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Leo G, Leone P, Ataie Kachoie E, Tolomeo M, Galluccio M, Indiveri C, Barile M, Capaldi S. Structural insights into the bifunctional enzyme human FAD synthase. Structure 2024:S0969-2126(24)00132-1. [PMID: 38688286 DOI: 10.1016/j.str.2024.04.006] [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: 02/08/2024] [Revised: 03/20/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024]
Abstract
Human flavin adenine dinucleotide synthase (hFADS) is a bifunctional, multi-domain enzyme that exhibits both flavin mononucleotide adenylyltransferase and pyrophosphatase activities. Here we report the crystal structure of full-length hFADS2 and its C-terminal PAPS domain in complex with flavin adenine dinucleotide (FAD), and dissect the structural determinants underlying the contribution of each individual domain, within isoforms 1 and 2, to each of the two enzymatic activities. Structural and functional characterization performed on complete or truncated constructs confirmed that the C-terminal domain tightly binds FAD and catalyzes its synthesis, while the combination of the N-terminal molybdopterin-binding and KH domains is the minimal essential substructure required for the hydrolysis of FAD and other ADP-containing dinucleotides. hFADS2 associates in a stable C2-symmetric dimer, in which the packing of the KH domain of one protomer against the N-terminal domain of the other creates the adenosine-specific active site responsible for the hydrolytic activity.
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Affiliation(s)
- Giulia Leo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Piero Leone
- Department of Biosciences, Biotechnology and Environment, University of Bari, via Orabona 4, 70126 Bari, Italy
| | - Elham Ataie Kachoie
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Maria Tolomeo
- Department of Biosciences, Biotechnology and Environment, University of Bari, via Orabona 4, 70126 Bari, Italy; Department of Biology, Ecology and Earth Sciences (DiBEST), Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, via P. Bucci 4c, 6c, 87036 Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department of Biology, Ecology and Earth Sciences (DiBEST), Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, via P. Bucci 4c, 6c, 87036 Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department of Biology, Ecology and Earth Sciences (DiBEST), Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, via P. Bucci 4c, 6c, 87036 Arcavacata di Rende, Italy; National Research Council (CNR), Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), via Amendola 122/O, 70126 Bari, Italy
| | - Maria Barile
- Department of Biosciences, Biotechnology and Environment, University of Bari, via Orabona 4, 70126 Bari, Italy.
| | - Stefano Capaldi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
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2
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Sharma A, Bansal S, Kumari N, Vashistt J, Shrivastava R. Comparative proteomic investigation unravels the pathobiology of Mycobacterium fortuitum biofilm. Appl Microbiol Biotechnol 2023; 107:6029-6046. [PMID: 37542577 DOI: 10.1007/s00253-023-12705-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/26/2023] [Accepted: 07/15/2023] [Indexed: 08/07/2023]
Abstract
Biofilm formation by Mycobacterium fortuitum causes serious threats to human health due to its increased contribution to nosocomial infections. In this study, the first comprehensive global proteome analysis of M. fortuitum was reported under planktonic and biofilm growth states. A label-free Q Exactive Quadrupole-Orbitrap tandem mass spectrometry analysis was performed on the protein lysates. The differentially abundant proteins were functionally characterized and re-annotated using Blast2GO and CELLO2GO. Comparative analysis of the proteins among two growth states provided insights into the phenotypic switch, and fundamental pathways associated with pathobiology of M. fortuitum biofilm, such as lipid biosynthesis and quorum-sensing. Interaction network generated by the STRING database revealed associations between proteins that endure M. fortuitum during biofilm growth state. Hypothetical proteins were also studied to determine their functional alliance with the biofilm phenotype. CARD, VFDB, and PATRIC analysis further showed that the proteins upregulated in M. fortuitum biofilm exhibited antibiotic resistance, pathogenesis, and virulence. Heatmap and correlation analysis provided the biomarkers associated with the planktonic and biofilm growth of M. fortuitum. Proteome data was validated by qPCR analysis. Overall, the study provides insights into previously unexplored biochemical pathways that can be targeted by novel inhibitors, either for shortened treatment duration or for eliminating biofilm of M. fortuitum and related nontuberculous mycobacterial pathogens. KEY POINTS: • Proteomic analyses of M. fortuitum reveals novel biofilm markers. • Acetyl-CoA acetyltransferase acts as the phenotype transition switch. • The study offers drug targets to combat M. fortuitum biofilm infections.
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Affiliation(s)
- Ayushi Sharma
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Saurabh Bansal
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Neha Kumari
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Jitendraa Vashistt
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India
| | - Rahul Shrivastava
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, 173234, H.P, India.
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3
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Lynch JH, Roje S. A higher plant FAD synthetase is fused to an inactivated FAD pyrophosphatase. J Biol Chem 2022; 298:102626. [PMID: 36273586 PMCID: PMC9678776 DOI: 10.1016/j.jbc.2022.102626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022] Open
Abstract
The riboflavin derivatives FMN and flavin adenine dinucleotide (FAD) are critical cofactors for wide-ranging biological processes across all kingdoms of life. Although it is well established that these flavins can be readily interconverted, in plants, the responsible catalysts and regulatory mechanisms remain poorly understood. Here, we report the cloning and biochemical characterization of an FAD synthetase encoded by the gene At5g03430, which we have designated AtFADS1 (A. thaliana FADS1). The catalytic properties of the FAD synthetase activity are similar to those reported for other FAD synthetases, except that we observed maximum activity with Zn2+ as the associated divalent metal cation. Like human FAD synthetase, AtFADS1 exists as an apparent fusion with an ancestral FAD pyrophosphatase, a feature that is conserved across plants. However, we detected no pyrophosphatase activity with AtFADS1, consistent with an observed loss of a key catalytic residue in higher plant evolutionary history. In contrast, we determined that algal FADS1 retains both FAD synthetase and pyrophosphatase activity. We discuss the implications, including the potential for yet-unstudied biologically relevant noncatalytic functions, and possible evolutionary pressures that have led to the loss of FAD pyrophosphatase activity, yet universal retention of an apparently nonfunctional domain in FADS of land plants.
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Affiliation(s)
- Joseph H Lynch
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - Sanja Roje
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA.
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4
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Kreutzfeldt KM, Jansen RS, Hartman TE, Gouzy A, Wang R, Krieger IV, Zimmerman MD, Gengenbacher M, Sarathy JP, Xie M, Dartois V, Sacchettini JC, Rhee KY, Schnappinger D, Ehrt S. CinA mediates multidrug tolerance in Mycobacterium tuberculosis. Nat Commun 2022; 13:2203. [PMID: 35459278 PMCID: PMC9033802 DOI: 10.1038/s41467-022-29832-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/31/2022] [Indexed: 12/23/2022] Open
Abstract
The ability of Mycobacterium tuberculosis (Mtb) to resist and tolerate antibiotics complicates the development of improved tuberculosis (TB) chemotherapies. Here we define the Mtb protein CinA as a major determinant of drug tolerance and as a potential target to shorten TB chemotherapy. By reducing the fraction of drug-tolerant persisters, genetic inactivation of cinA accelerated killing of Mtb by four antibiotics in clinical use: isoniazid, ethionamide, delamanid and pretomanid. Mtb ΔcinA was killed rapidly in conditions known to impede the efficacy of isoniazid, such as during nutrient starvation, during persistence in a caseum mimetic, in activated macrophages and during chronic mouse infection. Deletion of CinA also increased in vivo killing of Mtb by BPaL, a combination of pretomanid, bedaquiline and linezolid that is used to treat highly drug-resistant TB. Genetic and drug metabolism studies suggest that CinA mediates drug tolerance via cleavage of NAD-drug adducts.
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Affiliation(s)
- Kaj M Kreutzfeldt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Robert S Jansen
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical College, New York, NY, 10065, USA
- Department of Microbiology, Radboud University, 6525 AJ, Nijmegen, The Netherlands
| | - Travis E Hartman
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Alexandre Gouzy
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Ruojun Wang
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08540, USA
| | - Inna V Krieger
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Matthew D Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Martin Gengenbacher
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Jansy P Sarathy
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Min Xie
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Véronique Dartois
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - James C Sacchettini
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Kyu Y Rhee
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medical College, New York, NY, 10065, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA.
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA.
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Cameranesi MM, Paganini J, Limansky AS, Moran-Barrio J, Salcedo SP, Viale AM, Repizo GD. Acquisition of plasmids conferring carbapenem and aminoglycoside resistance and loss of surface-exposed macromolecule structures as strategies for the adaptation of Acinetobacter baumannii CC104 O/CC15 P strains to the clinical setting. Microb Genom 2020; 6. [PMID: 32213259 PMCID: PMC7643966 DOI: 10.1099/mgen.0.000360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii (Aba) is an emerging opportunistic pathogen associated to nosocomial infections. The rapid increase in multidrug resistance (MDR) among Aba strains underscores the urgency of understanding how this pathogen evolves in the clinical environment. We conducted here a whole-genome sequence comparative analysis of three phylogenetically and epidemiologically related MDR Aba strains from Argentinean hospitals, assigned to the CC104O/CC15P clonal complex. While the Ab244 strain was carbapenem-susceptible, Ab242 and Ab825, isolated after the introduction of carbapenem therapy, displayed resistance to these last resource β-lactams. We found a high chromosomal synteny among the three strains, but significant differences at their accessory genomes. Most importantly, carbapenem resistance in Ab242 and Ab825 was attributed to the acquisition of a Rep_3 family plasmid carrying a blaOXA-58 gene. Other differences involved a genomic island carrying resistance to toxic compounds and a Tn10 element exclusive to Ab244 and Ab825, respectively. Also remarkably, 44 insertion sequences (ISs) were uncovered in Ab825, in contrast with the 14 and 11 detected in Ab242 and Ab244, respectively. Moreover, Ab825 showed a higher killing capacity as compared to the other two strains in the Galleria mellonella infection model. A search for virulence and persistence determinants indicated the loss or IS-mediated interruption of genes encoding many surface-exposed macromolecules in Ab825, suggesting that these events are responsible for its higher relative virulence. The comparative genomic analyses of the CC104O/CC15P strains conducted here revealed the contribution of acquired mobile genetic elements such as ISs and plasmids to the adaptation of A. baumannii to the clinical setting.
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Affiliation(s)
- María M Cameranesi
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Julian Paganini
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Adriana S Limansky
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jorgelina Moran-Barrio
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Suzana P Salcedo
- Laboratory of Molecular Microbiology and Structural Biochemistry, CNRS UMR5086, University of Lyon, LyonF-69367, France
| | - Alejandro M Viale
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Guillermo D Repizo
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.,Laboratory of Molecular Microbiology and Structural Biochemistry, CNRS UMR5086, University of Lyon, LyonF-69367, France
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6
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Statistical analysis of variability in TnSeq data across conditions using zero-inflated negative binomial regression. BMC Bioinformatics 2019; 20:603. [PMID: 31752678 PMCID: PMC6873424 DOI: 10.1186/s12859-019-3156-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/14/2019] [Indexed: 12/12/2022] Open
Abstract
Background Deep sequencing of transposon mutant libraries (or TnSeq) is a powerful method for probing essentiality of genomic loci under different environmental conditions. Various analytical methods have been described for identifying conditionally essential genes whose tolerance for insertions varies between two conditions. However, for large-scale experiments involving many conditions, a method is needed for identifying genes that exhibit significant variability in insertions across multiple conditions. Results In this paper, we introduce a novel statistical method for identifying genes with significant variability of insertion counts across multiple conditions based on Zero-Inflated Negative Binomial (ZINB) regression. Using likelihood ratio tests, we show that the ZINB distribution fits TnSeq data better than either ANOVA or a Negative Binomial (in a generalized linear model). We use ZINB regression to identify genes required for infection of M. tuberculosis H37Rv in C57BL/6 mice. We also use ZINB to perform a analysis of genes conditionally essential in H37Rv cultures exposed to multiple antibiotics. Conclusions Our results show that, not only does ZINB generally identify most of the genes found by pairwise resampling (and vastly out-performs ANOVA), but it also identifies additional genes where variability is detectable only when the magnitudes of insertion counts are treated separately from local differences in saturation, as in the ZINB model.
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7
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Cerqueira NMFSA, Fernandes PA, Ramos MJ. Protocol for Computational Enzymatic Reactivity Based on Geometry Optimisation. Chemphyschem 2018; 19:669-689. [DOI: 10.1002/cphc.201700339] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 09/22/2017] [Indexed: 01/12/2023]
Affiliation(s)
- N. M. F. S. A. Cerqueira
- REQUIMTE-UCIBIO; Departamento de Química e Bioquímica; Faculdade de Ciências; Universidade do Porto; Rua do Campo Alegre s/n 4169-007 Porto Portugal
| | - P. A. Fernandes
- REQUIMTE-UCIBIO; Departamento de Química e Bioquímica; Faculdade de Ciências; Universidade do Porto; Rua do Campo Alegre s/n 4169-007 Porto Portugal
| | - M. J. Ramos
- REQUIMTE-UCIBIO; Departamento de Química e Bioquímica; Faculdade de Ciências; Universidade do Porto; Rua do Campo Alegre s/n 4169-007 Porto Portugal
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8
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Grimm I, Dumke J, Dreier J, Knabbe C, Vollmer T. Biofilm formation and transcriptome analysis of Streptococcus gallolyticus subsp. gallolyticus in response to lysozyme. PLoS One 2018; 13:e0191705. [PMID: 29373594 PMCID: PMC5786311 DOI: 10.1371/journal.pone.0191705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/10/2018] [Indexed: 02/06/2023] Open
Abstract
Streptococcus gallolyticus subsp. gallolyticus is a commensal bacterium of the human gastrointestinal tract, and a pathogen causing infective endocarditis and other biofilm-associated infections via exposed collagen. This study focuses on the characterization of the biofilm formation and collagen adhesion of S. gallolyticus subsp. gallolyticus under different conditions. In this study, it has been observed that the isolate UCN 34 is resistant to 20 mg/ml lysozyme in BHI medium, whereas the strain BAA-2069 builds more biofilm in the presence of lysozyme compared to in a control of BHI without lysozyme. A transcriptome analysis with whole genome microarrays of these two isolates in BHI medium with lysozyme compared to control without lysozyme revealed changes in gene expression levels. In the isolate BAA-2069, 67 genes showed increased expression in the presence of lysozyme, while in the isolate UCN 34, 165 genes showed increased expression and 30 genes showed decreased expression through lysozyme treatment. Products of genes which were higher expressed are in involved in transcription and translation, in cell-wall modification, in hydrogen peroxide resistance and in bacterial immunity. Furthermore, the adhesion ability of different strains of S. gallolyticus subsp. gallolyticus to collagen type I and IV was analyzed. Thereby, we compared the adhesion of 46 human isolates with 23 isolates from animals. It was shown that the adhesion ability depends significantly on whether the isolate was isolated from human or animal. For example, high adhesion ability was observed for strain UCN 34 isolated from an infective endocarditis patient, whereas strain DSM 16831 isolated from koala feces adhered only marginally to collagen. Full genome microarray analysis of these two strains revealed strain-dependent gene expression due to adhesion. The expression of 25 genes of a transposon and 15 genes of a phage region in strain DSM 16831 were increased, which corresponds to horizontal gene transfer. Adherence to collagen in strain UCN 34 led to higher expression of 27 genes and lower expression of 31 genes. This was suggestive of a change in nutrient uptake.
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Affiliation(s)
- Imke Grimm
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Jessika Dumke
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Jens Dreier
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Cornelius Knabbe
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Tanja Vollmer
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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Martínez-Moñino AB, Zapata-Pérez R, García-Saura AG, Gil-Ortiz F, Pérez-Gilabert M, Sánchez-Ferrer Á. Characterization and mutational analysis of a nicotinamide mononucleotide deamidase from Agrobacterium tumefaciens showing high thermal stability and catalytic efficiency. PLoS One 2017; 12:e0174759. [PMID: 28388636 PMCID: PMC5384747 DOI: 10.1371/journal.pone.0174759] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/15/2017] [Indexed: 01/07/2023] Open
Abstract
NAD+ has emerged as a crucial element in both bioenergetic and signaling pathways since it acts as a key regulator of cellular and organismal homeostasis. Among the enzymes involved in its recycling, nicotinamide mononucleotide (NMN) deamidase is one of the key players in the bacterial pyridine nucleotide cycle, where it catalyzes the conversion of NMN into nicotinic acid mononucleotide (NaMN), which is later converted to NAD+ in the Preiss-Handler pathway. The biochemical characteristics of bacterial NMN deamidases have been poorly studied, although they have been investigated in some firmicutes, gamma-proteobacteria and actinobacteria. In this study, we present the first characterization of an NMN deamidase from an alphaproteobacterium, Agrobacterium tumefaciens (AtCinA). The enzyme was active over a broad pH range, with an optimum at pH 7.5. Moreover, the enzyme was quite stable at neutral pH, maintaining 55% of its activity after 14 days. Surprisingly, AtCinA showed the highest optimal (80°C) and melting (85°C) temperatures described for an NMN deamidase. The above described characteristics, together with its high catalytic efficiency, make AtCinA a promising biocatalyst for the production of pure NaMN. In addition, six mutants (C32A, S48A, Y58F, Y58A, T105A and R145A) were designed to study their involvement in substrate binding, and two (S31A and K63A) to determine their contribution to the catalysis. However, only four mutants (C32A, S48A Y58F and T105A) showed activity, although with reduced catalytic efficiency. These results, combined with a thermal and structural analysis, reinforce the Ser/Lys catalytic dyad mechanism as the most plausible among those proposed.
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Affiliation(s)
- Ana Belén Martínez-Moñino
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum”, University of Murcia, Campus Espinardo, E-30100 MURCIA, Spain
- Murcia Biomedical Research Institute (IMIB), Murcia, Spain
| | - Rubén Zapata-Pérez
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum”, University of Murcia, Campus Espinardo, E-30100 MURCIA, Spain
- Murcia Biomedical Research Institute (IMIB), Murcia, Spain
| | - Antonio Ginés García-Saura
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum”, University of Murcia, Campus Espinardo, E-30100 MURCIA, Spain
- Murcia Biomedical Research Institute (IMIB), Murcia, Spain
| | | | - Manuela Pérez-Gilabert
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum”, University of Murcia, Campus Espinardo, E-30100 MURCIA, Spain
- Murcia Biomedical Research Institute (IMIB), Murcia, Spain
| | - Álvaro Sánchez-Ferrer
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence “Campus Mare Nostrum”, University of Murcia, Campus Espinardo, E-30100 MURCIA, Spain
- Murcia Biomedical Research Institute (IMIB), Murcia, Spain
- * E-mail:
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Stehr M, Elamin AA, Singh M. Pyrazinamide: the importance of uncovering the mechanisms of action in mycobacteria. Expert Rev Anti Infect Ther 2015; 13:593-603. [PMID: 25746054 DOI: 10.1586/14787210.2015.1021784] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pyrazinamide (PZA) is still one of the key drugs used in current therapeutic regimens for tuberculosis (TB). Despite its importance for TB therapy, the mode of action of PZA remains unknown. PZA has to be converted to its active form pyrazinoic acid (POA) by the nicotinamidase PncA and is then excreted by an unknown efflux pump. At acidic conditions, POA is protonated to HPOA and is reabsorbed into the cell where it causes cellular damage. For a long time, it has been thought that PZA/POA has no defined target of action, but recent studies have shown that both PZA and POA have several different targets interfering with diverse biochemical pathways, especially in the NAD(+) and energy metabolism. PZA resistance seems to depend not only on a defective pyrazinamidase but is also rather a result of the interplay of many different enzyme targets and transport mechanisms.
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Affiliation(s)
- Matthias Stehr
- LIONEX Diagnostics and Therapeutics GmbH, Salzdahlumer Straße 196, D-38126, Braunschweig, Germany
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