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Selezneva AI, Harding LNM, Gutka HJ, Movahedzadeh F, Abad-Zapatero C. New structures of Class II Fructose-1,6-Bisphosphatase from Francisella tularensis provide a framework for a novel catalytic mechanism for the entire class. PLoS One 2023; 18:e0274723. [PMID: 37352301 PMCID: PMC10289334 DOI: 10.1371/journal.pone.0274723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 06/06/2023] [Indexed: 06/25/2023] Open
Abstract
Class II Fructose-1,6-bisphosphatases (FBPaseII) (EC: 3.1.3.11) are highly conserved essential enzymes in the gluconeogenic pathway of microorganisms. Previous crystallographic studies of FBPasesII provided insights into various inactivated states of the enzyme in different species. Presented here is the first crystal structure of FBPaseII in an active state, solved for the enzyme from Francisella tularensis (FtFBPaseII), containing native metal cofactor Mn2+ and complexed with catalytic product fructose-6-phosphate (F6P). Another crystal structure of the same enzyme complex is presented in the inactivated state due to the structural changes introduced by crystal packing. Analysis of the interatomic distances among the substrate, product, and divalent metal cations in the catalytic centers of the enzyme led to a revision of the catalytic mechanism suggested previously for class II FBPases. We propose that phosphate-1 is cleaved from the substrate fructose-1,6-bisphosphate (F1,6BP) by T89 in a proximal α-helix backbone (G88-T89-T90-I91-T92-S93-K94) in which the substrate transition state is stabilized by the positive dipole of the 〈-helix backbone. Once cleaved a water molecule found in the active site liberates the inorganic phosphate from T89 completing the catalytic mechanism. Additionally, a crystal structure of Mycobacterium tuberculosis FBPaseII (MtFBPaseII) containing a bound F1,6BP is presented to further support the substrate binding and novel catalytic mechanism suggested for this class of enzymes.
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Affiliation(s)
- Anna I. Selezneva
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Luke N. M. Harding
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Hiten J. Gutka
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Celerino Abad-Zapatero
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
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Selezneva AI, Gutka HJ, Wolf NM, Qurratulain F, Movahedzadeh F, Abad-Zapatero C. Structural and biochemical characterization of the class II fructose-1,6-bisphosphatase from Francisella tularensis. Acta Crystallogr F Struct Biol Commun 2020; 76:524-535. [PMID: 33135671 PMCID: PMC7605111 DOI: 10.1107/s2053230x20013370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/05/2020] [Indexed: 11/10/2022] Open
Abstract
The crystal structure of the class II fructose-1,6-bisphosphatase (FBPaseII) from the important pathogen Francisella tularensis is presented at 2.4 Å resolution. Its structural and functional relationships to the closely related phosphatases from Mycobacterium tuberculosis (MtFBPaseII) and Escherichia coli (EcFBPaseII) and to the dual phosphatase from Synechocystis strain 6803 are discussed. FBPaseII from F. tularensis (FtFBPaseII) was crystallized in a monoclinic crystal form (space group P21, unit-cell parameters a = 76.30, b = 100.17, c = 92.02 Å, β = 90.003°) with four chains in the asymmetric unit. Chain A had two coordinated Mg2+ ions in its active center, which is distinct from previous findings, and is presumably deactivated by their presence. The structure revealed an approximate 222 (D2) symmetry homotetramer analogous to that previously described for MtFBPaseII, which is formed by a crystallographic dyad and which differs from the exact tetramer found in EcFBPaseII at a 222 symmetry site in the crystal. Instead, the approximate homotetramer is very similar to that found in the dual phosphatase from Synechocystis, even though no allosteric effector was found in FtFBPase. The amino-acid sequence and folding of the active site of FtFBPaseII result in structural characteristics that are more similar to those of the previously published EcFBPaseII than to those of MtFBPaseII. The kinetic parameters of native FtFBPaseII were found to be in agreement with published studies. Kinetic analyses of the Thr89Ser and Thr89Ala mutations in the active site of the enzyme are consistent with the previously proposed mechanism for other class II bisphosphatases. The Thr89Ala variant enzyme was inactive but the Thr89Ser variant was partially active, with an approximately fourfold lower Km and Vmax than the native enzyme. The structural and functional insights derived from the structure of FtFBPaseII will provide valuable information for the design of specific inhibitors.
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Affiliation(s)
- Anna I. Selezneva
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Hiten J. Gutka
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Nina M. Wolf
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Fnu Qurratulain
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Celerino Abad-Zapatero
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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Bondoc JMG, Gutka HJ, Almutairi MM, Patwell R, Rutter MW, Wolf NM, Samudrala R, Mehboob S, Dementiev A, Abad-Zapatero C, Movahedzadeh F. Rv0100, a proposed acyl carrier protein in Mycobacterium tuberculosis: expression, purification and crystallization. Corrigendum. Acta Crystallogr F Struct Biol Commun 2020; 76:192-193. [PMID: 32254053 PMCID: PMC7137385 DOI: 10.1107/s2053230x2000271x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 11/10/2022] Open
Abstract
The true identity of the protein found in the crystals reported by Bondoc et al. [(2019), Acta Cryst. F75, 646-651] is given.
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Affiliation(s)
- Jasper Marc G Bondoc
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Hiten J Gutka
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Mashal M Almutairi
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Ryan Patwell
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Maxwell W Rutter
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Nina M Wolf
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Ram Samudrala
- Department of Biomedical Informatics, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY), University at Buffalo, 77 Goodell Street, Buffalo, NY 14203, USA
| | - Shahila Mehboob
- NovaScan Inc., 950 N. 12th Street, Milwaukee,, WI 53233, USA
| | - Alexey Dementiev
- Structural Biology Center, Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Cele Abad-Zapatero
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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Bondoc JMG, Gutka HJ, Almutairi MM, Patwell R, Rutter MW, Wolf NM, Samudrala R, Mehboob S, Movahedzadeh F. Rv0100, a proposed acyl carrier protein in Mycobacterium tuberculosis: expression, purification and crystallization. Acta Crystallogr F Struct Biol Commun 2019; 75:646-651. [PMID: 31584013 PMCID: PMC6777135 DOI: 10.1107/s2053230x19012652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/11/2019] [Indexed: 11/10/2022] Open
Abstract
Acyl carrier proteins (ACPs) are important components in fatty-acid biosynthesis in prokaryotes. Rv0100 is predicted to be an essential ACP in Mycobacterium tuberculosis, the pathogen that is the causative agent of tuberculosis, and therefore has the potential to be a novel antituberculosis drug target. Here, the successful cloning and purification of Rv0100 using Mycobacterium smegmatis as a host is reported. Crystals of the purified protein were obtained that diffracted to a resolution of 1.9 Å. Overall, this work lays the foundation for the future pursuit of drug discovery and development against this potentially novel drug target.
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Affiliation(s)
- Jasper Marc G. Bondoc
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Hiten J. Gutka
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
- Oncobiologics Inc., 7 Clarke Drive, Cranbury, NJ 08512, USA
| | - Mashal M. Almutairi
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 12371, Saudi Arabia
- Vaccines and Biologics Research Unit, College of Pharmacy, King Saud University, Riyadh 12371, Saudi Arabia
- Department of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Ryan Patwell
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
- Department of Psychiatry, University of Illinois at Chicago, 1601 West Taylor Street, Room 425, Chicago, IL 60612, USA
| | - Maxwell W. Rutter
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
- Hollingbery and Son Hops Inc., 302 North First Avenue, Yakima, WA 98907, USA
| | - Nina M. Wolf
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | - Ram Samudrala
- Department of Biomedical Informatics, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY), University at Buffalo, 77 Goodell Street, Buffalo, NY 14203, USA
| | - Shahila Mehboob
- Neugenica LLC, 2242 West Harrison Street #201, Chicago, IL 60612, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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Wolf NM, Gutka HJ, Movahedzadeh F, Abad-Zapatero C. Structures of the Mycobacterium tuberculosis GlpX protein (class II fructose-1,6-bisphosphatase): implications for the active oligomeric state, catalytic mechanism and citrate inhibition. Acta Crystallogr D Struct Biol 2018; 74:321-331. [PMID: 29652259 PMCID: PMC5892879 DOI: 10.1107/s2059798318002838] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/16/2018] [Indexed: 11/19/2022] Open
Abstract
The crystal structures of native class II fructose-1,6-bisphosphatase (FBPaseII) from Mycobacterium tuberculosis at 2.6 Å resolution and two active-site protein variants are presented. The variants were complexed with the reaction product fructose 6-phosphate (F6P). The Thr84Ala mutant is inactive, while the Thr84Ser mutant has a lower catalytic activity. The structures reveal the presence of a 222 tetramer, similar to those described for fructose-1,6/sedoheptulose-1,7-bisphosphatase from Synechocystis (strain 6803) as well as the equivalent enzyme from Thermosynechococcus elongatus. This homotetramer corresponds to a homologous oligomer that is present but not described in the crystal structure of FBPaseII from Escherichia coli and is probably conserved in all FBPaseIIs. The constellation of amino-acid residues in the active site of FBPaseII from M. tuberculosis (MtFBPaseII) is conserved and is analogous to that described previously for the E. coli enzyme. Moreover, the structure of the active site of the partially active (Thr84Ser) variant and the analysis of the kinetics are consistent with the previously proposed catalytic mechanism. The presence of metabolites in the crystallization medium (for example citrate and malonate) and in the corresponding crystal structures of MtFBPaseII, combined with their observed inhibitory effect, could suggest the existence of an uncharacterized inhibition of this class of enzymes besides the allosteric inhibition by adenosine monophosphate observed for the Synechocystis enzyme. The structural and functional insights derived from the structure of MtFBPaseII will provide critical information for the design of lead inhibitors, which will be used to validate this target for future chemical intervention.
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Affiliation(s)
- Nina M. Wolf
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Hiten J. Gutka
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois, USA
- Oncobiologics Inc., Cranbury, New Jersey, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Celerino Abad-Zapatero
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, Illinois, USA
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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Gutka HJ, Wolf NM, Bondoc JMG, Movahedzadeh F. Enzymatic Characterization of Fructose 1,6-Bisphosphatase II from Francisella tularensis, an Essential Enzyme for Pathogenesis. Appl Biochem Biotechnol 2017; 183:1439-1454. [PMID: 28547120 PMCID: PMC5698383 DOI: 10.1007/s12010-017-2512-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/11/2017] [Indexed: 11/27/2022]
Abstract
The glpX gene from Francisella tularensis encodes for the class II fructose 1,6-bisphosphatase (FBPaseII) enzyme. The glpX gene has been verified to be essential in F. tularensis, and the inactivation of this gene leads to impaired bacterial growth on gluconeogenic substrates. In the present work, we have complemented a ∆glpX mutant of Escherichia coli with the glpX gene of F. tularensis (FTF1631c). Our complementation work independently verifies that the glpX gene (FTF1631c) in F. tularensis is indeed an FBPase and supports the growth of the ΔglpX E. coli mutant on glycerol-containing media. We have performed heterologous expression and purification of the glpX encoded FBPaseII in F. tularensis. We have confirmed the function of glpX as an FBPase and optimized the conditions for enzymatic activity. Mn2+ was found to be an absolute requirement for activity, with no other metal substitutions rendering the enzyme active. The kinetic parameters for this enzyme were found as follows: Km 11 μM, Vmax 2.0 units/mg, kcat 1.2 s-1, kcat/Km 120 mM-1 s-1, and a specific activity of 2.0 units/mg. Size exclusion data suggested an abundance of a tetrameric species in solution. Our findings on the enzyme's properties will facilitate the initial stages of a structure-based drug design program targeting this essential gene of F. tularensis.
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Affiliation(s)
- Hiten J Gutka
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
- Oncobiologics Inc., Cranbury, NJ, USA
| | - Nina M Wolf
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Jasper Marc G Bondoc
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
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Gutka HJ, Wang Y, Franzblau SG, Movahedzadeh F. glpx Gene in Mycobacterium tuberculosis Is Required for In Vitro Gluconeogenic Growth and In Vivo Survival. PLoS One 2015; 10:e0138436. [PMID: 26397812 PMCID: PMC4580611 DOI: 10.1371/journal.pone.0138436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/31/2015] [Indexed: 11/18/2022] Open
Abstract
Several enzymes involved in central carbon metabolism and gluconeogenesis play a critical role in survival and pathogenesis of Mycobacterium tuberculosis (Mtb). The only known functional fructose 1,6-bisphosphatase (FBPase) in Mtb is encoded by the glpX gene and belongs to the Class II sub-family of FBPase. We describe herein the generation of a ΔglpX strain using homologous recombination. Although the growth profile of ΔglpX is comparable to that of wild type Mtb when grown on the standard enrichment media, its growth is dysgonic with individual gluconeogenic substrates such as oleic acid, glycerol and acetate. In mice lung CFU titers of ΔglpX were 2-3 log10 lower than the wild-type Mtb strain. The results indicate that glpX gene encodes a functional FBPase and is essential for both in vitro and in vivo growth and survival of Mtb. Loss of glpX results in significant reduction of FBPase activity but not complete abolition. These findings verify that the glpX encoded FBPase II in Mtb can be a potential target for drug discovery.
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Affiliation(s)
- Hiten J. Gutka
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yuehong Wang
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Gutka HJ, Franzblau SG, Movahedzadeh F, Abad-Zapatero C. Crystallization and preliminary X-ray characterization of the glpX-encoded class II fructose-1,6-bisphosphatase from Mycobacterium tuberculosis. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:710-3. [PMID: 21636919 PMCID: PMC3107150 DOI: 10.1107/s1744309111014722] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 04/19/2011] [Indexed: 11/11/2022]
Abstract
Fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11), which is a key enzyme in gluconeogenesis, catalyzes the hydrolysis of fructose 1,6-bisphosphate to form fructose 6-phosphate and orthophosphate. The present investigation reports the crystallization and preliminary crystallographic studies of the glpX-encoded class II FBPase from Mycobacterium tuberculosis H37Rv. The recombinant protein, which was cloned using an Escherichia coli expression system, was purified and crystallized using the hanging-drop vapor-diffusion method. The crystals diffracted to a resolution of 2.7 Å and belonged to the hexagonal space group P6(1)22, with unit-cell parameters a = b = 131.3, c = 143.2 Å. The structure has been solved by molecular replacement and is currently undergoing refinement.
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Affiliation(s)
- Hiten J. Gutka
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Cele Abad-Zapatero
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, Chicago, IL 60607, USA
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Abstract
The sequence of Mycobacterium tuberculosis, completed in 1998, facilitated both the development of genomic tools, and the creation of a number of mycobacterial mutants. These mutants have a wide range of phenotypes, from attenuated to hypervirulent strains. These phenotypes must be confirmed, to rule out possible secondary mutations that may arise during the generation of mutant strains. This may occur during the amplification of target genes or during the generation of the mutation, thus constructing a complementation strain, which expresses the wild-type copy of the gene in the mutant strain, becomes necessary. In this study we have introduced a two-step strategy to construct complementation strains using the Ag85 promoter. We have constitutively expressed dosR and have shown dosR expression is restored to wild-type level.
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Affiliation(s)
- Farahnaz Movahedzadeh
- Department of Pathology and Infectious Diseases, Royal Veterinary College, London, UK
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Gutka HJ, Rukseree K, Wheeler PR, Franzblau SG, Movahedzadeh F. glpX gene of Mycobacterium tuberculosis: heterologous expression, purification, and enzymatic characterization of the encoded fructose 1,6-bisphosphatase II. Appl Biochem Biotechnol 2011; 164:1376-89. [PMID: 21451980 DOI: 10.1007/s12010-011-9219-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 03/01/2011] [Indexed: 12/22/2022]
Abstract
The glpX gene (Rv1099c) of Mycobacterium tuberculosis (Mtb) encodes Fructose 1,6-bisphosphatase II (FBPase II; EC 3.1.3.11); a key gluconeogenic enzyme. Mtb possesses glpX homologue as the major known FBPase. This study explored the expression, purification and enzymatic characterization of functionally active FBPase II from Mtb. The glpX gene was cloned, expressed and purified using a two step purification strategy including affinity and size exclusion chromatography. The specific activity of Mtb FBPase II is 1.3 U/mg. The enzyme is oligomeric, followed Michaelis-Menten kinetics with an apparent km = 44 μM. Enzyme activity is dependent on bivalent metal ions and is inhibited by lithium and inorganic phosphate. The pH optimum and thermostability of the enzyme have been determined. The robust expression, purification and assay protocols ensure sufficient production of this protein for structural biology and screening of inhibitors against this enzyme.
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Affiliation(s)
- Hiten J Gutka
- Institute for Tuberculosis Research (M/C 964), College of Pharmacy, Room 412, University of Illinois at Chicago, 833 S. Wood St, Chicago, IL 60612-7231, USA
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