije MW. Chemoenzymatic Synthesis of an Unnatural Deazaflavin Cofactor That Can Fuel F420-Dependent Enzymes. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01506] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jeroen Drenth
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Milos Trajkovic
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Marco W. Fraaije
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
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27
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Benini S, Haouz A, Proux F, Alzari P, Wilson K. The crystal structure of Rv2991 from Mycobacterium tuberculosis: An F 420 binding protein with unknown function. J Struct Biol 2019; 206:216-224. [PMID: 30890426 DOI: 10.1016/j.jsb.2019.03.006] [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: 02/14/2019] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 11/25/2022]
Abstract
The crystal structure of the conserved hypothetical protein Rv2991 from Mycobacterium tuberculosis has been solved by SAD using seleno-methionine substituted protein. The dimeric biological assembly and the sequence and fold conservation are typical of F420 cofactor binding enzymes. Despite Rv2991 still being of unknown function, sequence and structural comparison with similar proteins enable a role to be proposed for its C-terminal stretch of residues in recognizing and orienting the substrate. In addition, the C-terminus is involved in both protein folding and determining the size of the active site cavity.
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Affiliation(s)
- Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano 39100, Italy.
| | - Ahmed Haouz
- C2RT-Plateforme de cristallographie, Institut Pasteur, CNRS UMR 3528, 75724 Paris Cedex 15, France
| | - Florence Proux
- C2RT-Plateforme de cristallographie, Institut Pasteur, CNRS UMR 3528, 75724 Paris Cedex 15, France
| | - Pedro Alzari
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université Paris Diderot, Sorbonne Paris Cité, 75724 Paris Cedex 15, France
| | - Keith Wilson
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
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28
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Varghese F, Kabasakal BV, Cotton CAR, Schumacher J, Rutherford AW, Fantuzzi A, Murray JW. A low-potential terminal oxidase associated with the iron-only nitrogenase from the nitrogen-fixing bacterium Azotobacter vinelandii. J Biol Chem 2019; 294:9367-9376. [PMID: 31043481 PMCID: PMC6579470 DOI: 10.1074/jbc.ra118.007285] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/26/2019] [Indexed: 11/06/2022] Open
Abstract
The biological route for nitrogen gas entering the biosphere is reduction to ammonia by the nitrogenase enzyme, which is inactivated by oxygen. Three types of nitrogenase exist, the least-studied of which is the iron-only nitrogenase. The Anf3 protein in the bacterium Rhodobacter capsulatus is essential for diazotrophic (i.e. nitrogen-fixing) growth with the iron-only nitrogenase, but its enzymatic activity and function are unknown. Here, we biochemically and structurally characterize Anf3 from the model diazotrophic bacterium Azotobacter vinelandii Determining the Anf3 crystal structure to atomic resolution, we observed that it is a dimeric flavocytochrome with an unusually close interaction between the heme and the FAD cofactors. Measuring the reduction potentials by spectroelectrochemical redox titration, we observed values of -420 ± 10 and -330 ± 10 mV for the two FAD potentials and -340 ± 1 mV for the heme. We further show that Anf3 accepts electrons from spinach ferredoxin and that Anf3 consumes oxygen without generating superoxide or hydrogen peroxide. We predict that Anf3 protects the iron-only nitrogenase from oxygen inactivation by functioning as an oxidase in respiratory protection, with flavodoxin or ferredoxin as the physiological electron donors.
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Affiliation(s)
- Febin Varghese
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Burak Veli Kabasakal
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Charles A R Cotton
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jörg Schumacher
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - A William Rutherford
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andrea Fantuzzi
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - James W Murray
- From the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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29
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Exploring the sequence, function, and evolutionary space of protein superfamilies using sequence similarity networks and phylogenetic reconstructions. Methods Enzymol 2019; 620:315-347. [PMID: 31072492 DOI: 10.1016/bs.mie.2019.03.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Integrative computational methods can facilitate the discovery of new protein functions and enzymatic reactions by enabling the observation and investigation of complex sequence-structure-function and evolutionary relationships within protein superfamilies. Here, we highlight the use of sequence similarity networks (SSNs) and phylogenetic reconstructions to map the functional divergence and evolutionary history of protein superfamilies. We exemplify this approach using the nitroreductase (NTR) flavoenzyme superfamily, demonstrating that SSN investigations can provide a rapid and effective means to classify groups of proteins, expose sequence similarity relationships across the global scale of a protein superfamily, and efficiently support detailed phylogenetic analyses. Integration of such approaches with systematic experimental characterization will expand our understanding of the functional diversity of enzymes, their evolution, and their associated physiological roles.
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30
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A revised biosynthetic pathway for the cofactor F 420 in prokaryotes. Nat Commun 2019; 10:1558. [PMID: 30952857 PMCID: PMC6450877 DOI: 10.1038/s41467-019-09534-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/13/2019] [Indexed: 01/19/2023] Open
Abstract
Cofactor F420 plays critical roles in primary and secondary metabolism in a range of bacteria and archaea as a low-potential hydride transfer agent. It mediates a variety of important redox transformations involved in bacterial persistence, antibiotic biosynthesis, pro-drug activation and methanogenesis. However, the biosynthetic pathway for F420 has not been fully elucidated: neither the enzyme that generates the putative intermediate 2-phospho-l-lactate, nor the function of the FMN-binding C-terminal domain of the γ-glutamyl ligase (FbiB) in bacteria are known. Here we present the structure of the guanylyltransferase FbiD and show that, along with its archaeal homolog CofC, it accepts phosphoenolpyruvate, rather than 2-phospho-l-lactate, as the substrate, leading to the formation of the previously uncharacterized intermediate dehydro-F420-0. The C-terminal domain of FbiB then utilizes FMNH2 to reduce dehydro-F420-0, which produces mature F420 species when combined with the γ-glutamyl ligase activity of the N-terminal domain. These new insights have allowed the heterologous production of F420 from a recombinant F420 biosynthetic pathway in Escherichia coli. Cofactor F420 plays crucial roles in bacterial and archaeal metabolism, but its biosynthetic pathway is not fully understood. Here, the authors present the structure of one of the enzymes and provide experimental evidence for a substantial revision of the pathway, including the identification of a new intermediate.
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31
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Harold LK, Antoney J, Ahmed FH, Hards K, Carr PD, Rapson T, Greening C, Jackson CJ, Cook GM. FAD-sequestering proteins protect mycobacteria against hypoxic and oxidative stress. J Biol Chem 2018; 294:2903-2912. [PMID: 30567740 DOI: 10.1074/jbc.ra118.006237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/14/2018] [Indexed: 12/13/2022] Open
Abstract
The ability to persist in the absence of growth triggered by low oxygen levels is a critical process for the survival of mycobacterial species in many environmental niches. MSMEG_5243 (fsq), a gene of unknown function in Mycobacterium smegmatis, is up-regulated in response to hypoxia and regulated by DosRDosS/DosT, an oxygen- and redox-sensing two-component system that is highly conserved in mycobacteria. In this communication, we demonstrate that MSMEG_5243 is a flavin-sequestering protein and henceforth refer to it as Fsq. Using an array of biochemical and structural analyses, we show that Fsq is a member of the diverse superfamily of flavin- and deazaflavin-dependent oxidoreductases (FDORs) and is widely distributed in mycobacterial species. We created a markerless deletion mutant of fsq and demonstrate that fsq is required for cell survival during hypoxia. Using fsq deletion and overexpression, we found that fsq enhances cellular resistance to hydrogen peroxide treatment. The X-ray crystal structure of Fsq, solved to 2.7 Å, revealed a homodimeric organization with FAD bound noncovalently. The Fsq structure also uncovered no potential substrate-binding cavities, as the FAD is fully enclosed, and electrochemical studies indicated that the Fsq:FAD complex is relatively inert and does not share common properties with electron-transfer proteins. Taken together, our results suggest that Fsq reduces the formation of reactive oxygen species (ROS) by sequestering free FAD during recovery from hypoxia, thereby protecting the cofactor from undergoing autoxidation to produce ROS. This finding represents a new paradigm in mycobacterial adaptation to hypoxia.
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Affiliation(s)
- Liam K Harold
- From the Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1042, New Zealand
| | - James Antoney
- Research School of Chemistry, The Australian National University, Canberra, Australia.,The Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship, Canberra, Australian Capital Territory, Australia, and
| | - F Hafna Ahmed
- Research School of Chemistry, The Australian National University, Canberra, Australia.,The Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship, Canberra, Australian Capital Territory, Australia, and
| | - Kiel Hards
- From the Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Paul D Carr
- Research School of Chemistry, The Australian National University, Canberra, Australia
| | - Trevor Rapson
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship, Canberra, Australian Capital Territory, Australia, and
| | - Chris Greening
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship, Canberra, Australian Capital Territory, Australia, and .,School of Biological Sciences, Monash University, Melbourne, Australia
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, Australia,
| | - Gregory M Cook
- From the Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand, .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1042, New Zealand
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32
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Reconstructing the evolutionary history of F 420-dependent dehydrogenases. Sci Rep 2018; 8:17571. [PMID: 30514849 PMCID: PMC6279831 DOI: 10.1038/s41598-018-35590-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
During the last decade the number of characterized F420-dependent enzymes has significantly increased. Many of these deazaflavoproteins share a TIM-barrel fold and are structurally related to FMN-dependent luciferases and monooxygenases. In this work, we traced the origin and evolutionary history of the F420-dependent enzymes within the luciferase-like superfamily. By a thorough phylogenetic analysis we inferred that the F420-dependent enzymes emerged from a FMN-dependent common ancestor. Furthermore, the data show that during evolution, the family of deazaflavoproteins split into two well-defined groups of enzymes: the F420-dependent dehydrogenases and the F420-dependent reductases. By such event, the dehydrogenases specialized in generating the reduced deazaflavin cofactor, while the reductases employ the reduced F420 for catalysis. Particularly, we focused on investigating the dehydrogenase subfamily and demonstrated that this group diversified into three types of dehydrogenases: the already known F420-dependent glucose-6-phosphate dehydrogenases, the F420-dependent alcohol dehydrogenases, and the sugar-6-phosphate dehydrogenases that were identified in this study. By reconstructing and experimentally characterizing ancestral and extant representatives of F420-dependent dehydrogenases, their biochemical properties were investigated and compared. We propose an evolutionary path for the emergence and diversification of the TIM-barrel fold F420-dependent dehydrogenases subfamily.
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33
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Mathew S, Trajkovic M, Kumar H, Nguyen QT, Fraaije MW. Enantio- and regioselective ene-reductions using F 420H 2-dependent enzymes. Chem Commun (Camb) 2018; 54:11208-11211. [PMID: 30230493 DOI: 10.1039/c8cc04449j] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In the past decade it has become clear that many microbes harbor enzymes that employ an unusual flavin cofactor, the F420 deazaflavin cofactor. Herein we show that F420-dependent reductases (FDRs) can successfully perform enantio-, regio- and chemoselective ene-reductions. For the first time, we have demonstrated that F420H2-driven reductases can be used as biocatalysts for the reduction of α,β-unsaturated ketones and aldehydes with good conversions (>99%) and excellent regioselectivities and enantiomeric excesses (>99% ee). Noteworthily, FDRs typically display an opposite enantioselectivity when compared to the well established FMN-dependent Old Yellow Enzymes (OYEs).
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Affiliation(s)
- Sam Mathew
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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34
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Ichikawa H, Bashiri G, Kelly WL. Biosynthesis of the Thiopeptins and Identification of an F 420H 2-Dependent Dehydropiperidine Reductase. J Am Chem Soc 2018; 140:10749-10756. [PMID: 30118217 PMCID: PMC6193465 DOI: 10.1021/jacs.8b04238] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Thiopeptins are highly decorated thiopeptide antibiotics similar in structure to thiostrepton A and harbor two unusual features. All thiopeptins contain a thioamide, a rare moiety among natural products, and a subset of thiopeptins present with a piperidine in the core macrocycle rather than the more oxidated dehydropiperidine or pyridine rings typically observed in the thiopeptides. Here, we report the identification of the thiopeptin biosynthetic gene ( tpn) cluster in Streptomyces tateyamensis and the gene product, TpnL, which shows sequence similarity to (deaza)flavin-dependent oxidoreductases. Heterologous expression of TpnL in the thiostrepton A producer Streptomyces laurentii led to the production of a piperidine-containing analogue. Binding studies revealed that TpnL preferentially binds the deazaflavin cofactor coenzyme F420, and in vitro reconstitution of TpnL activity confirmed that this enzyme is an F420H2-dependent dehydropiperidine reductase. The identification of TpnL and its activity establishes the basis for the piperidine-containing series a thiopeptides, one of the five main structural groups of this diverse family of antibiotics.
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Affiliation(s)
- Hiro Ichikawa
- School of Chemistry and Biochemistry and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ghader Bashiri
- Laboratory of Structural Biology and Maurice Wilkins Center for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Wendy L. Kelly
- School of Chemistry and Biochemistry and the Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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35
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Copp JN, Akiva E, Babbitt PC, Tokuriki N. Revealing Unexplored Sequence-Function Space Using Sequence Similarity Networks. Biochemistry 2018; 57:4651-4662. [PMID: 30052428 DOI: 10.1021/acs.biochem.8b00473] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rapidly expanding number of protein sequences found in public databases can improve our understanding of how protein functions evolve. However, our current knowledge of protein function likely represents a small fraction of the diverse repertoire that exists in nature. Integrative computational methods can facilitate the discovery of new protein functions and enzymatic reactions through the observation and investigation of the complex sequence-structure-function relationships within protein superfamilies. Here, we highlight the use of sequence similarity networks (SSNs) to identify previously unexplored sequence and function space. We exemplify this approach using the nitroreductase (NTR) superfamily. We demonstrate that SSN investigations can provide a rapid and effective means to classify groups of proteins, therefore exposing experimentally unexplored sequences that may exhibit novel functionality. Integration of such approaches with systematic experimental characterization will expand our understanding of the functional diversity of enzymes and their associated physiological roles.
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Affiliation(s)
- Janine N Copp
- Michael Smith Laboratories , University of British Columbia , 2185 East Mall , Vancouver , British Columbia V6T 1Z4 , Canada
| | - Eyal Akiva
- Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , California 94158 , United States.,Quantitative Biosciences Institute , University of California , San Francisco , California 94143 , United States
| | - Patricia C Babbitt
- Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , California 94158 , United States.,Quantitative Biosciences Institute , University of California , San Francisco , California 94143 , United States
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories , University of British Columbia , 2185 East Mall , Vancouver , British Columbia V6T 1Z4 , Canada
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36
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Oxidative Phosphorylation as a Target Space for Tuberculosis: Success, Caution, and Future Directions. Microbiol Spectr 2017; 5. [PMID: 28597820 DOI: 10.1128/microbiolspec.tbtb2-0014-2016] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The emergence and spread of drug-resistant pathogens, and our inability to develop new antimicrobials to combat resistance, have inspired scientists to seek out new targets for drug development. The Mycobacterium tuberculosis complex is a group of obligately aerobic bacteria that have specialized for inhabiting a wide range of intracellular and extracellular environments. Two fundamental features in this adaptation are the flexible utilization of energy sources and continued metabolism in the absence of growth. M. tuberculosis is an obligately aerobic heterotroph that depends on oxidative phosphorylation for growth and survival. However, several studies are redefining the metabolic breadth of the genus. Alternative electron donors and acceptors may provide the maintenance energy for the pathogen to maintain viability in hypoxic, nonreplicating states relevant to latent infection. This hidden metabolic flexibility may ultimately decrease the efficacy of drugs targeted against primary dehydrogenases and terminal oxidases. However, it may also open up opportunities to develop novel antimycobacterials targeting persister cells. In this review, we discuss the progress in understanding the role of energetic targets in mycobacterial physiology and pathogenesis and the opportunities for drug discovery.
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37
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Evolutionary and molecular foundations of multiple contemporary functions of the nitroreductase superfamily. Proc Natl Acad Sci U S A 2017; 114:E9549-E9558. [PMID: 29078300 PMCID: PMC5692541 DOI: 10.1073/pnas.1706849114] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Functionally diverse enzyme superfamilies are sets of homologs that conserve a structural fold and mechanistic details but perform various distinct chemical reactions. What are the evolutionary routes by which ancestral proteins diverge to produce extant enzymes? We present an approach that combines experimental data with computational tools to trace these sequence–structure–function transitions in a model system, the functionally diverse flavin mononucleotide-dependent nitroreductases (NTRs). Our results suggest an evolutionary model in which contemporary NTR classes have diverged in a radial manner from a minimal flavin-binding scaffold via insertions at key positions and fixation of functional residues, yielding the reaction versatility of contemporary enzymes. These principles will facilitate rational design of NTRs and advance general approaches for delineating the emergence of functional diversity in enzyme superfamilies. Insight regarding how diverse enzymatic functions and reactions have evolved from ancestral scaffolds is fundamental to understanding chemical and evolutionary biology, and for the exploitation of enzymes for biotechnology. We undertook an extensive computational analysis using a unique and comprehensive combination of tools that include large-scale phylogenetic reconstruction to determine the sequence, structural, and functional relationships of the functionally diverse flavin mononucleotide-dependent nitroreductase (NTR) superfamily (>24,000 sequences from all domains of life, 54 structures, and >10 enzymatic functions). Our results suggest an evolutionary model in which contemporary subgroups of the superfamily have diverged in a radial manner from a minimal flavin-binding scaffold. We identified the structural design principle for this divergence: Insertions at key positions in the minimal scaffold that, combined with the fixation of key residues, have led to functional specialization. These results will aid future efforts to delineate the emergence of functional diversity in enzyme superfamilies, provide clues for functional inference for superfamily members of unknown function, and facilitate rational redesign of the NTR scaffold.
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38
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Hopkins DH, Fraser NJ, Mabbitt PD, Carr PD, Oakeshott JG, Jackson CJ. Structure of an Insecticide Sequestering Carboxylesterase from the Disease Vector Culex quinquefasciatus: What Makes an Enzyme a Good Insecticide Sponge? Biochemistry 2017; 56:5512-5525. [DOI: 10.1021/acs.biochem.7b00774] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Davis H. Hopkins
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Nicholas J. Fraser
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Peter D. Mabbitt
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Paul D. Carr
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - John G. Oakeshott
- CSIRO, GPO
Box 1700, Canberra, Australian Capital Territory 2601, Australia
| | - Colin J. Jackson
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 0200, Australia
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39
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Ney B, Carere CR, Sparling R, Jirapanjawat T, Stott MB, Jackson CJ, Oakeshott JG, Warden AC, Greening C. Cofactor Tail Length Modulates Catalysis of Bacterial F 420-Dependent Oxidoreductases. Front Microbiol 2017; 8:1902. [PMID: 29021791 PMCID: PMC5623714 DOI: 10.3389/fmicb.2017.01902] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 09/15/2017] [Indexed: 11/13/2022] Open
Abstract
F420 is a microbial cofactor that mediates a wide range of physiologically important and industrially relevant redox reactions, including in methanogenesis and tetracycline biosynthesis. This deazaflavin comprises a redox-active isoalloxazine headgroup conjugated to a lactyloligoglutamyl tail. Here we studied the catalytic significance of the oligoglutamate chain, which differs in length between bacteria and archaea. We purified short-chain F420 (two glutamates) from a methanogen isolate and long-chain F420 (five to eight glutamates) from a recombinant mycobacterium, confirming their different chain lengths by HPLC and LC/MS analysis. F420 purified from both sources was catalytically compatible with purified enzymes from the three major bacterial families of F420-dependent oxidoreductases. However, long-chain F420 bound to these enzymes with a six- to ten-fold higher affinity than short-chain F420. The cofactor side chain also significantly modulated the kinetics of the enzymes, with long-chain F420 increasing the substrate affinity (lower Km) but reducing the turnover rate (lower kcat) of the enzymes. Molecular dynamics simulations and comparative structural analysis suggest that the oligoglutamate chain of F420 makes dynamic electrostatic interactions with conserved surface residues of the oxidoreductases while the headgroup binds the catalytic site. In conjunction with the kinetic data, this suggests that electrostatic interactions made by the oligoglutamate tail result in higher-affinity, lower-turnover catalysis. Physiologically, we propose that bacteria have selected for long-chain F420 to better control cellular redox reactions despite tradeoffs in catalytic rate. Conversely, this suggests that industrial use of shorter-length F420 will greatly increase the rates of bioremediation and biocatalysis processes relying on purified F420-dependent oxidoreductases.
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Affiliation(s)
- Blair Ney
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.,Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, Acton, ACT, Australia
| | - Carlo R Carere
- GNS Science, Wairakei Research Centre, Lower Hutt, New Zealand
| | - Richard Sparling
- GNS Science, Wairakei Research Centre, Lower Hutt, New Zealand.,Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | | | - Matthew B Stott
- GNS Science, Wairakei Research Centre, Lower Hutt, New Zealand
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Acton, ACT, Australia
| | - John G Oakeshott
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, Acton, ACT, Australia
| | - Andrew C Warden
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, Acton, ACT, Australia
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.,Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, Acton, ACT, Australia
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40
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Greening C, Jirapanjawat T, Afroze S, Ney B, Scott C, Pandey G, Lee BM, Russell RJ, Jackson CJ, Oakeshott JG, Taylor MC, Warden AC. Mycobacterial F 420H 2-Dependent Reductases Promiscuously Reduce Diverse Compounds through a Common Mechanism. Front Microbiol 2017; 8:1000. [PMID: 28620367 PMCID: PMC5449967 DOI: 10.3389/fmicb.2017.01000] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/18/2017] [Indexed: 01/24/2023] Open
Abstract
An unusual aspect of actinobacterial metabolism is the use of the redox cofactor F420. Studies have shown that actinobacterial F420H2-dependent reductases promiscuously hydrogenate diverse organic compounds in biodegradative and biosynthetic processes. These enzymes therefore represent promising candidates for next-generation industrial biocatalysts. In this work, we undertook the first broad survey of these enzymes as potential industrial biocatalysts by exploring the extent, as well as mechanistic and structural bases, of their substrate promiscuity. We expressed and purified 11 enzymes from seven subgroups of the flavin/deazaflavin oxidoreductase (FDOR) superfamily (A1, A2, A3, B1, B2, B3, B4) from the model soil actinobacterium Mycobacterium smegmatis. These enzymes reduced compounds from six chemical classes, including fundamental monocycles such as a cyclohexenone, a dihydropyran, and pyrones, as well as more complex quinone, coumarin, and arylmethane compounds. Substrate range and reduction rates varied between the enzymes, with the A1, A3, and B1 groups exhibiting greatest promiscuity. Molecular docking studies suggested that structurally diverse compounds are accommodated in the large substrate-binding pocket of the most promiscuous FDOR through hydrophobic interactions with conserved aromatic residues and the isoalloxazine headgroup of F420H2. Liquid chromatography-mass spectrometry (LC/MS) and gas chromatography-mass spectrometry (GC/MS) analysis of derivatized reaction products showed reduction occurred through a common mechanism involving hydride transfer from F420H- to the electron-deficient alkene groups of substrates. Reduction occurs when the hydride donor (C5 of F420H-) is proximal to the acceptor (electrophilic alkene of the substrate). These findings suggest that engineered actinobacterial F420H2-dependent reductases are promising novel biocatalysts for the facile transformation of a wide range of α,β-unsaturated compounds.
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Affiliation(s)
- Chris Greening
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia.,School of Biological Sciences, Monash University, ClaytonVIC, Australia
| | - Thanavit Jirapanjawat
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia.,School of Biological Sciences, Monash University, ClaytonVIC, Australia.,Research School of Chemistry, Australian National University, ActonACT, Australia
| | - Shahana Afroze
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia.,Research School of Chemistry, Australian National University, ActonACT, Australia
| | - Blair Ney
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia.,School of Biological Sciences, Monash University, ClaytonVIC, Australia.,Research School of Chemistry, Australian National University, ActonACT, Australia
| | - Colin Scott
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
| | - Gunjan Pandey
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
| | - Brendon M Lee
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia.,Research School of Chemistry, Australian National University, ActonACT, Australia
| | - Robyn J Russell
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, ActonACT, Australia
| | - John G Oakeshott
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
| | - Matthew C Taylor
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
| | - Andrew C Warden
- Land and Water Flagship, The Commonwealth Scientific and Industrial Research Organisation, ActonACT, Australia
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41
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Chu WT, Nesbitt NM, Gnatenko DV, Li Z, Zhang B, Seeliger MA, Browne S, Mantle TJ, Bahou WF, Wang J. Enzymatic Activity and Thermodynamic Stability of Biliverdin IXβ Reductase Are Maintained by an Active Site Serine. Chemistry 2017; 23:1891-1900. [PMID: 27897348 DOI: 10.1002/chem.201604517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Indexed: 11/10/2022]
Abstract
Biliverdin reductase IXβ (BLVRB) is a crucial enzyme in heme metabolism. Recent studies in humans have identified a loss-of-function mutation (Ser111Leu) that unmasks a fundamentally important role in hematopoiesis. We have undertaken experimental and thermodynamic modeling studies to provide further insight into the role of the cofactor in substrate accessibility and protein folding properties regulating BLVRB catalytic mechanisms. Site-directed mutagenesis with molecular dynamic (MD) simulations establish the critical role of NAD(P)H-dependent conformational changes on substrate accessibility by forming the "hydrophobic pocket", along with identification of a single key residue (Arg35) modulating NADPH/NADH selectivity. Loop80 and Loop120 block the hydrophobic substrate binding pocket in apo BLVRB (open), whereas movement of these structures after cofactor binding results in the "closed" (catalytically active) conformation. Both enzymatic activity and thermodynamic stability are affected by mutation(s) involving Ser111, which is located in the core of the BLVRB active site. This work 1) elucidates the crucial role of Ser111 in enzymatic catalysis and thermodynamic stability by active site hydrogen bond network; 2) defines a dynamic model for apo BLVRB extending beyond the crystal structure of the binary BLVRB/NADP+ complex; 3) provides a structural basis for the "encounter" and "equilibrium" states of the binary complex, which are regulated by NAD(P)H.
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Affiliation(s)
- Wen-Ting Chu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
| | - Natasha M Nesbitt
- Department of Medicine, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Dmitri V Gnatenko
- Department of Medicine, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Zongdong Li
- Department of Medicine, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Beibei Zhang
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Markus A Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Seamus Browne
- Department of Biochemistry, Trinity College, Dublin 2, Ireland
| | | | - Wadie F Bahou
- Department of Medicine, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Jin Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.,Department of Chemistry and Physics, Stony Brook University, Stony Brook, NY, 11794, USA
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42
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Discovery and characterization of an F 420-dependent glucose-6-phosphate dehydrogenase (Rh-FGD1) from Rhodococcus jostii RHA1. Appl Microbiol Biotechnol 2016; 101:2831-2842. [PMID: 27966048 PMCID: PMC5352752 DOI: 10.1007/s00253-016-8038-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/22/2016] [Accepted: 11/26/2016] [Indexed: 12/16/2022]
Abstract
Cofactor F420, a 5-deazaflavin involved in obligatory hydride transfer, is widely distributed among archaeal methanogens and actinomycetes. Owing to the low redox potential of the cofactor, F420-dependent enzymes play a pivotal role in central catabolic pathways and xenobiotic degradation processes in these organisms. A physiologically essential deazaflavoenzyme is the F420-dependent glucose-6-phosphate dehydrogenase (FGD), which catalyzes the reaction F420 + glucose-6-phosphate → F420H2 + 6-phospho-gluconolactone. Thereby, FGDs generate the reduced F420 cofactor required for numerous F420H2-dependent reductases, involved e.g., in the bioreductive activation of the antitubercular prodrugs pretomanid and delamanid. We report here the identification, production, and characterization of three FGDs from Rhodococcus jostii RHA1 (Rh-FGDs), being the first experimental evidence of F420-dependent enzymes in this bacterium. The crystal structure of Rh-FGD1 has also been determined at 1.5 Å resolution, showing a high similarity with FGD from Mycobacterium tuberculosis (Mtb) (Mtb-FGD1). The cofactor-binding pocket and active-site catalytic residues are largely conserved in Rh-FGD1 compared with Mtb-FGD1, except for an extremely flexible insertion region capping the active site at the C-terminal end of the TIM-barrel, which also markedly differs from other structurally related proteins. The role of the three positively charged residues (Lys197, Lys258, and Arg282) constituting the binding site of the substrate phosphate moiety was experimentally corroborated by means of mutagenesis study. The biochemical and structural data presented here provide the first step towards tailoring Rh-FGD1 into a more economical biocatalyst, e.g., an F420-dependent glucose dehydrogenase that requires a cheaper cosubstrate and can better match the demands for the growing applications of F420H2-dependent reductases in industry and bioremediation.
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43
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Mohamed AE, Condic-Jurkic K, Ahmed FH, Yuan P, O'Mara ML, Jackson CJ, Coote ML. Hydrophobic Shielding Drives Catalysis of Hydride Transfer in a Family of F 420H 2-Dependent Enzymes. Biochemistry 2016; 55:6908-6918. [PMID: 27951661 DOI: 10.1021/acs.biochem.6b00683] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A family of flavin/deazaflavin-dependent oxidoreductases (FDORs) from mycobacteria has been recently characterized and found to play a variety of catalytic roles, including the activation of prodrugs such as the candidate anti-tuberculosis drug pretomanid (PA-824). However, our understanding of the catalytic mechanism used by these enzymes is relatively limited. To address this, we have used a combination of quantum mechanics and molecular dynamics calculations to study the catalytic mechanism of the activation of pretomanid by the deazaflavin-dependent nitroreductase (Ddn) from Mycobacterium tuberculosis. The preferred pathway involves an initial hydride transfer step from the deprotonated cofactor (i.e., F420H-), with subsequent protonation, before a series of spontaneous intramolecular reactions to form the final reactive nitrogen species. The most likely proton source is a hydroxonium ion within the solvent accessible active site. Intriguingly, catalysis of the rate-determining hydride transfer step is aided by three tyrosine residues that form a hydrophobic barrier around the active site that, upon reaction, is then disrupted to allow increased water accessibility to facilitate the subsequent proton transfer step. The catalytic mechanism we propose is consistent with previous experimental observations of the Ddn enzyme and will inform the design of improved prodrugs in the future.
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Affiliation(s)
- A Elaaf Mohamed
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - Karmen Condic-Jurkic
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - F Hafna Ahmed
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - Peng Yuan
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - Megan L O'Mara
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
| | - Michelle L Coote
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University , Canberra, ACT 2601, Australia
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44
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Baier F, Copp JN, Tokuriki N. Evolution of Enzyme Superfamilies: Comprehensive Exploration of Sequence–Function Relationships. Biochemistry 2016; 55:6375-6388. [DOI: 10.1021/acs.biochem.6b00723] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F. Baier
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - J. N. Copp
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - N. Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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45
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Søndergaard D, Pedersen CNS, Greening C. HydDB: A web tool for hydrogenase classification and analysis. Sci Rep 2016; 6:34212. [PMID: 27670643 PMCID: PMC5037454 DOI: 10.1038/srep34212] [Citation(s) in RCA: 290] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/09/2016] [Indexed: 01/22/2023] Open
Abstract
H2 metabolism is proposed to be the most ancient and diverse mechanism of energy-conservation. The metalloenzymes mediating this metabolism, hydrogenases, are encoded by over 60 microbial phyla and are present in all major ecosystems. We developed a classification system and web tool, HydDB, for the structural and functional analysis of these enzymes. We show that hydrogenase function can be predicted by primary sequence alone using an expanded classification scheme (comprising 29 [NiFe], 8 [FeFe], and 1 [Fe] hydrogenase classes) that defines 11 new classes with distinct biological functions. Using this scheme, we built a web tool that rapidly and reliably classifies hydrogenase primary sequences using a combination of k-nearest neighbors' algorithms and CDD referencing. Demonstrating its capacity, the tool reliably predicted hydrogenase content and function in 12 newly-sequenced bacteria, archaea, and eukaryotes. HydDB provides the capacity to browse the amino acid sequences of 3248 annotated hydrogenase catalytic subunits and also contains a detailed repository of physiological, biochemical, and structural information about the 38 hydrogenase classes defined here. The database and classifier are freely and publicly available at http://services.birc.au.dk/hyddb/.
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Affiliation(s)
- Dan Søndergaard
- Aarhus University, Bioinformatics Research Centre, C.F. Møllers Allé 8, Aarhus DK-8000, Denmark
| | | | - Chris Greening
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship, Clunies Ross Street, Acton, ACT 2601, Australia
- Monash University, School of Biological Sciences, Clayton, VIC 3800, Australia
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46
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The Redox Cofactor F 420 Protects Mycobacteria from Diverse Antimicrobial Compounds and Mediates a Reductive Detoxification System. Appl Environ Microbiol 2016; 82:6810-6818. [PMID: 27637879 DOI: 10.1128/aem.02500-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/06/2016] [Indexed: 01/25/2023] Open
Abstract
A defining feature of mycobacterial redox metabolism is the use of an unusual deazaflavin cofactor, F420 This cofactor enhances the persistence of environmental and pathogenic mycobacteria, including after antimicrobial treatment, although the molecular basis for this remains to be understood. In this work, we explored our hypothesis that F420 enhances persistence by serving as a cofactor in antimicrobial-detoxifying enzymes. To test this, we performed a series of phenotypic, biochemical, and analytical chemistry studies in relation to the model soil bacterium Mycobacterium smegmatis Mutant strains unable to synthesize or reduce F420 were found to be more susceptible to a wide range of antibiotic and xenobiotic compounds. Compounds from three classes of antimicrobial compounds traditionally resisted by mycobacteria inhibited the growth of F420 mutant strains at subnanomolar concentrations, namely, furanocoumarins (e.g., methoxsalen), arylmethanes (e.g., malachite green), and quinone analogues (e.g., menadione). We demonstrated that promiscuous F420H2-dependent reductases directly reduce these compounds by a mechanism consistent with hydride transfer. Moreover, M. smegmatis strains unable to make F420H2 lost the capacity to reduce and detoxify representatives of the furanocoumarin and arylmethane compound classes in whole-cell assays. In contrast, mutant strains were only slightly more susceptible to clinical antimycobacterials, and this appeared to be due to indirect effects of F420 loss of function (e.g., redox imbalance) rather than loss of a detoxification system. Together, these data show that F420 enhances antimicrobial resistance in mycobacteria and suggest that one function of the F420H2-dependent reductases is to broaden the range of natural products that mycobacteria and possibly other environmental actinobacteria can reductively detoxify.IMPORTANCE This study reveals that a unique microbial cofactor, F420, is critical for antimicrobial resistance in the environmental actinobacterium Mycobacterium smegmatis We show that a superfamily of redox enzymes, the F420H2-dependent reductases, can reduce diverse antimicrobials in vitro and in vivoM. smegmatis strains unable to make or reduce F420 become sensitive to inhibition by these antimicrobial compounds. This suggests that mycobacteria have harnessed the unique properties of F420 to reduce structurally diverse antimicrobials as part of the antibiotic arms race. The F420H2-dependent reductases that facilitate this process represent a new class of antimicrobial-detoxifying enzymes with potential applications in bioremediation and biocatalysis.
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47
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Li D, Moorman R, Vanhercke T, Petrie J, Singh S, Jackson CJ. Classification and substrate head-group specificity of membrane fatty acid desaturases. Comput Struct Biotechnol J 2016; 14:341-349. [PMID: 27708750 PMCID: PMC5037126 DOI: 10.1016/j.csbj.2016.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 01/22/2023] Open
Abstract
Membrane fatty acid desaturases are a diverse superfamily of enzymes that catalyze the introduction of double bonds into fatty acids. They are essential in a range of metabolic processes, such as the production of omega-3 fatty acids. However, our structure-function understanding of this superfamily is still developing and their range of activities and substrate specificities are broad, and often overlapping, which has made their systematic characterization challenging. A central issue with characterizing these proteins has been the lack of a structural model, which has been overcome with the recent publication of the crystal structures of two mammalian fatty acid desaturases. In this work, we have used sequence similarity networks to investigate the similarity among over 5000 related membrane fatty acid desaturase sequences, leading to a detailed classification of the superfamily, families and subfamilies with regard to their function and substrate head-group specificity. This work will facilitate rapid prediction of the function and specificity of new and existing sequences, as well as forming a basis for future efforts to manipulate the substrate specificity of these proteins for biotechnology applications.
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Affiliation(s)
- Dongdi Li
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Ruth Moorman
- Research School of Chemistry, Australian National University, Canberra, Australia
| | | | | | | | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, Australia
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48
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Ney B, Ahmed FH, Carere CR, Biswas A, Warden AC, Morales SE, Pandey G, Watt SJ, Oakeshott JG, Taylor MC, Stott MB, Jackson CJ, Greening C. The methanogenic redox cofactor F 420 is widely synthesized by aerobic soil bacteria. ISME JOURNAL 2016; 11:125-137. [PMID: 27505347 DOI: 10.1038/ismej.2016.100] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/07/2016] [Accepted: 06/13/2016] [Indexed: 02/07/2023]
Abstract
F420 is a low-potential redox cofactor that mediates the transformations of a wide range of complex organic compounds. Considered one of the rarest cofactors in biology, F420 is best known for its role in methanogenesis and has only been chemically identified in two phyla to date, the Euryarchaeota and Actinobacteria. In this work, we show that this cofactor is more widely distributed than previously reported. We detected the genes encoding all five known F420 biosynthesis enzymes (cofC, cofD, cofE, cofG and cofH) in at least 653 bacterial and 173 archaeal species, including members of the dominant soil phyla Proteobacteria, Chloroflexi and Firmicutes. Metagenome datamining validated that these genes were disproportionately abundant in aerated soils compared with other ecosystems. We confirmed through high-performance liquid chromatography analysis that aerobically grown stationary-phase cultures of three bacterial species, Paracoccus denitrificans, Oligotropha carboxidovorans and Thermomicrobium roseum, synthesized F420, with oligoglutamate sidechains of different lengths. To understand the evolution of F420 biosynthesis, we also analyzed the distribution, phylogeny and genetic organization of the cof genes. Our data suggest that although the Fo precursor to F420 originated in methanogens, F420 itself was first synthesized in an ancestral actinobacterium. F420 biosynthesis genes were then disseminated horizontally to archaea and other bacteria. Together, our findings suggest that the cofactor is more significant in aerobic bacterial metabolism and soil ecosystem composition than previously thought. The cofactor may confer several competitive advantages for aerobic soil bacteria by mediating their central metabolic processes and broadening the range of organic compounds they can synthesize, detoxify and mineralize.
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Affiliation(s)
- Blair Ney
- Research School of Chemistry, Australian National University, Acton, Australian Capital Territory, Australia.,The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
| | - F Hafna Ahmed
- Research School of Chemistry, Australian National University, Acton, Australian Capital Territory, Australia
| | - Carlo R Carere
- GNS Science, Wairakei Research Centre, Taupō, New Zealand
| | - Ambarish Biswas
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Andrew C Warden
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
| | - Sergio E Morales
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Gunjan Pandey
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
| | - Stephen J Watt
- Research School of Chemistry, Australian National University, Acton, Australian Capital Territory, Australia
| | - John G Oakeshott
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
| | - Matthew C Taylor
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
| | | | - Colin J Jackson
- Research School of Chemistry, Australian National University, Acton, Australian Capital Territory, Australia
| | - Chris Greening
- The Commonwealth Scientific and Industrial Research Organisation, Land and Water, Acton, Australian Capital Territory, Australia
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49
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Ahmed FH, Mohamed AE, Carr PD, Lee BM, Condic-Jurkic K, O'Mara ML, Jackson CJ. Rv2074 is a novel F420 H2 -dependent biliverdin reductase in Mycobacterium tuberculosis. Protein Sci 2016; 25:1692-709. [PMID: 27364382 DOI: 10.1002/pro.2975] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/29/2016] [Indexed: 12/12/2022]
Abstract
Bilirubin is a potent antioxidant that is produced from the reduction of the heme degradation product biliverdin. In mammalian cells and Cyanobacteria, NADH/NADPH-dependent biliverdin reductases (BVRs) of the Rossmann-fold have been shown to catalyze this reaction. Here, we describe the characterization of Rv2074 from Mycobacterium tuberculosis, which belongs to a structurally and mechanistically distinct family of F420 H2 -dependent BVRs (F-BVRs) that are exclusively found in Actinobacteria. We have solved the crystal structure of Rv2074 bound to its cofactor, F420 , and used this alongside molecular dynamics simulations, site-directed mutagenesis and NMR spectroscopy to elucidate its catalytic mechanism. The production of bilirubin by Rv2074 could exploit the anti-oxidative properties of bilirubin and contribute to the range of immuno-evasive mechanisms that have evolved in M. tuberculosis to allow persistent infection.
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Affiliation(s)
- F Hafna Ahmed
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - A Elaaf Mohamed
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Paul D Carr
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Brendon M Lee
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Karmen Condic-Jurkic
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Megan L O'Mara
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
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50
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Mascotti ML, Juri Ayub M, Furnham N, Thornton JM, Laskowski RA. Chopping and Changing: the Evolution of the Flavin-dependent Monooxygenases. J Mol Biol 2016; 428:3131-46. [PMID: 27423402 PMCID: PMC4981433 DOI: 10.1016/j.jmb.2016.07.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/24/2016] [Accepted: 07/05/2016] [Indexed: 12/21/2022]
Abstract
Flavin-dependent monooxygenases play a variety of key physiological roles and are also very powerful biotechnological tools. These enzymes have been classified into eight different classes (A–H) based on their sequences and biochemical features. By combining structural and sequence analysis, and phylogenetic inference, we have explored the evolutionary history of classes A, B, E, F, and G and demonstrate that their multidomain architectures reflect their phylogenetic relationships, suggesting that the main evolutionary steps in their divergence are likely to have arisen from the recruitment of different domains. Additionally, the functional divergence within in each class appears to have been the result of other mechanisms such as a complex set of single-point mutations. Our results reinforce the idea that a main constraint on the evolution of cofactor-dependent enzymes is the functional binding of the cofactor. Additionally, a remarkable feature of this family is that the sequence of the key flavin adenine dinucleotide-binding domain is split into at least two parts in all classes studied here. We propose a complex set of evolutionary events that gave rise to the origin of the different classes within this family. Changes in domain architectures reflect the phylogeny of flavin monooxygenases. Recruitment of different domains has been the main force driving its evolution. A notable feature of flavin monooxygenases is that the flavin adenine dinucleotide-binding domain is split. Classes of monooxygenases emerged from an ancestral domain by structural changes.
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Affiliation(s)
- Maria Laura Mascotti
- IMIBIO-SL CONICET, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de los Andes 950, San Luis D5700HHW, Argentina.
| | - Maximiliano Juri Ayub
- IMIBIO-SL CONICET, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de los Andes 950, San Luis D5700HHW, Argentina
| | - Nicholas Furnham
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Janet M Thornton
- EMBL-EBI, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Roman A Laskowski
- EMBL-EBI, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK.
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