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Jensen D, Ruiz Manzano A, Rector M, Tomko E, Record M, Galburt E. High-throughput, fluorescent-aptamer-based measurements of steady-state transcription rates for the Mycobacterium tuberculosis RNA polymerase. Nucleic Acids Res 2023; 51:e99. [PMID: 37739412 PMCID: PMC10602862 DOI: 10.1093/nar/gkad761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/04/2023] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
The first step in gene expression is the transcription of DNA sequences into RNA. Regulation at the level of transcription leads to changes in steady-state concentrations of RNA transcripts, affecting the flux of downstream functions and ultimately cellular phenotypes. Changes in transcript levels are routinely followed in cellular contexts via genome-wide sequencing techniques. However, in vitro mechanistic studies of transcription have lagged with respect to throughput. Here, we describe the use of a real-time, fluorescent-aptamer-based method to quantitate steady-state transcription rates of the Mycobacterium tuberculosis RNA polymerase. We present clear controls to show that the assay specifically reports on promoter-dependent, full-length RNA transcription rates that are in good agreement with the kinetics determined by gel-resolved, α-32P NTP incorporation experiments. We illustrate how the time-dependent changes in fluorescence can be used to measure regulatory effects of nucleotide concentrations and identity, RNAP and DNA concentrations, transcription factors, and antibiotics. Our data showcase the ability to easily perform hundreds of parallel steady-state measurements across varying conditions with high precision and reproducibility to facilitate the study of the molecular mechanisms of bacterial transcription.
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Affiliation(s)
- Drake Jensen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - Ana Ruiz Manzano
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - Maxwell Rector
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Eric J Tomko
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
| | - M Thomas Record
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Eric A Galburt
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63108, USA
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Jensen D, Manzano AR, Rector M, Tomko EJ, Record MT, Galburt EA. High-throughput, fluorescent-aptamer-based measurements of steady-state transcription rates for Mycobacterium tuberculosis RNA polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532464. [PMID: 36993414 PMCID: PMC10054983 DOI: 10.1101/2023.03.13.532464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The first step in gene expression is the transcription of DNA sequences into RNA. Regulation at the level of transcription leads to changes in steady-state concentrations of RNA transcripts, affecting the flux of downstream functions and ultimately cellular phenotypes. Changes in transcript levels are routinely followed in cellular contexts via genome-wide sequencing techniques. However, in vitro mechanistic studies of transcription have lagged with respect to throughput. Here, we describe the use of a real-time, fluorescent-aptamer-based method to quantitate steady-state transcription rates of the Mycobacterium tuberculosis RNA polymerase. We present clear controls to show that the assay specifically reports on promoter-dependent, full-length RNA transcription rates that are in good agreement with the kinetics determined by gel-resolved, α- 32 P NTP incorporation experiments. We illustrate how the time-dependent changes in fluorescence can be used to measure regulatory effects of nucleotide concentrations and identity, RNAP and DNA concentrations, transcription factors, and antibiotics. Our data showcase the ability to easily perform hundreds of parallel steady-state measurements across varying conditions with high precision and reproducibility to facilitate the study of the molecular mechanisms of bacterial transcription. Significance Statement RNA polymerase transcription mechanisms have largely been determined from in vitro kinetic and structural biology methods. In contrast to the limited throughput of these approaches, in vivo RNA sequencing provides genome-wide measurements but lacks the ability to dissect direct biochemical from indirect genetic mechanisms. Here, we present a method that bridges this gap, permitting high-throughput fluorescence-based measurements of in vitro steady-state transcription kinetics. We illustrate how an RNA-aptamer-based detection system can be used to generate quantitative information on direct mechanisms of transcriptional regulation and discuss the far-reaching implications for future applications.
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Affiliation(s)
- Drake Jensen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - Ana Ruiz Manzano
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - Maxwell Rector
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Eric J. Tomko
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
| | - M. Thomas Record
- Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Eric A. Galburt
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, 63108, USA
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Staudinger T, Redl B, Glasgow BJ. Antibacterial activity of rifamycins for M. smegmatis with comparison of oxidation and binding to tear lipocalin. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1844:750-8. [PMID: 24530503 PMCID: PMC3992280 DOI: 10.1016/j.bbapap.2014.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 01/28/2014] [Accepted: 02/03/2014] [Indexed: 11/19/2022]
Abstract
A mutant of Mycobacterium smegmatis is a potential class I model substitute for Mycobacterium tuberculosis. Because not all of the rifamycins have been tested in this organism, we determined bactericidal profiles for the 6 major rifamycin derivatives. The profiles closely mirrored those established for M. tuberculosis. Rifalazil was confirmed to be the most potent rifamycin. Because the tuberculous granuloma presents a harshly oxidizing environment we explored the effects of oxidation on rifamycins. Mass spectrometry confirmed that three of the six major rifamycins showed autoxidation in the presence of trace metals. Oxidation could be monitored by distinctive changes including isosbestic points in the ultraviolet-visible spectrum. Oxidation of rifamycins abrogated anti-mycobacterial activity in M. smegmatis. Protection from autoxidation was conferred by binding susceptible rifamycins to tear lipocalin, a promiscuous lipophilic protein. Rifalazil was not susceptible to autoxidation but was insoluble in aqueous solution. Solubility was enhanced when complexed to tear lipocalin and was accompanied by a spectral red shift. The positive solvatochromism was consistent with robust molecular interaction and binding. Other rifamycins also formed a complex with lipocalin, albeit to a lesser extent. Protection from oxidation and enhancement of solubility with protein binding may have implications for delivery of select rifamycin derivatives.
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Affiliation(s)
- Tamara Staudinger
- Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Bernhard Redl
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Ben J Glasgow
- Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Rm. B-279, Los Angeles, CA 90095, USA.
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Mondol T, Batabyal S, Pal SK. Interaction of an antituberculosis drug with nano-sized cationic micelle: Förster resonance energy transfer from dansyl to rifampicin in the microenvironment. Photochem Photobiol 2012; 88:328-35. [PMID: 22211727 DOI: 10.1111/j.1751-1097.2012.01075.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this contribution, we report studies on the interaction of an antituberculosis drug rifampicin (RF) in a macromolecular assembly of CTAB with an extrinsic fluorescent probe, dansyl chloride (DC). The absorption spectrum of the drug RF has been employed to study Förster resonance energy transfer (FRET) from DC, bound to the CTAB micelle using picosecond resolved fluorescence spectroscopy. We have applied a kinetic model developed by Tachiya to understand the kinetics of energy transfer and the distribution of acceptor (RF) molecules around the donor (DC) molecules in the micellar surface with increasing quencher concentration. The mean number of RF molecules associated with the micelle increases from 0.24 at 20 μm RF concentration to 1.5 at 190 μm RF concentration and consequently the quenching rate constant (k(q)) due to the acceptor (RF) molecules increases from 0.23 to 0.75 ns(-1) at 20 and 190 μm RF concentration, respectively. However, the mean number of the quencher molecule and the quenching rate constant does not change significantly beyond a certain RF concentration (150 μm), which is consistent with the results obtained from time resolved FRET analysis. Moreover, we have explored the diffusion controlled FRET between DC and RF, using microfluidics setup, which reveals that the reaction pathway follows one-step process.
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Affiliation(s)
- Tanumoy Mondol
- Department of Chemical, Biological & Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata, India
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Rajdev P, Mondol T, Makhal A, Pal SK. Simultaneous binding of anti-tuberculosis and anti-thrombosis drugs to a human transporter protein: A FRET study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 103:153-8. [DOI: 10.1016/j.jphotobiol.2011.02.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 02/25/2011] [Accepted: 02/28/2011] [Indexed: 11/29/2022]
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Mondol T, Rajdev P, Makhal A, Pal SK. Interaction of an Antituberculosis Drug with a Nanoscopic Macromolecular Assembly: Temperature-Dependent Förster Resonance Energy Transfer Studies on Rifampicin in an Anionic Sodium Dodecyl Sulfate Micelle. J Phys Chem B 2011; 115:2924-30. [DOI: 10.1021/jp108115h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tanumoy Mondol
- Unit for Nano Science & Technology, Department of Chemical, Biological, and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Priya Rajdev
- Unit for Nano Science & Technology, Department of Chemical, Biological, and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Abhinandan Makhal
- Unit for Nano Science & Technology, Department of Chemical, Biological, and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Samir Kumar Pal
- Unit for Nano Science & Technology, Department of Chemical, Biological, and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Welsh FW, Murray WD, Williams RE, Katz I. Microbiological and Enzymatic Production of Flavor and Fragrance Chemicals. Crit Rev Biotechnol 2008. [DOI: 10.3109/07388558909040617] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Antibiotic association with phospholipid nano-assemblies: A comparison between Langmuir–Blodgett films and supported lipid bilayers. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2008.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lowder JF, Johnson RS. The generation of the rifamycin binding site in the beta subunit of E. coli RNA polymerase through subunit interactions. Biochem Biophys Res Commun 1987; 147:1129-36. [PMID: 3311043 DOI: 10.1016/s0006-291x(87)80187-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Spectral studies were performed using rifampicin quinone to investigate the generation of the rifamycin binding site in the beta subunit of E. coli RNA polymerase due to subunit interactions. The spectrum of rifampicin quinone is not significantly altered in the presence of the beta subunit. In the case of the alpha 2 beta subassembly, a negative difference spectral band at 330 nm is observed for rifampicin quinone, whereas in the presence of either the holoenzyme or core polymerase a positive band at 348 and a negative one at 318 are observed. In affinity labeling studies using 3-(2-bromo[1-14C]acetamidoethyl)-thiorifamycin, it was demonstrated that the isolated beta subunit is nonspecifically modified by this reagent. However, in the case of both the alpha 2 beta subassembly and core polymerase, the beta subunit is specifically modified.
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Affiliation(s)
- J F Lowder
- Department of Biochemistry, East Carolina University, School of Medicine, Greenville, NC 27858
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Conditional rifampicin sensitivity of arif mutant ofEscherichia coli: rifampicin induced changes in transcription specificity. J Biosci 1985. [DOI: 10.1007/bf02702697] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Johnson RS. A resonance Raman study on the interaction of rifampicin with Escherichia coli RNA polymerase. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 839:16-25. [PMID: 3884050 DOI: 10.1016/0304-4165(85)90176-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The technique of resonance Raman spectroscopy has been used to investigate the interaction of the antibiotic rifampicin with Escherichia coli RNA polymerase. Spectra were analyzed by generating the first derivative of each recorded spectrum using the Savitsky-Golay algorithm. The only band that shifted significantly in the resonance Raman spectrum of rifampicin upon the formation of the drug-core polymerase complex was the amide III band. It underwent an 8 cm-1 shift from 1306 cm-1 in aqueous solution to 1314 cm-1. A comparable shift was observed for the rifampicin-holoenzyme complex. Thus, the interaction of the sigma subunit with the core polymerase does not significantly alter the manner in which rifampicin interacts with RNA polymerase. The nature of this shift has been analyzed further by recording the resonance Raman spectrum of rifampicin in a variety of solvents with different hydrogen-bonding solvents (benzene and carbon disulfide) the amide III band was observed at approximately 1220 cm-1; in dimethyl sulfoxide, a weak hydrogen-bond acceptor, 1274 cm-1; in water, a strong hydrogen-bonding solvent, 1306 cm-1; and finally, in triethylamine, a stronger hydrogen-bonding solvent than water, it was observed at 1314 cm-1. Thus, as the hydrogen-bonding ability of the solvent increased, the amide III band shifted to higher frequency. Based on these results, the rifampicin binding site in RNA polymerase provides a stronger hydrogen-bonding environment for the amidic proton of rifampicin than is encountered when rifampicin is free in aqueous solution.
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