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Liu L, Zhao N, Yang K, Liao H, Liu X, Wu Y, Wang Y, Peng X, Wu Y. Proteomic Analysis of Staphylococcus aureus Treated with ShangKeHuangShui. Biol Pharm Bull 2024; 47:292-302. [PMID: 38281773 DOI: 10.1248/bpb.b23-00471] [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] [Indexed: 01/30/2024]
Abstract
Staphylococcus aureus (SAU) stands as the prevailing pathogen in post-traumatic infections, with the emergence of antibiotic resistance presenting formidable treatment hurdles. The pressing need is to explore novel antibiotics to address this challenge. ShangKeHuangShui (SKHS), a patented traditional Chinese herbal formula, has gained widespread use in averting post-traumatic infections, but its biological effects remain incomplete understanding. This study's primary objective was to delve into the antibacterial properties, potential antibacterial compounds within SKHS, and their associated molecular targets. In vitro SKHS antibacterial assays demonstrated that the minimum inhibitory concentration (MIC) was 8.625 mg/mL and the minimum bactericide concentration (MBC) was 17.25 mg/mL. Proteomic analysis based on tandem mass tag (TMT) showed significant changes in the expression level of 246 proteins in SKHS treated group compared to control group, with 79 proteins upregulated and 167 proteins downregulated (>1.5-fold, p < 0.05). Subsequently, thirteen target proteins related to various biological processes and multiple metabolic pathways were selected to conduct parallel reaction monitoring (PRM) and molecular docking screen. In protein tyrosine phosphatase PtpA (ptpA) docking screening, phellodendrine and obacunone can bind to ptpA with the binding energy of - 8.4 and - 8.3 kcal/mol, respectively. This suggests their potential impact on antibacterial activity by modulating the two-component system of SAU. The discovery lays a groundwork for future research endeavors for exploring new antibacterial candidates and elucidating specific active chemical components within SKHS that match target proteins. Further investigations are imperative to unveil the biological effects of these monomers and their potential synergistic actions.
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Affiliation(s)
- Lichu Liu
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Na Zhao
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Kuangyang Yang
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Honghong Liao
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Xiaofang Liu
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Ying Wu
- Laboratory Medicine Center, Foshan Hospital of Traditional Chinese Medicine
| | - Yan Wang
- Center for Translational Medicine Research and Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences
| | - Xiao Peng
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
| | - Yuanyan Wu
- Institute of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine
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Wei Y, Dong B, Wu X, Zhao M, Wang D, Li N, Zhang Q, Zhang L, Zhou H. RpoZ regulates 2,4-DAPG production and quorum sensing system in Pseudomonas fluorescens 2P24. Front Microbiol 2023; 14:1160913. [PMID: 37250031 PMCID: PMC10213339 DOI: 10.3389/fmicb.2023.1160913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/26/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction Pseudomonas fluorescens 2P24 was isolated from soil of natural decay associated with wheat take-all and it can effectively control soil-borne diseases caused by a variety of plant pathogens. 2,4-diacetylphloroglucinol (2,4-DAPG), is produced by P. fluorescens 2P24 and plays an important role in the prevention and control of plant diseases. To understand the resistant mechanism, in this study, we conducted experiments to explore the regulation role of rpoZ in the synthesis of the antibiotic 2,4-DAPG and regulation of QS system. Methods A random mini-Tn5 mutagenesis procedure was used to screen regulators for phlA transcription in stain PM901, which containing a phlA∷lacZ transcriptional fusion reporter plasmid. We identified 12 insertion mutants could significantly change phlA gene expression. By analyzing the amino acid sequences of the interrupted gene, we obtained a mutant strain Aa4-29 destroyed the rpoZ gene, which encodes the omiga subunit. We constructed the plasmid of rpoZ mutant (pBBR-△rpoZ) transformed into competent cells of P. fluorescens 2P24 by electro-transformation assay. The strains of P. fluorescens 2P24/pBBR, 2P24-△rpoZ/pBBR, 2P24-△rpoZ/pBBR-rpoZ were used to evaluate the regulation role of rpoZ in 2,4-DAPG production and quorum sensing system. Results According to β-galactosidase activity, we found that rpoZ positively regulated the expression of phlA (a synthesis gene of 2,4-DAPG) and PcoI (a synthesis gene of PcoI/PcoR QS signal system) at the transcriptional level. The production of 2,4-DAPG antibiotic and signal molecule AHL was influenced by rpoZ. Further, rpoZ was involved in regulating rsmA expression. RpoZ also has a certain regulatory effect on rpoS transcription, but no effect on the transcription of phlF, emhABC and emhR. According to the biocontrol assay, P. fluorescens 2P24 strains with rpoZ showed obvious antagonism ability against the Rhizoctonia solani in cotton, while the mutant strain of rpoZ lost the biocontrol effect. RpoZ had a significant effect on the swimming and biofilm formation in P. fluorescens 2P24. Conclusion Our data showed that rpoZ was an important regulator of QS system, 2,4-DAPG in P. fluorescens 2P24. This may imply that P. fluorescens 2P24 has evolved different regulatory features to adapt to different environmental threats.
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Affiliation(s)
- Yarui Wei
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China
| | - Baozhu Dong
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China
| | - Xiaogang Wu
- College of Agriculture, Guangxi University, Nanning, China
| | - Mingmin Zhao
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China
| | - Dong Wang
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China
| | - Na Li
- Erdos Agricultural and Animal Husbandry Technology Promotion Center, Erdos, Inner Mongolia, China
| | - Qian Zhang
- Bayannaoer Agriculture and Animal Husbandry Technology Promotion Center, Bayannaoer, Inner Mongolia, China
| | - Liqun Zhang
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Hongyou Zhou
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China
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Lv Z, Yin S, Jiang K, Wang W, Luan Y, Wu S, Shi J, Li Z, Ma X, Wang Z, Yan H. The whole-cell proteome shows the characteristics of macrolides-resistant Bordetella pertussis in China linked to the biofilm formation. Arch Microbiol 2023; 205:219. [PMID: 37148370 PMCID: PMC10164027 DOI: 10.1007/s00203-023-03566-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 05/08/2023]
Abstract
The macrolides-resistant Bordetella pertussis (MR-Bp) isolates in China evolved from the ptxP1/fhaB3 allele and rapidly became predominant, suggestive of an adaptive transmission ability. This was different from the global prevalent ptxP3 strains, in which MR-Bp was rarely reported. The study aimed to determine the underlying mechanism responsible for fitness and resistance in these two strains. We identify proteomic differences between ptxP1/fhaB3 and ptxP3/fhaB1 strains using tandem mass tag (TMT)-based proteomics. We then performed in-depth bioinformatic analysis to determine differentially expressed genes (DEGs), followed by gene ontology (GO), and protein-protein interaction (PPI) network analysis. Further parallel reaction monitoring (PRM) analysis confirmed the expression of four target proteins. Finally, the crystal violet method was used to determine biofilm-forming ability. The results showed that the main significantly different proteins between the two represent isolates were related to biofilm formation. Furthermore, we have confirmed that ptxP1/fhaB3 showed hyperbiofilm formation in comparison with ptxP3/fhaB1. It is suggested that the resistance and adaptability of ptxP1/fhaB3 strains may be related to the formation of biofilm through proteomics. In a word, we determined the significantly different proteins between the ptxP1/fhaB3 and ptxP3/fhaB1 strains through whole-cell proteome, which were related to biofilm formation.
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Affiliation(s)
- Zhe Lv
- Department of Epidemiology and Health Statistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China
| | - Sha Yin
- National Regional Children's Medical Center (Northwest), Key Laboratory of Precision Medicine to Pediatric Diseases of Shaanxi Province, Xi'an Key Laboratory of Children's Health and Diseases, Shaanxi Institute for Pediatric Diseases; Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China
| | - Kaichong Jiang
- National Regional Children's Medical Center (Northwest), Key Laboratory of Precision Medicine to Pediatric Diseases of Shaanxi Province, Xi'an Key Laboratory of Children's Health and Diseases, Shaanxi Institute for Pediatric Diseases; Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China
| | - Wei Wang
- Department of Clinical Laboratory, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China
| | - Yang Luan
- Xi'an Center for Disease Control and Prevention, 599 Xiying Road, Xi'an, 710054, China
| | - Shuang Wu
- Department of Clinical Laboratory, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China
| | - Jianfei Shi
- Department of Clinical Laboratory, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China
| | - Zhe Li
- Department of Diphtheria, Tetanus and Pertussis Vaccine and Toxins, National Institute for Food and Drug Control, Beijing, China
| | - Xiao Ma
- Department of Diphtheria, Tetanus and Pertussis Vaccine and Toxins, National Institute for Food and Drug Control, Beijing, China
| | - Zengguo Wang
- Department of Clinical Laboratory, Xi'an Children's Hospital, Affiliated Children's Hospital of Xi'an Jiaotong University, No. 69, Xijuyuan Lane, Xi'an, 710003, China.
| | - Hong Yan
- Department of Epidemiology and Health Statistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China.
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Long DR, Penewit K, Lo HY, Almazan J, Holmes EA, Bryan AB, Wolter DJ, Lewis JD, Waalkes A, Salipante SJ. In Vitro Selection Identifies Staphylococcus aureus Genes Influencing Biofilm Formation. Infect Immun 2023; 91:e0053822. [PMID: 36847490 PMCID: PMC10016075 DOI: 10.1128/iai.00538-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023] Open
Abstract
Staphylococcus aureus generates biofilms during many chronic human infections, which contributes to its growth and persistence in the host. Multiple genes and pathways necessary for S. aureus biofilm production have been identified, but knowledge is incomplete, and little is known about spontaneous mutations that increase biofilm formation as infection progresses. Here, we performed in vitro selection of four S. aureus laboratory strains (ATCC 29213, JE2, N315, and Newman) to identify mutations associated with enhanced biofilm production. Biofilm formation increased in passaged isolates from all strains, exhibiting from 1.2- to 5-fold the capacity of parental lines. Whole-genome sequencing identified nonsynonymous mutations affecting 23 candidate genes and a genomic duplication encompassing sigB. Six candidate genes significantly impacted biofilm formation as isogenic transposon knockouts: three were previously reported to impact S. aureus biofilm formation (icaR, spdC, and codY), while the remaining three (manA, narH, and fruB) were newly implicated by this study. Plasmid-mediated genetic complementation of manA, narH, and fruB transposon mutants corrected biofilm deficiencies, with high-level expression of manA and fruB further enhancing biofilm formation over basal levels. This work recognizes genes not previously identified as contributing to biofilm formation in S. aureus and reveals genetic changes able to augment biofilm production by that organism.
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Affiliation(s)
- Dustin R. Long
- Division of Critical Care Medicine, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Kelsi Penewit
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Hsin-Yu Lo
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Jared Almazan
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Elizabeth A. Holmes
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Andrew B. Bryan
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Daniel J. Wolter
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
| | - Janessa D. Lewis
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Adam Waalkes
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Stephen J. Salipante
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, Washington, USA
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Cheng A, Wan D, Ghatak A, Wang C, Feng D, Fondell JD, Ebright RH, Fan H. Identification and Structural Modeling of the RNA Polymerase Omega Subunits in Chlamydiae and Other Obligate Intracellular Bacteria. mBio 2023; 14:e0349922. [PMID: 36719197 PMCID: PMC9973325 DOI: 10.1128/mbio.03499-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 01/04/2023] [Indexed: 02/01/2023] Open
Abstract
Gene transcription in bacteria is carried out by the multisubunit RNA polymerase (RNAP), which is composed of a catalytic core enzyme and a promoter-recognizing σ factor. The core enzyme comprises two α subunits, one β subunit, one β' subunit, and one ω subunit. The ω subunit plays critical roles in the assembly of the core enzyme and other cellular functions, including the regulation of bacterial growth, the stress response, and biofilm formation. However, the identity of an ω subunit for the obligate intracellular bacterium Chlamydia has not previously been determined. Here, we report the identification of the hypothetical protein CTL0286 as the probable chlamydial ω subunit based on sequence, synteny, and AlphaFold and AlphaFold-Multimer three-dimensional-structure predictions. Our findings indicate that CTL0286 functions as the missing ω subunit of chlamydial RNAP. Our extended analysis also indicates that all obligate intracellular bacteria have ω orthologs. IMPORTANCE Chlamydiae are obligate intracellular bacteria that replicate only inside eukaryotic cells. Previously, it has not been possible to identify a candidate gene encoding the chlamydial RNA polymerase ω subunit, and it has been hypothesized that the chlamydial RNA polymerase ω subunit was lost in the evolutionary process through which Chlamydiae reduced their genome size and proteome sizes to adapt to an obligate intracellular lifestyle. Here, we report the identification of the chlamydial RNA polymerase ω subunit, based on conserved sequence, conserved synteny, AlphaFold-predicted conserved three-dimensional structure, and AlfaFold-Multimer-predicted conserved interactions. Our identification of the previously elusive chlamydial RNA polymerase ω subunit sets the stage for investigation of its roles in regulation of gene expression during chlamydial growth, development, and stress responses, and sets the stage for preparation and study of the intact chlamydial RNA polymerase and its interactions with inhibitors.
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Affiliation(s)
- Andrew Cheng
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Danny Wan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
- Graduate Program in Physiology and Integrative Biology, Rutgers School of Graduate Studies, Piscataway, New Jersey, USA
| | - Arkaprabha Ghatak
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Chengyuan Wang
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Deyu Feng
- Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Joseph D. Fondell
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Richard H. Ebright
- Waksman Institute, Rutgers University, Piscataway, New Jersey, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Huizhou Fan
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
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Banerjee A, Mukherjee D, Bera A, Ghosh R, Mondal S, Mukhopadhyay S, Das R, Altass HM, Natto SSA, Moussa Z, Ahmed SA, Chattopadhyay A, Pal SK. Molecular co-localization of multiple drugs in a nanoscopic delivery vehicle for potential synergistic remediation of multi-drug resistant bacteria. Sci Rep 2022; 12:18881. [PMID: 36344591 PMCID: PMC9640573 DOI: 10.1038/s41598-022-22759-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/19/2022] [Indexed: 11/09/2022] Open
Abstract
Anti-microbial resistant infection is predicted to be alarming in upcoming years. In the present study, we proposed co-localization of two model drugs viz., rifampicin and benzothiazole used in anti-tuberculosis and anti-fungal agents respectively in a nanoscopic cationic micelle (cetyl triethyl ammonium bromide) with hydrodynamic diameter of 2.69 nm. Sterilization effect of the co-localized micellar formulation against a model multi-drug resistant bacterial strain viz., Methicillin resistant Staphylococcus aureus was also investigated. 99.88% decrease of bacterial growth in terms of colony forming unit was observed using the developed formulation. While Dynamic Light Scattering and Forsters Resonance Energy Transfer between benzothiazole and rifampicin show co-localization of the drugs in the nanoscopic micellar environment, analysis of time-resolved fluorescence decays by Infelta-Tachiya model and the probability distribution of the donor-acceptor distance fluctuations for 5 μM,10 μM and 15 μM acceptor concentrations confirm efficacy of the co-localization. Energy transfer efficiency and the donor acceptor distance are found to be 46% and 20.9 Å respectively. We have also used a detailed computational biology framework to rationalize the sterilization effect of our indigenous formulation. It has to be noted that the drugs used in our studies are not being used for their conventional indication. Rather the co-localization of the drugs in the micellar environment shows a completely different indication of their use in the remediation of multi-drug resistant bacteria revealing the re-purposing of the drugs for potential use in hospital-born multi-drug resistant bacterial infection.
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Affiliation(s)
- Amrita Banerjee
- Department of Physics, Jadavpur University, 188, Raja S.C. Mallick Rd, Kolkata, 700032, India
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, 700106, West Bengal, India
| | - Dipanjan Mukherjee
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Arpan Bera
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Ria Ghosh
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Susmita Mondal
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India
| | - Subhadipta Mukhopadhyay
- Department of Physics, Jadavpur University, 188, Raja S.C. Mallick Rd, Kolkata, 700032, India
| | - Ranjan Das
- Department of Chemistry, West Bengal State University, Kolkata, 700106, India
| | - Hatem M Altass
- Chemistry Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Sameer S A Natto
- Physcis Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Ziad Moussa
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, P.O. Box 15551, Abu Dhabi, United Arab Emirates
| | - Saleh A Ahmed
- Chemistry Department, Faculty of Applied Science, Umm Al-Qura University, Mecca, 21955, Saudi Arabia.
| | - Arpita Chattopadhyay
- Department of Basic Science and Humanities, Techno International New Town Block, DG 1/1, Action Area 1 New Town, Rajarhat, Kolkata, 700156, India.
- Department of Physics, Sister Nivedita University, DG 1/2 New Town, Action Area 1, Kolkata, 700156, India.
| | - Samir Kumar Pal
- Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Kolkata, 700106, India.
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Sherlock D, Fogg PCM. The archetypal gene transfer agent RcGTA is regulated via direct interaction with the enigmatic RNA polymerase omega subunit. Cell Rep 2022; 40:111183. [PMID: 35947951 PMCID: PMC9638019 DOI: 10.1016/j.celrep.2022.111183] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/06/2022] [Accepted: 07/19/2022] [Indexed: 12/03/2022] Open
Abstract
Gene transfer agents (GTAs) are small virus-like particles that indiscriminately package and transfer any DNA present in their host cell, with clear implications for bacterial evolution. The first transcriptional regulator that directly controls GTA expression, GafA, was recently discovered, but its mechanism of action has remained elusive. Here, we demonstrate that GafA controls GTA gene expression via direct interaction with the RNA polymerase omega subunit (Rpo-ω) and also positively autoregulates its own expression by an Rpo-ω-independent mechanism. We show that GafA is a modular protein with distinct DNA and protein binding domains. The functional domains we observe in Rhodobacter GafA also correspond to two-gene operons in Hyphomicrobiales pathogens. These data allow us to produce the most complete regulatory model for a GTA and point toward an atypical mechanism for RNA polymerase recruitment and specific transcriptional activation in the Alphaproteobacteria.
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Affiliation(s)
- David Sherlock
- Biology Department, University of York, York YO10 5DD, UK
| | - Paul C M Fogg
- Biology Department, University of York, York YO10 5DD, UK; York Biomedical Research Institute (YBRI), University of York, York YO10 5NG, UK.
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Transcriptomic Analysis Reveals that Changes in Gene Expression Contribute to Microbacterium sediminis YLB-01 Adaptation at Low Temperature Under High Hydrostatic Pressure. Curr Microbiol 2022; 79:95. [PMID: 35150317 DOI: 10.1007/s00284-022-02786-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 01/25/2022] [Indexed: 11/03/2022]
Abstract
Microbes living in extreme environments often adopt strategies for survival, however, only a few studies have examined the adaptive mechanism of deep-sea bacteria in in-situ environments. In this study, transcriptomic data of the deep-sea piezotolerant and psychrotolerant actinomycete Microbacterium sediminis YLB-01 under the conditions of NPNT (normal temperature and pressure: 28 °C, 0.1 MPa), HPNT (normal temperature and high pressure: 28 °C, 30 MPa), NPLT (low temperature and atmospheric pressure: 4 °C, 0.1 MPa) and HPLT (low temperature and high pressure: 4 °C, 30 MPa) were examined and compared. Transcriptome results showed that M. sediminis YLB-01 responds to deep-sea low temperature under high-pressure environments by upregulating the ABC transport system, DNA damage repair response, pentose phosphate pathway, amino acid metabolism and fatty acid metabolism, while down-regulating division, oxidative phosphorylation, the TCA cycle, pyruvate metabolism, ion transport and peptidoglycan biosynthesis. Seven key genes specifically expressed under HPLT conditions were screened, and these genes are present in many strains that are tolerant to low temperatures and high pressures. This study provides transcription level insights into the tolerance mechanisms of M. sediminis YLB-01 in a simulated deep-sea in situ environment.
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9
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Ethanol as additive enhances expression of Ranibizumab in Escherichia coli: Impact on cellular physiology and transcriptome. Process Biochem 2022. [DOI: 10.1016/j.procbio.2021.11.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Carvalho IGB, Merfa MV, Teixeira-Silva NS, Martins PMM, Takita MA, de Souza AA. Overexpression of mqsR in Xylella fastidiosa Leads to a Priming Effect of Cells to Copper Stress Tolerance. Front Microbiol 2021; 12:712564. [PMID: 34616378 PMCID: PMC8488296 DOI: 10.3389/fmicb.2021.712564] [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: 05/20/2021] [Accepted: 08/09/2021] [Indexed: 12/13/2022] Open
Abstract
Copper-based compounds are widely used in agriculture as a chemical strategy to limit the spread of multiple plant diseases; however, the continuous use of this heavy metal has caused environmental damage as well as the development of copper-resistant strains. Thus, it is important to understand how the bacterial phytopathogens evolve to manage with this metal in the field. The MqsRA Toxin-Antitoxin system has been recently described for its function in biofilm formation and copper tolerance in Xylella fastidiosa, a plant-pathogen bacterium responsible for economic damage in several crops worldwide. Here we identified differentially regulated genes by X. fastidiosa MqsRA by assessing changes in global gene expression with and without copper. Results show that mqsR overexpression led to changes in the pattern of cell aggregation, culminating in a global phenotypic heterogeneity, indicative of persister cell formation. This phenotype was also observed in wild-type cells but only in the presence of copper. This suggests that MqsR regulates genes that alter cell behavior in order to prime them to respond to copper stress, which is supported by RNA-Seq analysis. To increase cellular tolerance, proteolysis and efflux pumps and regulator related to multidrug resistance are induced in the presence of copper, in an MqsR-independent response. In this study we show a network of genes modulated by MqsR that is associated with induction of persistence in X. fastidiosa. Persistence in plant-pathogenic bacteria is an important genetic tolerance mechanism still neglected for management of phytopathogens in agriculture, for which this work expands the current knowledge and opens new perspectives for studies aiming for a more efficient control in the field.
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Affiliation(s)
| | - Marcus Vinicius Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | | | | | - Marco Aurélio Takita
- Centro de Citricultura Sylvio Moreira, Instituto Agronômico, Cordeirópolis, Brazil
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11
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Kurkela J, Fredman J, Salminen TA, Tyystjärvi T. Revealing secrets of the enigmatic omega subunit of bacterial RNA polymerase. Mol Microbiol 2021; 115:1-11. [PMID: 32920946 DOI: 10.1111/mmi.14603] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/14/2022]
Abstract
The conserved omega (ω) subunit of RNA polymerase (RNAP) is the only nonessential subunit of bacterial RNAP core. The small ω subunit (7 kDa-11.5 kDa) contains three conserved α helices, and helices α2 and α3 contain five fully conserved amino acids of ω. Four conserved amino acids stabilize the correct folding of the ω subunit and one is located in the vicinity of the β' subunit of RNAP. Otherwise ω shows high variation between bacterial taxa, and although the main interaction partner of ω is always β', many interactions are taxon-specific. ω-less strains show pleiotropic phenotypes, and based on in vivo and in vitro results, a few roles for the ω subunits have been described. Interactions of the ω subunit with the β' subunit are important for the RNAP core assembly and integrity. In addition, the ω subunit plays a role in promoter selection, as ω-less RNAP cores recruit fewer primary σ factors and more alternative σ factors than intact RNAP cores in many species. Furthermore, the promoter selection of an ω-less RNAP holoenzyme bearing the primary σ factor seems to differ from that of an intact RNAP holoenzyme.
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Affiliation(s)
- Juha Kurkela
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Julia Fredman
- Faculty of Science and Engineering/Biochemistry/Structural Bioinformatics Laboratory, Åbo Akademi University, Turku, Finland
| | - Tiina A Salminen
- Faculty of Science and Engineering/Biochemistry/Structural Bioinformatics Laboratory, Åbo Akademi University, Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
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12
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Ho H, Fang JR, Cheung J, Wang HH. Programmable CRISPR-Cas transcriptional activation in bacteria. Mol Syst Biol 2020; 16:e9427. [PMID: 32657546 PMCID: PMC7356669 DOI: 10.15252/msb.20199427] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 06/07/2020] [Accepted: 06/16/2020] [Indexed: 11/30/2022] Open
Abstract
Programmable gene activation enables fine-tuned regulation of endogenous and synthetic gene circuits to control cellular behavior. While CRISPR-Cas-mediated gene activation has been extensively developed for eukaryotic systems, similar strategies have been difficult to implement in bacteria. Here, we present a generalizable platform for screening and selection of functional bacterial CRISPR-Cas transcription activators. Using this platform, we identified a novel CRISPR activator, dCas9-AsiA, that could activate gene expression by more than 200-fold across genomic and plasmid targets with diverse promoters after directed evolution. The evolved dCas9-AsiA can simultaneously mediate activation and repression of bacterial regulons in E. coli. We further identified hundreds of promoters with varying basal expression that could be induced by dCas9-AsiA, which provides a rich resource of genetic parts for inducible gene activation. Finally, we show that dCas9-AsiA can be ported to other bacteria of clinical and bioindustrial relevance, thus enabling bacterial CRISPRa in more application areas. This work expands the toolbox for programmable gene regulation in bacteria and provides a useful resource for future engineering of other bacterial CRISPR-based gene regulators.
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Affiliation(s)
- Hsing‐I Ho
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
| | - Jennifer R Fang
- Department of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Jacky Cheung
- Department of Computer Science and BiologyColumbia UniversityNew YorkNYUSA
| | - Harris H Wang
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Department of Pathology and Cell BiologyColumbia UniversityNew YorkNYUSA
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13
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Fang JY, Lin YK, Wang PW, Alalaiwe A, Yang YC, Yang SC. The Droplet-Size Effect Of Squalene@cetylpyridinium Chloride Nanoemulsions On Antimicrobial Potency Against Planktonic And Biofilm MRSA. Int J Nanomedicine 2019; 14:8133-8147. [PMID: 31632023 PMCID: PMC6790405 DOI: 10.2147/ijn.s221663] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/16/2019] [Indexed: 01/01/2023] Open
Abstract
Background It is important to explore the interaction between antibacterial nanoparticles and microbes for understanding bactericidal activity and developing novel applications. It is possible that the nanoparticulate size can govern the antibacterial potency. Purpose The purpose of this study was to evaluate the antimicrobial and antibiofilm properties of cetylpyridinium chloride (CPC)–decorated nanoemulsions against methicillin-resistant Staphylococcus aureus (MRSA). Methods The droplet size could be adjusted by varying the percentage of squalene, the main ingredient of the oily core. Results We fabricated cationic nanoemulsions of three different sizes, 55, 165, and 245 nm. The nanoemulsions showed greater storage stability than the self-assembled CPC micelles. The tested nanoemulsions exhibited more antimicrobial activity against Gram-positive bacteria than Gram-negative bacteria and fungi. The killing of MRSA was mainly induced by direct cell-membrane damage. This rupture led to the leakage of cytoplasmic DNA and proteins. The nanoemulsions might also degrade the DNA helix and disturb protein synthesis. The proteomic analysis indicated the significant downregulation of DNA-directed RNA polymerase (RNAP) subunits β and β’. The antibacterial effect of nanoemulsions increased with decreasing droplet size in the biofilm MRSA but not planktonic MRSA. The small-sized nanoemulsions had potent antibiofilm activity that showed a colony-forming unit (CFU) reduction of 10-fold compared with the control. The loss of total DNA concentration also negatively correlated with the nanoemulsion size. Conclusion The present report established a foundation for the development of squalene@CPC nanosystems against drug-resistant S. aureus.
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Affiliation(s)
- Jia-You Fang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan.,Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Kweishan, Taoyuan, Taiwan.,Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Kweishan, Taoyuan, Taiwan.,Department of Anesthesiology, Chang Gung Memorial Hospital, Kweishan, Taoyuan, Taiwan
| | - Yin-Ku Lin
- School of Traditional Chinese Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan.,Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan
| | - Pei-Wen Wang
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Ahmed Alalaiwe
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia
| | - Yu-Ching Yang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - Shih-Chun Yang
- Department of Cosmetic Science, Providence University, Taichung, Taiwan
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14
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Yang SC, Tang KW, Lin CH, Alalaiwe A, Tseng CH, Fang JY. Discovery of Furanoquinone Derivatives as a Novel Class of DNA Polymerase and Gyrase Inhibitors for MRSA Eradication in Cutaneous Infection. Front Microbiol 2019; 10:1197. [PMID: 31191504 PMCID: PMC6549599 DOI: 10.3389/fmicb.2019.01197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/13/2019] [Indexed: 11/26/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is the primary microbe responsible for skin infections that are particularly difficult to eradicate. This study sought to inhibit planktonic and biofilm MRSA using furanoquinone-derived compounds containing imine moiety. A total of 19 furanoquinone analogs were designed, synthesized, and assessed for anti-MRSA potency. Among 19 compounds, (Z)-4-(hydroxyimino)naphtho[1,2-b]furan-5(4H)-one (HNF) and (Z)-4-(acetoxyimino)naphtho[1,2-b]furan-5(4H)-one (ANF) showed antibacterial activity superior to the others based on an agar diffusion assay. HNF and ANF exerted a bactericidal effect with a minimum inhibitory concentration (MIC) of 9.7 ∼ 19.5 and 2.4 ∼ 9.7 μg/ml, respectively. Both compounds were able to reduce the MRSA count by 1,000-fold in biofilm as compared to the control. In vivo efficacy was evaluated using a mouse model of skin infection. Topical application of lead compounds significantly suppressed abscess occurrence and the MRSA burden, and also ameliorated the skin-barrier function. The biochemical assay indicated the compounds’ inhibition of DNA polymerase and gyrase. In silico docking revealed a favorable interaction of the compounds with DNA polymerase and gyrase although the binding was not very strong. The total DNA analysis and proteomic data suggested a greater impairment of some proteins by HNF than ANF. In general, HNF and ANF were similarly potent in MRSA inhibition in vitro and in vivo. The findings demonstrated that there was room for structural modification of furanoquinone compounds that could be used to identify anti-MRSA agent candidates.
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Affiliation(s)
- Shih-Chun Yang
- Department of Cosmetic Science, Providence University, Taichung, Taiwan
| | - Kai-Wei Tang
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Hung Lin
- Center for General Education, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Ahmed Alalaiwe
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia
| | - Chih-Hua Tseng
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Department of Pharmacy, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan
| | - Jia-You Fang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan.,Chinese Herbal Medicine Research Team, Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan.,Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Taoyuan, Taiwan.,Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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15
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MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. Infect Immun 2019; 87:IAI.00002-19. [PMID: 30833335 DOI: 10.1128/iai.00002-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/23/2019] [Indexed: 01/07/2023] Open
Abstract
Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant, we observed a drastic reduction in proteolysis, hemolysis, and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA sequencing data sets for both mroQ and agr mutants revealed a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr-controlling effect; however, this was not wielded at the level of AgrD processing. Virulence assessment demonstrated that both mroQ and agr mutants exhibited increased formation of renal abscesses but decreased skin abscess formation alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.
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16
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Ramaniuk O, Převorovský M, Pospíšil J, Vítovská D, Kofroňová O, Benada O, Schwarz M, Šanderová H, Hnilicová J, Krásný L. σ I from Bacillus subtilis: Impact on Gene Expression and Characterization of σ I-Dependent Transcription That Requires New Types of Promoters with Extended -35 and -10 Elements. J Bacteriol 2018; 200:e00251-18. [PMID: 29914988 PMCID: PMC6088155 DOI: 10.1128/jb.00251-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/09/2018] [Indexed: 11/20/2022] Open
Abstract
The σI sigma factor from Bacillus subtilis is a σ factor associated with RNA polymerase (RNAP) that was previously implicated in adaptation of the cell to elevated temperature. Here, we provide a comprehensive characterization of this transcriptional regulator. By transcriptome sequencing (RNA-seq) of wild-type (wt) and σI-null strains at 37°C and 52°C, we identified ∼130 genes affected by the absence of σI Further analysis revealed that the majority of these genes were affected indirectly by σI The σI regulon, i.e., the genes directly regulated by σI, consists of 16 genes, of which eight (the dhb and yku operons) are involved in iron metabolism. The involvement of σI in iron metabolism was confirmed phenotypically. Next, we set up an in vitro transcription system and defined and experimentally validated the promoter sequence logo that, in addition to -35 and -10 regions, also contains extended -35 and -10 motifs. Thus, σI-dependent promoters are relatively information rich in comparison with most other promoters. In summary, this study supplies information about the least-explored σ factor from the industrially important model organism B. subtilisIMPORTANCE In bacteria, σ factors are essential for transcription initiation. Knowledge about their regulons (i.e., genes transcribed from promoters dependent on these σ factors) is the key for understanding how bacteria cope with the changing environment and could be instrumental for biotechnologically motivated rewiring of gene expression. Here, we characterize the σI regulon from the industrially important model Gram-positive bacterium Bacillus subtilis We reveal that σI affects expression of ∼130 genes, of which 16 are directly regulated by σI, including genes encoding proteins involved in iron homeostasis. Detailed analysis of promoter elements then identifies unique sequences important for σI-dependent transcription. This study thus provides a comprehensive view on this underexplored component of the B. subtilis transcription machinery.
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Affiliation(s)
- Olga Ramaniuk
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Pospíšil
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dragana Vítovská
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Olga Kofroňová
- Laboratory of Molecular Structure Characterization, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Oldřich Benada
- Laboratory of Molecular Structure Characterization, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marek Schwarz
- Laboratory of Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Šanderová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jarmila Hnilicová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
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17
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Association of ω with the C-Terminal Region of the β' Subunit Is Essential for Assembly of RNA Polymerase in Mycobacterium tuberculosis. J Bacteriol 2018; 200:JB.00159-18. [PMID: 29632095 DOI: 10.1128/jb.00159-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/02/2018] [Indexed: 11/20/2022] Open
Abstract
The ω subunit is the smallest subunit of bacterial RNA polymerase (RNAP). Although homologs of ω are essential in both eukaryotes and archaea, this subunit has been known to be dispensable for RNAP in Escherichia coli and in other bacteria. In this study, we characterized an indispensable role of the ω subunit in Mycobacterium tuberculosis Unlike the well-studied E. coli RNAP, the M. tuberculosis RNAP core enzyme cannot be functionally assembled in the absence of the ω subunit. Importantly, substitution of M. tuberculosis ω with ω subunits from E. coli or Thermus thermophilus cannot restore the assembly of M. tuberculosis RNAP. Furthermore, by replacing different regions in M. tuberculosis ω with the corresponding regions from E. coli ω, we found a nonconserved loop region in M. tuberculosis ω essential for its function in RNAP assembly. From RNAP structures, we noticed that the location of the C-terminal region of the β' subunit (β'CTD) in M. tuberculosis RNAP but not in E. coli or T. thermophilus RNAP is close to the ω loop region. Deletion of this β'CTD in M. tuberculosis RNAP destabilized the binding of M. tuberculosis ω on RNAP and compromised M. tuberculosis core assembly, suggesting that these two regions may function together to play a role in ω-dependent RNAP assembly in M. tuberculosis Sequence alignment of the ω loop and the β'CTD regions suggests that the essential role of ω is probably restricted to mycobacteria. Together, our study characterized an essential role of M. tuberculosis ω and highlighted the importance of the ω loop region in M. tuberculosis RNAP assembly.IMPORTANCE DNA-dependent RNA polymerase (RNAP), which consists of a multisubunit core enzyme (α2ββ'ω) and a dissociable σ subunit, is the only enzyme in charge of transcription in bacteria. As the smallest subunit, the roles of ω remain the least well studied. In Escherichia coli and some other bacteria, the ω subunit is known to be nonessential for RNAP. In this study, we revealed an essential role of the ω subunit for RNAP assembly in the human pathogen Mycobacterium tuberculosis, and a mycobacterium-specific ω loop that plays a role in this function was also characterized. Our study provides fresh insights for further characterizing the roles of bacterial ω subunit.
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18
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Bhardwaj N, Syal K, Chatterji D. The role of ω-subunit of Escherichia coli RNA polymerase in stress response. Genes Cells 2018. [PMID: 29542212 DOI: 10.1111/gtc.12577] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ppGpp, an alarmone for stringent response, plays an important role in the reprogramming of the transcription complex at the time of stress. In Escherichia coli, ppGpp mediates its action by binding to at least two different sites on RNA polymerase (RNAP). One of the sites to which ppGpp binds to RNAP is at the β'-ω interface; however, the underlying molecular mechanism and the physiological relevance of ppGpp binding to this site remain unclear. In this study, we have performed UV cross-linking experiments using 32 P azido-labeled ppGpp to probe its association with RNAP in the absence and presence of ω, and observed weaker binding of ppGpp to the RNAP without ω. Furthermore, we followed the binding kinetics of ppGpp to RNAP with and without ω by isothermal titration calorimetry and found it to be concurrent with the cross-linking results. Native ω is intrinsically disordered, and we have used a previously characterized structured mutant of ω, which affects the plasticity of the active site of RNAP. Results show that the flexibility conferred by the unstructured ω is a prerequisite for ppGpp binding to RNAP. We have analyzed the stress-associated phenotypes in an E. coli strain devoid of ω (∆rpoZ). ppGpp levels in ∆rpoZ strain were found to be similar to that of the wild-type strain. Interestingly, when the ∆rpoZ strain of E. coli was transferred after nutritional stress to an enriched media, the recovery of growth was compromised. We have identified a new phenotype of ∆rpoZ strain corresponding to defect in biofilm formation in minimal media.
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Affiliation(s)
- Neerupma Bhardwaj
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Kirtimaan Syal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Dipankar Chatterji
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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Westbye AB, O'Neill Z, Schellenberg-Beaver T, Beatty JT. The Rhodobacter capsulatus gene transfer agent is induced by nutrient depletion and the RNAP omega subunit. Microbiology (Reading) 2017; 163:1355-1363. [DOI: 10.1099/mic.0.000519] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Alexander B. Westbye
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada
- Present address: Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 't Horntje (Texel), Netherlands
| | - Zoe O'Neill
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada
| | - Tegan Schellenberg-Beaver
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada
| | - J. Thomas Beatty
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada
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20
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Kurkela J, Hakkila K, Antal T, Tyystjärvi T. Acclimation to High CO 2 Requires the ω Subunit of the RNA Polymerase in Synechocystis. PLANT PHYSIOLOGY 2017; 174:172-184. [PMID: 28351910 PMCID: PMC5411146 DOI: 10.1104/pp.16.01953] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/23/2017] [Indexed: 06/06/2023]
Abstract
Inactivation of the nonessential ω-subunit of the RNA polymerase core in the ΔrpoZ strain of the model cyanobacterium Synechocystis sp. PCC 6803 leads to a unique high-CO2-sensitive phenotype. Supplementing air in the growth chamber with 30 mL L-1 (3%) CO2 accelerated the growth rate of the control strain (CS) 4-fold, whereas ΔrpoZ did not grow faster than under ambient air. The slow growth of ΔrpoZ during the first days in high CO2 was due to the inability of the mutant cells to adjust photosynthesis to high CO2 The light-saturated photosynthetic activity of ΔrpoZ in high CO2 was only half of that measured in CS, Rubisco content was one-third lower, and cells of ΔrpoZ were not able to increase light-harvesting phycobilisome antenna like CS upon high-CO2 treatment. In addition, altered structural and functional organization of photosystem I and photosystem II were detected in the ΔrpoZ strain compared with CS when cells were grown in high CO2 but not in ambient air. Moreover, respiration of ΔrpoZ did not acclimate to high CO2 Unlike the photosynthetic complexes, the RNA polymerase complex and ribosomes were produced in high CO2 similarly as in CS Our results indicate that the deletion of the ω-subunit specifically affects photosynthesis and respiration, but transcription and translation remain active. Thus, the specific effect of the ω-subunit on photosynthesis but not on all household processes suggests that the ω-subunit might have a regulatory function in cyanobacteria.
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Affiliation(s)
- Juha Kurkela
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Kaisa Hakkila
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Taras Antal
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Taina Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
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