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Zhang HS, Feng QD, Zhang DY, Zhu GL, Yang L. Bacterial community structure in geothermal springs on the northern edge of Qinghai-Tibet plateau. Front Microbiol 2023; 13:994179. [PMID: 37180363 PMCID: PMC10172933 DOI: 10.3389/fmicb.2022.994179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 12/13/2022] [Indexed: 03/19/2023] Open
Abstract
Introduction:In order to reveal the composition of the subsurface hydrothermal bacterial community in the zones of magmatic tectonics and their response to heat storage environments.Methods:In this study, we performed hydrochemical analysis and regional sequencing of the 16S rRNA microbial V4-V5 region in 7 Pleistocene and Lower Neogene hot water samples from the Gonghe basin.Results:Two geothermal hot spring reservoirs in the study area were found to be alkaline reducing environments with a mean temperature of 24.83°C and 69.28°C, respectively, and the major type of hydrochemistry was SO4-Cl·Na. The composition and structure of microorganisms in both types of geologic thermal storage were primarily controlled by temperature, reducing environment intensity, and hydrogeochemical processes. Only 195 ASVs were shared across different temperature environments, and the dominant bacterial genera in recent samples from temperate hot springs were Thermus and Hydrogenobacter, with both genera being typical of thermophiles. The correlation analysis showed that the overall level of relative abundance of the subsurface hot spring relied on a high temperature and a slightly alkaline reducing environment. Nearly all of the top 4 species in the abundance level (53.99% of total abundance) were positively correlated with temperature and pH, whereas they were negatively correlated with ORP (oxidation–reduction potential), nitrate, and bromine ions.Discussion:In general, the composition of bacteria in the groundwater in the study area was sensitive to the response of the thermal storage environment and also showed a relationship with geochemical processes, such as gypsum dissolution, mineral oxidation, etc.
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A Hyperthermoactive-Cas9 Editing Tool Reveals the Role of a Unique Arsenite Methyltransferase in the Arsenic Resistance System of Thermus thermophilus HB27. mBio 2021; 12:e0281321. [PMID: 34872358 PMCID: PMC8649762 DOI: 10.1128/mbio.02813-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Arsenic detoxification systems can be found in a wide range of organisms, from bacteria to humans. In a previous study, we discovered an arsenic-responsive transcriptional regulator in the thermophilic bacterium Thermus thermophilus HB27 (TtSmtB). Here, we characterize the arsenic resistance system of T. thermophilus in more detail. We employed TtSmtB-based pulldown assays with protein extracts from cultures treated with arsenate and arsenite to obtain an S-adenosyl-l-methionine (SAM)-dependent arsenite methyltransferase (TtArsM). In vivo and in vitro analyses were performed to shed light on this new component of the arsenic resistance network and its peculiar catalytic mechanism. Heterologous expression of TtarsM in Escherichia coli resulted in arsenite detoxification at mesophilic temperatures. Although TtArsM does not contain a canonical arsenite binding site, the purified protein does catalyze SAM-dependent arsenite methylation with formation of monomethylarsenites (MMAs) and dimethylarsenites (DMAs). In addition, in vitro analyses confirmed the unique interaction between TtArsM and TtSmtB. Next, a highly efficient ThermoCas9-based genome-editing tool was developed to delete the TtArsM-encoding gene on the T. thermophilus genome and to confirm its involvement in the arsenite detoxification system. Finally, the TtarsX efflux pump gene in the T. thermophilus ΔTtarsM genome was substituted by a gene encoding a stabilized yellow fluorescent protein (sYFP) to create a sensitive genome-based bioreporter system for the detection of arsenic ions.
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Sacristán-Horcajada E, González-de la Fuente S, Peiró-Pastor R, Carrasco-Ramiro F, Amils R, Requena JM, Berenguer J, Aguado B. ARAMIS: From systematic errors of NGS long reads to accurate assemblies. Brief Bioinform 2021; 22:bbab170. [PMID: 34013348 PMCID: PMC8574707 DOI: 10.1093/bib/bbab170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/31/2021] [Accepted: 04/11/2021] [Indexed: 01/23/2023] Open
Abstract
NGS long-reads sequencing technologies (or third generation) such as Pacific BioSciences (PacBio) have revolutionized the sequencing field over the last decade improving multiple genomic applications like de novo genome assemblies. However, their error rate, mostly involving insertions and deletions (indels), is currently an important concern that requires special attention to be solved. Multiple algorithms are available to fix these sequencing errors using short reads (such as Illumina), although they require long processing times and some errors may persist. Here, we present Accurate long-Reads Assembly correction Method for Indel errorS (ARAMIS), the first NGS long-reads indels correction pipeline that combines several correction software in just one step using accurate short reads. As a proof OF concept, six organisms were selected based on their different GC content, size and genome complexity, and their PacBio-assembled genomes were corrected thoroughly by this pipeline. We found that the presence of systematic sequencing errors in long-reads PacBio sequences affecting homopolymeric regions, and that the type of indel error introduced during PacBio sequencing are related to the GC content of the organism. The lack of knowledge of this fact leads to the existence of numerous published studies where such errors have been found and should be resolved since they may contain incorrect biological information. ARAMIS yields better results with less computational resources needed than other correction tools and gives the possibility of detecting the nature of the found indel errors found and its distribution along the genome. The source code of ARAMIS is available at https://github.com/genomics-ngsCBMSO/ARAMIS.git.
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Affiliation(s)
| | | | - R Peiró-Pastor
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
| | - F Carrasco-Ramiro
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
| | - R Amils
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
| | - J M Requena
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
| | - J Berenguer
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
| | - B Aguado
- Centro de Biología Molecular Severo Ochoa (CBMSO) (CSIC-UAM), Madrid, Spain
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Gallo G, Puopolo R, Carbonaro M, Maresca E, Fiorentino G. Extremophiles, a Nifty Tool to Face Environmental Pollution: From Exploitation of Metabolism to Genome Engineering. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:5228. [PMID: 34069056 PMCID: PMC8157027 DOI: 10.3390/ijerph18105228] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/06/2021] [Accepted: 05/09/2021] [Indexed: 12/13/2022]
Abstract
Extremophiles are microorganisms that populate habitats considered inhospitable from an anthropocentric point of view and are able to tolerate harsh conditions such as high temperatures, extreme pHs, high concentrations of salts, toxic organic substances, and/or heavy metals. These microorganisms have been broadly studied in the last 30 years and represent precious sources of biomolecules and bioprocesses for many biotechnological applications; in this context, scientific efforts have been focused on the employment of extremophilic microbes and their metabolic pathways to develop biomonitoring and bioremediation strategies to face environmental pollution, as well as to improve biorefineries for the conversion of biomasses into various chemical compounds. This review gives an overview on the peculiar metabolic features of certain extremophilic microorganisms, with a main focus on thermophiles, which make them attractive for biotechnological applications in the field of environmental remediation; moreover, it sheds light on updated genetic systems (also those based on the CRISPR-Cas tool), which expand the potentialities of these microorganisms to be genetically manipulated for various biotechnological purposes.
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Affiliation(s)
- Giovanni Gallo
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Napoli, Italy; (G.G.); (R.P.); (M.C.); (E.M.)
- Consiglio Nazionale delle Ricerche CNR, Institute of Polymers, Composites and Biomaterials (IPCB), Via Campi Flegrei, 34, 80078 Pozzuoli, Italy
| | - Rosanna Puopolo
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Napoli, Italy; (G.G.); (R.P.); (M.C.); (E.M.)
| | - Miriam Carbonaro
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Napoli, Italy; (G.G.); (R.P.); (M.C.); (E.M.)
| | - Emanuela Maresca
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Napoli, Italy; (G.G.); (R.P.); (M.C.); (E.M.)
| | - Gabriella Fiorentino
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Napoli, Italy; (G.G.); (R.P.); (M.C.); (E.M.)
- Consiglio Nazionale delle Ricerche CNR, Institute of Polymers, Composites and Biomaterials (IPCB), Via Campi Flegrei, 34, 80078 Pozzuoli, Italy
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Blesa A, Baquedano I, González-de la Fuente S, Mencía M, Berenguer J. Integrative and Conjugative Element ICETh1 Functions as a Pangenomic DNA Capture Module in Thermus thermophilus. Microorganisms 2020; 8:microorganisms8122051. [PMID: 33371442 PMCID: PMC7767461 DOI: 10.3390/microorganisms8122051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 11/16/2022] Open
Abstract
Transjugation is an unconventional conjugation mechanism in Thermus thermophilus (Tth) that involves the active participation of both mating partners, encompassing a DNA secretion system (DSS) in the donor and an active natural competence apparatus (NCA) in the recipient cells. DSS is encoded within an integrative and conjugative element (ICETh1) in the strain Tth HB27, whereas the NCA is constitutively expressed in both mates. Previous experiments suggested the presence of multiple origins of transfer along the genome, which could generate genomic mosaicity among the progeny. Here, we designed transjugation experiments between two closely related strains of Tth with highly syntenic genomes, containing enough single nucleotide polymorphisms to allow precise parenthood analysis. Individual clones from the progeny were sequenced, revealing their origin as derivatives of our ICETh1-containing intended “donor” strain (HB27), which had acquired separate fragments from the genome of the ICETh1-free HB8 cells, which are our intended recipient. Due to the bidirectional nature of transjugation, only assays employing competence-defective HB27 derivatives as donors allowed the recovery of HB8-derived progeny. These results show a preference for a retrotransfer mechanism in transjugation in ICETh1-bearing strains, supporting an inter-strain gene-capture function for ICETh1. This function could benefit the donor-capable host by facilitating the acquisition of adaptive traits from external sources, ultimately increasing the open pangenome of Thermus, maximizing the potential repertoire of physiological and phenotypical traits related to adaptation and speciation.
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Affiliation(s)
- Alba Blesa
- Department of Biotechnology, Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Madrid, Spain
- Correspondence: (A.B.); (J.B.); Tel.: +34-91194498 (J.B.)
| | - Ignacio Baquedano
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; (I.B.); (S.G.-d.l.F.); (M.M.)
| | - Sandra González-de la Fuente
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; (I.B.); (S.G.-d.l.F.); (M.M.)
| | - Mario Mencía
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; (I.B.); (S.G.-d.l.F.); (M.M.)
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain; (I.B.); (S.G.-d.l.F.); (M.M.)
- Correspondence: (A.B.); (J.B.); Tel.: +34-91194498 (J.B.)
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Artamonova D, Karneyeva K, Medvedeva S, Klimuk E, Kolesnik M, Yasinskaya A, Samolygo A, Severinov K. Spacer acquisition by Type III CRISPR-Cas system during bacteriophage infection of Thermus thermophilus. Nucleic Acids Res 2020; 48:9787-9803. [PMID: 32821943 PMCID: PMC7515739 DOI: 10.1093/nar/gkaa685] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/01/2020] [Accepted: 08/05/2020] [Indexed: 12/21/2022] Open
Abstract
Type III CRISPR–Cas systems provide immunity to foreign DNA by targeting its transcripts. Target recognition activates RNases and DNases that may either destroy foreign DNA directly or elicit collateral damage inducing death of infected cells. While some Type III systems encode a reverse transcriptase to acquire spacers from foreign transcripts, most contain conventional spacer acquisition machinery found in DNA-targeting systems. We studied Type III spacer acquisition in phage-infected Thermus thermophilus, a bacterium that lacks either a standalone reverse transcriptase or its fusion to spacer integrase Cas1. Cells with spacers targeting a subset of phage transcripts survived the infection, indicating that Type III immunity does not operate through altruistic suicide. In the absence of selection spacers were acquired from both strands of phage DNA, indicating that no mechanism ensuring acquisition of RNA-targeting spacers exists. Spacers that protect the host from the phage demonstrate a very strong strand bias due to positive selection during infection. Phages that escaped Type III interference accumulated deletions of integral number of codons in an essential gene and much longer deletions in a non-essential gene. This and the fact that Type III immunity can be provided by plasmid-borne mini-arrays open ways for genomic manipulation of Thermus phages.
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Affiliation(s)
- Daria Artamonova
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Karyna Karneyeva
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Sofia Medvedeva
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Evgeny Klimuk
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia.,Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia
| | - Matvey Kolesnik
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Anna Yasinskaya
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Aleksei Samolygo
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Konstantin Severinov
- Center of Life Science, Skolkovo Institute of Science and Technology, Moscow 121205, Russia.,Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia.,Waksman Institute, Rutgers, The State University of New Jersey, NJ 08854 USA
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Liu RR, Tian Y, Zhou EM, Xiong MJ, Xiao M, Li WJ. Distinct Expression of the Two NO-Forming Nitrite Reductases in Thermus antranikianii DSM 12462 T Improved Environmental Adaptability. MICROBIAL ECOLOGY 2020; 80:614-626. [PMID: 32474659 DOI: 10.1007/s00248-020-01528-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/14/2020] [Indexed: 05/21/2023]
Abstract
Hot spring ecosystems are analogous to some thermal environments on the early Earth and represent ideal models to understand life forms and element cycling on the early Earth. Denitrification, an important component of biogeochemical nitrogen cycle, is highly active in hot springs. Nitrite (NO2-) reduction to nitric oxide (NO) is the significant and rate-limiting pathway in denitrification and is catalyzed by two types of nitrite reductases, encoded by nirS and nirK genes. NirS and NirK were originally considered incompatible in most denitrifying organisms, although a few strains have been reported to possess both genes. Herein, we report the functional division of nirS and nirK in Thermus, a thermophilic genus widespread in thermal ecosystems. Transcriptional levels of nirS and nirK coexisting in Thermus antranikianii DSM 12462T were measured to assess the effects of nitrite, oxygen, and stimulation time. Thirty-nine Thermus strains were used to analyze the phylogeny and distribution of nirS and nirK; six representative strains were used to assess the denitrification phenotype. The results showed that both genes were actively transcribed and expressed independently in T. antranikianii DSM 12462T. Strains with both nirS and nirK had a wider range of nitrite adaptation and revealed nir-related physiological adaptations in Thermus: nirK facilitated adaptation to rapid changes and extended the adaptation range of nitrite under oxygen-limited conditions, while nirS expression was higher under oxic and relatively stable conditions.
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Affiliation(s)
- Rui-Rui Liu
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Ye Tian
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - En-Min Zhou
- School of Resource Environment and Earth Science, Yunnan Institute of Geography, Yunnan University, Kunming, 650091, People's Republic of China
| | - Meng-Jie Xiong
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Min Xiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.
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Verdú C, Sanchez E, Ortega C, Hidalgo A, Berenguer J, Mencía M. A Modular Vector Toolkit with a Tailored Set of Thermosensors To Regulate Gene Expression in Thermus thermophilus. ACS OMEGA 2019; 4:14626-14632. [PMID: 31528818 PMCID: PMC6740178 DOI: 10.1021/acsomega.9b02107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/14/2019] [Indexed: 05/02/2023]
Abstract
Modular plasmid architectures have shown to be a very useful resource to standardize, build, share, and compare biological parts and functional vectors, and are being applied in an increasing number of microorganisms. Here, we present a modular plasmid toolkit for Thermus thermophilus, a species considered as a workhorse for biotechnology and a model for high-temperature biology. Apart from integrating improved versions of already existing parts, we have characterized specific promoters and developed a thermosensor-based palette that restricts the expression to Thermus and, at the same time, controls protein expression in this organism in a temperature-dependent manner.
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Affiliation(s)
| | | | | | | | - José Berenguer
- E-mail: . Tel.: +34 911964498. Fax: +34 911964420 (J.B.)
| | - Mario Mencía
- E-mail: . Tel.: +34 911964664.
Fax: +34 911964420 (M.M.)
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Miralles-Robledillo JM, Torregrosa-Crespo J, Martínez-Espinosa RM, Pire C. DMSO Reductase Family: Phylogenetics and Applications of Extremophiles. Int J Mol Sci 2019; 20:E3349. [PMID: 31288391 PMCID: PMC6650914 DOI: 10.3390/ijms20133349] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 11/16/2022] Open
Abstract
Dimethyl sulfoxide reductases (DMSO) are molybdoenzymes widespread in all domains of life. They catalyse not only redox reactions, but also hydroxylation/hydration and oxygen transfer processes. Although literature on DMSO is abundant, the biological significance of these enzymes in anaerobic respiration and the molecular mechanisms beyond the expression of genes coding for them are still scarce. In this review, a deep revision of the literature reported on DMSO as well as the use of bioinformatics tools and free software has been developed in order to highlight the relevance of DMSO reductases on anaerobic processes connected to different biogeochemical cycles. Special emphasis has been addressed to DMSO from extremophilic organisms and their role in nitrogen cycle. Besides, an updated overview of phylogeny of DMSOs as well as potential applications of some DMSO reductases on bioremediation approaches are also described.
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Affiliation(s)
- Jose María Miralles-Robledillo
- Departamento de Agroquímica y Bioquímica, División de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Alicante, Carretera San Vicente del Raspeig s/n-03690 San Vicente del Raspeig, Alicante, Spain
| | - Javier Torregrosa-Crespo
- Departamento de Agroquímica y Bioquímica, División de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Alicante, Carretera San Vicente del Raspeig s/n-03690 San Vicente del Raspeig, Alicante, Spain
| | - Rosa María Martínez-Espinosa
- Departamento de Agroquímica y Bioquímica, División de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Alicante, Carretera San Vicente del Raspeig s/n-03690 San Vicente del Raspeig, Alicante, Spain
| | - Carmen Pire
- Departamento de Agroquímica y Bioquímica, División de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Alicante, Carretera San Vicente del Raspeig s/n-03690 San Vicente del Raspeig, Alicante, Spain.
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10
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Blesa A, Sánchez M, Sacristán-Horcajada E, González-de la Fuente S, Peiró R, Berenguer J. Into the Thermus Mobilome: Presence, Diversity and Recent Activities of Insertion Sequences Across Thermus spp. Microorganisms 2019; 7:microorganisms7010025. [PMID: 30669685 PMCID: PMC6352166 DOI: 10.3390/microorganisms7010025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/09/2019] [Accepted: 01/17/2019] [Indexed: 11/28/2022] Open
Abstract
A high level of transposon-mediated genome rearrangement is a common trait among microorganisms isolated from thermal environments, probably contributing to the extraordinary genomic plasticity and horizontal gene transfer (HGT) observed in these habitats. In this work, active and inactive insertion sequences (ISs) spanning the sequenced members of the genus Thermus were characterized, with special emphasis on three T. thermophilus strains: HB27, HB8, and NAR1. A large number of full ISs and fragments derived from different IS families were found, concentrating within megaplasmids present in most isolates. Potentially active ISs were identified through analysis of transposase integrity, and domestication-related transposition events of ISTth7 were identified in laboratory-adapted HB27 derivatives. Many partial copies of ISs appeared throughout the genome, which may serve as specific targets for homologous recombination contributing to genome rearrangement. Moreover, recruitment of IS1000 32 bp segments as spacers for CRISPR sequence was identified, pointing to the adaptability of these elements in the biology of these thermophiles. Further knowledge about the activity and functional diversity of ISs in this genus may contribute to the generation of engineered transposons as new genetic tools, and enrich our understanding of the outstanding plasticity shown by these thermophiles.
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Affiliation(s)
- Alba Blesa
- Department of Biotechnology, Faculty of Experimental Sciences, Universidad Francisco de Vitoria, Madrid 28223, Spain.
| | - Mercedes Sánchez
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
| | - Eva Sacristán-Horcajada
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
| | - Sandra González-de la Fuente
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
| | - Ramón Peiró
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid 28049, Spain.
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11
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Chahlafi Z, Alvarez L, Cava F, Berenguer J. The role of conserved proteins DrpA and DrpB in nitrate respiration of Thermus thermophilus. Environ Microbiol 2018; 20:3851-3861. [PMID: 30187633 PMCID: PMC6282519 DOI: 10.1111/1462-2920.14400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/03/2018] [Accepted: 08/27/2018] [Indexed: 12/26/2022]
Abstract
In many Thermus thermophilus strains, nitrate respiration is encoded in mobile genetic regions, along with regulatory circuits that modulate its expression based on anoxia and nitrate presence. The oxygen-responsive system has been identified as the product of the dnrST (dnr) operon located immediately upstream of the nar operon (narCGHJIKT), which encodes the nitrate reductase (NR) and nitrate/nitrite transporters. In contrast, the nature of the nitrate sensory system is not known. Here, we analyse the putative nitrate-sensing role of the bicistronic drp operon (drpAB) present downstream of the nar operon in most denitrifying Thermus spp. Expression of drp was found to depend on the master regulator DnrT, whereas the absence of DrpA or DrpB increased the expression of both DnrS and DnrT and, concomitantly, of the NR. Absence of both proteins made expression from the dnr and nar operons independent of nitrate. Polyclonal antisera allowed us to identify DrpA as a periplasmic protein and DrpB as a membrane protein, with capacity to bind to the cytoplasmic membrane. Here, we propose a role for DrpA/DrpB as nitrate sensors during denitrification.
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Affiliation(s)
- Zahra Chahlafi
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, 28049, Spain
| | - Laura Alvarez
- Department of Molecular Biology, Umeå University, Umeå, 901 87, Sweden
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, Umeå, 901 87, Sweden
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, 28049, Spain
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Alvarez L, Sanchez-Hevia D, Sánchez M, Berenguer J. A new family of nitrate/nitrite transporters involved in denitrification. Int Microbiol 2018; 22:19-28. [PMID: 30810929 PMCID: PMC6394727 DOI: 10.1007/s10123-018-0023-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 11/29/2022]
Abstract
Denitrifying bacteria carry out nitrate and nitrite respiration inside and outside the cell, respectively. In Thermus thermophilus, nitrate and nitrite transport processes are carried out by major facilitator superfamily (MFS) transporters. The sequence of the nar operon of nitrate-only respiring strains of T. thermophilus includes two tandemly organized MFS transporter genes (narK and narT) of the NarK1 and NarK2 families. Both can function as nitrate/nitrite antiporters, but NarK has been proposed as more specific for nitrate whereas NarT more specific for nitrite. In some nitrate- and nitrite-respiring strains of the same species, a single MFS transporter (NarO) belonging to a different MFS subfamily appears. To analyze the role of this single MFS in the same genetic context, we transferred the two types of nar operon to the aerobic strain HB27, and further included in both of them the ability to respire nitrite. The new denitrifying strains HB27dn, with two MFS, and HB27dp, with a single one, were used to isolate mutants devoid of transporters. Through in trans complementation experiments, we demonstrate that the NarO single MFS works efficiently in the transport of both nitrate and nitrite.
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Affiliation(s)
- Laura Alvarez
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid- Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, 90187, Umeå, Sweden
| | - Dione Sanchez-Hevia
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid- Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
| | - Mercedes Sánchez
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid- Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid- Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain.
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Antonucci I, Gallo G, Limauro D, Contursi P, Ribeiro AL, Blesa A, Berenguer J, Bartolucci S, Fiorentino G. Characterization of a promiscuous cadmium and arsenic resistance mechanism in Thermus thermophilus HB27 and potential application of a novel bioreporter system. Microb Cell Fact 2018; 17:78. [PMID: 29776370 PMCID: PMC5960188 DOI: 10.1186/s12934-018-0918-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/03/2018] [Indexed: 11/21/2022] Open
Abstract
Background The characterization of the molecular determinants of metal resistance has potential biotechnological application in biosensing and bioremediation. In this context, the bacterium Thermus thermophilus HB27 is a metal tolerant thermophile containing a set of genes involved in arsenic resistance which, differently from other microbes, are not organized into a single operon. They encode the proteins: arsenate reductase, TtArsC, arsenic efflux membrane transporter, TtArsX, and transcriptional repressor, TtSmtB. Results In this work we show that the arsenic efflux protein TtArsX and the arsenic responsive transcriptional repressor TtSmtB are required to provide resistance to cadmium. We analyzed the sensitivity to Cd(II) of mutants lacking TtArsX, finding that they are more sensitive to this metal than the wild type strain. In addition, using promoter probe reporter plasmids, we show that the transcription of TtarsX is also stimulated by the presence of Cd(II) in a TtSmtB-dependent way. Actually, a regulatory circuit composed of TtSmtB and a reporter gene expressed from the TtarsX promoter responds to variation in Cd(II), As(III) and As(V) concentrations. Conclusions Our results demonstrate that the system composed by TtSmtB and TtArsX is responsible for both the arsenic and cadmium resistance in T. thermophilus. The data also support the use of T. thermophilus as a suitable chassis for the design and development of As-Cd biosensors. Electronic supplementary material The online version of this article (10.1186/s12934-018-0918-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Immacolata Antonucci
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy
| | - Giovanni Gallo
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy
| | - Danila Limauro
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy
| | - Patrizia Contursi
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy
| | - Ana Luisa Ribeiro
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Alba Blesa
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Campus Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Simonetta Bartolucci
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy
| | - Gabriella Fiorentino
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy.
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Abstract
This chapter provides an overview of current knowledge of how anaerobic bacteria protect themselves against nitrosative stress. Nitric oxide (NO) is the primary source of this stress. Aerobically its removal is an oxidative process, whereas reduction is required anaerobically. Mechanisms required to protect aerobic and anaerobic bacteria are therefore different. Several themes recur in the review. First, how gene expression is regulated often provides clues to the physiological function of the gene products. Second, the physiological significance of reports based upon experiments under extreme conditions that bacteria do not encounter in their natural environment requires reassessment. Third, responses to the primary source of stress need to be distinguished from secondary consequences of chemical damage due to failure of repair mechanisms to cope with extreme conditions. NO is generated by many mechanisms, some of which remain undefined. An example is the recent demonstration that the hybrid cluster protein combines with YtfE (or RIC protein, for repair of iron centres damaged by nitrosative stress) in a new pathway to repair key iron-sulphur proteins damaged by nitrosative stress. The functions of many genes expressed in response to nitrosative stress remain either controversial or are completely unknown. The concentration of NO that accumulates in the bacterial cytoplasm is essentially unknown, so dogmatic statements cannot be made that damage to transcription factors (Fur, FNR, SoxRS, MelR, OxyR) occurs naturally as part of a physiologically relevant signalling mechanism. Such doubts can be resolved by simple experiments to meet six proposed criteria.
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15
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Alvarez L, Quintáns NG, Blesa A, Baquedano I, Mencía M, Bricio C, Berenguer J. Hierarchical Control of Nitrite Respiration by Transcription Factors Encoded within Mobile Gene Clusters of Thermus thermophilus. Genes (Basel) 2017; 8:genes8120361. [PMID: 29194386 PMCID: PMC5748679 DOI: 10.3390/genes8120361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/23/2017] [Accepted: 11/29/2017] [Indexed: 11/16/2022] Open
Abstract
Denitrification in Thermus thermophilus is encoded by the nitrate respiration conjugative element (NCE) and nitrite and nitric oxide respiration (nic) gene clusters. A tight coordination of each cluster’s expression is required to maximize anaerobic growth, and to avoid toxicity by intermediates, especially nitric oxides (NO). Here, we study the control of the nitrite reductases (Nir) and NO reductases (Nor) upon horizontal acquisition of the NCE and nic clusters by a formerly aerobic host. Expression of the nic promoters PnirS, PnirJ, and PnorC, depends on the oxygen sensor DnrS and on the DnrT protein, both NCE-encoded. NsrR, a nic-encoded transcription factor with an iron–sulfur cluster, is also involved in Nir and Nor control. Deletion of nsrR decreased PnorC and PnirJ transcription, and activated PnirS under denitrification conditions, exhibiting a dual regulatory role never described before for members of the NsrR family. On the basis of these results, a regulatory hierarchy is proposed, in which under anoxia, there is a pre-activation of the nic promoters by DnrS and DnrT, and then NsrR leads to Nor induction and Nir repression, likely as a second stage of regulation that would require NO detection, thus avoiding accumulation of toxic levels of NO. The whole system appears to work in remarkable coordination to function only when the relevant nitrogen species are present inside the cell.
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Affiliation(s)
- Laura Alvarez
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
- Current Address: Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden.
| | - Nieves G Quintáns
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
| | - Alba Blesa
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
| | - Ignacio Baquedano
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
| | - Mario Mencía
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
| | - Carlos Bricio
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
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16
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Vettone A, Serpe M, Hidalgo A, Berenguer J, del Monaco G, Valenti A, Rossi M, Ciaramella M, Perugino G. A novel thermostable protein-tag: optimization of the Sulfolobus solfataricus DNA- alkyl-transferase by protein engineering. Extremophiles 2016; 20:1-13. [PMID: 26499124 DOI: 10.1007/s00792-015-0791-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/03/2015] [Indexed: 12/12/2022]
Abstract
In the last decade, a powerful biotechnological tool for the in vivo and in vitro specific labeling of proteins (SNAP-tag™ technology) was proposed as a valid alternative to classical protein-tags (green fluorescent proteins, GFPs). This was made possible by the discovery of the irreversible reaction of the human alkylguanine-DNA-alkyl-transferase (hAGT) in the presence of benzyl-guanine derivatives. However, the mild reaction conditions and the general instability of the mesophilic SNAP-tag™ make this new approach not fully applicable to (hyper-)thermophilic and, in general, extremophilic organisms. Here, we introduce an engineered variant of the thermostable alkylguanine-DNA-alkyl-transferase from the Archaea Sulfolobus solfataricus (SsOGT-H5), which displays a catalytic efficiency comparable to the SNAP-tag™ protein, but showing high intrinsic stability typical of proteins from this organism. The successful heterologous expression obtained in a thermophilic model organism makes SsOGT-H5 a valid candidate as protein-tag for organisms living in extreme environments.
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Affiliation(s)
- Antonella Vettone
- Institute of Biosciences and BioResources, National Council of Research of Italy, Via P. Castellino 111, 80131 Naples, Italy
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17
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Zhou EM, Murugapiran SK, Mefferd CC, Liu L, Xian WD, Yin YR, Ming H, Yu TT, Huntemann M, Clum A, Pillay M, Palaniappan K, Varghese N, Mikhailova N, Stamatis D, Reddy TBK, Ngan CY, Daum C, Shapiro N, Markowitz V, Ivanova N, Spunde A, Kyrpides N, Woyke T, Li WJ, Hedlund BP. High-quality draft genome sequence of the Thermus amyloliquefaciens type strain YIM 77409(T) with an incomplete denitrification pathway. Stand Genomic Sci 2016; 11:20. [PMID: 26925197 PMCID: PMC4769583 DOI: 10.1186/s40793-016-0140-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/10/2015] [Indexed: 11/25/2022] Open
Abstract
Thermus amyloliquefaciens type strain YIM 77409(T) is a thermophilic, Gram-negative, non-motile and rod-shaped bacterium isolated from Niujie Hot Spring in Eryuan County, Yunnan Province, southwest China. In the present study we describe the features of strain YIM 77409(T) together with its genome sequence and annotation. The genome is 2,160,855 bp long and consists of 6 scaffolds with 67.4 % average GC content. A total of 2,313 genes were predicted, comprising 2,257 protein-coding and 56 RNA genes. The genome is predicted to encode a complete glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle. Additionally, a large number of transporters and enzymes for heterotrophy highlight the broad heterotrophic lifestyle of this organism. A denitrification gene cluster included genes predicted to encode enzymes for the sequential reduction of nitrate to nitrous oxide, consistent with the incomplete denitrification phenotype of this strain.
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Affiliation(s)
- En-Min Zhou
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
- />School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV USA
| | | | | | - Lan Liu
- />State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275 People’s Republic of China
| | - Wen-Dong Xian
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Yi-Rui Yin
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Hong Ming
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Tian-Tian Yu
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
| | - Marcel Huntemann
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Alicia Clum
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Manoj Pillay
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | | | - Neha Varghese
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | | | | | - T. B. K. Reddy
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Chew Yee Ngan
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Chris Daum
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Nicole Shapiro
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Victor Markowitz
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Natalia Ivanova
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Alexander Spunde
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Nikos Kyrpides
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Tanja Woyke
- />Department of Energy Joint Genome Institute, Walnut Creek, CA USA
| | - Wen-Jun Li
- />Yunnan Institute of Microbiology, Yunnan University, Kunming, 650091 People’s Republic of China
- />State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, College of Ecology and Evolution, Sun Yat-Sen University, Guangzhou, 510275 People’s Republic of China
| | - Brian P. Hedlund
- />School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV USA
- />Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV USA
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18
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Noncanonical cell-to-cell DNA transfer in Thermus spp. is insensitive to argonaute-mediated interference. J Bacteriol 2014; 197:138-46. [PMID: 25331432 DOI: 10.1128/jb.02113-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Horizontal gene transfer drives the rapid evolution of bacterial populations. Classical processes that promote the lateral flow of genetic information are conserved throughout the prokaryotic world. However, some species have nonconserved transfer mechanisms that are not well known. This is the case for the ancient extreme thermophile Thermus thermophilus. In this work, we show that T. thermophilus strains are capable of exchanging large DNA fragments by a novel mechanism that requires cell-to-cell contacts and employs components of the natural transformation machinery. This process facilitates the bidirectional transfer of virtually any DNA locus but favors by 10-fold loci found in the megaplasmid over those in the chromosome. In contrast to naked DNA acquisition by transformation, the system does not activate the recently described DNA-DNA interference mechanism mediated by the prokaryotic Argonaute protein, thus allowing the organism to distinguish between DNA transferred from a mate and exogenous DNA acquired from unknown hosts. This Argonaute-mediated discrimination may be tentatively viewed as a strategy for safe sharing of potentially "useful" traits by the components of a given population of Thermus spp. without increasing the genome sizes of its individuals.
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19
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A third subunit in ancestral cytochrome c-dependent nitric oxide reductases. Appl Environ Microbiol 2014; 80:4871-8. [PMID: 24907324 DOI: 10.1128/aem.00790-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reduction of NO to N2O by denitrifiying bacteria is catalyzed either by a monomeric quinol-nitric oxide reductase (qNor) or by a heterodimeric cytochrome c-dependent nitric oxide reductase (cNor). In ancient thermophilic bacteria belonging to the Thermales and Aquificales phylogenetic groups, the cluster encoding the cNor includes a small third gene (norH), in addition to those encoding homologues to the subunits of a typical cNor (norC and norB). We show in Thermus thermophilus that the three genes are cotranscribed in a single mRNA from an inducible promoter. The isolation of individual nor mutants and the production in vivo of His-tagged NorH protein followed by immobilized-metal affinity chromatography (IMAC) allowed us to conclude that NorH constitutes a third subunit of the cNor from T. thermophilus, which is involved in denitrification in vivo, likely allowing more efficient electron transport to cNor.
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20
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Swarts DC, Jore MM, Westra ER, Zhu Y, Janssen JH, Snijders AP, Wang Y, Patel DJ, Berenguer J, Brouns SJJ, van der Oost J. DNA-guided DNA interference by a prokaryotic Argonaute. Nature 2014; 507:258-261. [PMID: 24531762 DOI: 10.1038/nature12971] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 12/19/2013] [Indexed: 12/19/2022]
Abstract
RNA interference is widely distributed in eukaryotes and has a variety of functions, including antiviral defence and gene regulation. All RNA interference pathways use small single-stranded RNA (ssRNA) molecules that guide proteins of the Argonaute (Ago) family to complementary ssRNA targets: RNA-guided RNA interference. The role of prokaryotic Ago variants has remained elusive, although bioinformatics analysis has suggested their involvement in host defence. Here we demonstrate that Ago of the bacterium Thermus thermophilus (TtAgo) acts as a barrier for the uptake and propagation of foreign DNA. In vivo, TtAgo is loaded with 5'-phosphorylated DNA guides, 13-25 nucleotides in length, that are mostly plasmid derived and have a strong bias for a 5'-end deoxycytidine. These small interfering DNAs guide TtAgo to cleave complementary DNA strands. Hence, despite structural homology to its eukaryotic counterparts, TtAgo functions in host defence by DNA-guided DNA interference.
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Affiliation(s)
- Daan C Swarts
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - Matthijs M Jore
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - Edze R Westra
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - Yifan Zhu
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - Jorijn H Janssen
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - Ambrosius P Snijders
- Clare Hall Laboratories, Cancer Research UK, London Research Institute, South Mimms EN6 3LD, UK
| | - Yanli Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - José Berenguer
- Centro de Biología Molecular Severo Ochoa, UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Stan J J Brouns
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, the Netherlands
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21
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Parallel pathways for nitrite reduction during anaerobic growth in Thermus thermophilus. J Bacteriol 2014; 196:1350-8. [PMID: 24443532 DOI: 10.1128/jb.01042-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Respiratory reduction of nitrate and nitrite is encoded in Thermus thermophilus by the respective transferable gene clusters. Nitrate is reduced by a heterotetrameric nitrate reductase (Nar) encoded along transporters and regulatory signal transduction systems within the nitrate respiration conjugative element (NCE). The nitrite respiration cluster (nic) encodes homologues of nitrite reductase (Nir) and nitric oxide reductase (Nor). The expression and role of the nirSJM genes in nitrite respiration were analyzed. The three genes are expressed from two promoters, one (nirSp) producing a tricistronic mRNA under aerobic and anaerobic conditions and the other (nirJp) producing a bicistronic mRNA only under conditions of anoxia plus a nitrogen oxide. As for its nitrite reductase homologues, NirS is expressed in the periplasm, has a covalently bound heme c, and conserves the heme d1 binding pocket. NirJ is a cytoplasmic protein likely required for heme d1 synthesis and NirS maturation. NirM is a soluble periplasmic homologue of cytochrome c552. Mutants defective in nirS show normal anaerobic growth with nitrite and nitrate, supporting the existence of an alternative Nir in the cells. Gene knockout analysis of different candidate genes did not allow us to identify this alternative Nir protein but revealed the requirement for Nar in NirS-dependent and NirS-independent nitrite reduction. As the likely role for Nar in the process is in electron transport through its additional cytochrome c periplasmic subunit (NarC), we concluded all the Nir activity takes place in the periplasm by parallel pathways.
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22
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Lin L, Xu J. Dissecting and engineering metabolic and regulatory networks of thermophilic bacteria for biofuel production. Biotechnol Adv 2013; 31:827-37. [DOI: 10.1016/j.biotechadv.2013.03.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/06/2013] [Accepted: 03/10/2013] [Indexed: 01/08/2023]
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23
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Abstract
Laboratory-adapted strains of Thermus spp. have been shown to require oxygen for growth, including the model strains T. thermophilus HB27 and HB8. In contrast, many isolates of this species that have not been intensively grown under laboratory conditions keep the capability to grow anaerobically with one or more electron acceptors. The use of nitrogen oxides, especially nitrate, as electron acceptors is one of the most widespread capabilities among these facultative strains. In this process, nitrate is reduced to nitrite by a reductase (Nar) that also functions as electron transporter toward nitrite and nitric oxide reductases when nitrate is scarce, effectively replacing respiratory complex III. In many T. thermophilus denitrificant strains, most electrons for Nar are provided by a new class of NADH dehydrogenase (Nrc). The ability to reduce nitrite to NO and subsequently to N2O by the corresponding Nir and Nor reductases is also strain specific. The genes encoding the capabilities for nitrate (nar) and nitrite (nir and nor) respiration are easily transferred between T. thermophilus strains by natural competence or by a conjugation-like process and may be easily lost upon continuous growth under aerobic conditions. The reason for this instability is apparently related to the fact that these metabolic capabilities are encoded in gene cluster islands, which are delimited by insertion sequences and integrated within highly variable regions of easily transferable extrachromosomal elements. Together with the chromosomal genes, these plasmid-associated genetic islands constitute the extended pangenome of T. thermophilus that provides this species with an enhanced capability to adapt to changing environments.
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24
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Murugapiran SK, Huntemann M, Wei CL, Han J, Detter JC, Han C, Erkkila TH, Teshima H, Chen A, Kyrpides N, Mavrommatis K, Markowitz V, Szeto E, Ivanova N, Pagani I, Pati A, Goodwin L, Peters L, Pitluck S, Lam J, McDonald AI, Dodsworth JA, Woyke T, Hedlund BP. Thermus oshimai JL-2 and T. thermophilus JL-18 genome analysis illuminates pathways for carbon, nitrogen, and sulfur cycling. Stand Genomic Sci 2013; 7:449-68. [PMID: 24019992 PMCID: PMC3764938 DOI: 10.4056/sigs.3667269] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The complete genomes of Thermus oshimai JL-2 and T. thermophilus JL-18 each consist of a circular chromosome, 2.07 Mb and 1.9 Mb, respectively, and two plasmids ranging from 0.27 Mb to 57.2 kb. Comparison of the T. thermophilus JL-18 chromosome with those from other strains of T. thermophilus revealed a high degree of synteny, whereas the megaplasmids from the same strains were highly plastic. The T. oshimai JL-2 chromosome and megaplasmids shared little or no synteny with other sequenced Thermus strains. Phylogenomic analyses using a concatenated set of conserved proteins confirmed the phylogenetic and taxonomic assignments based on 16S rRNA phylogenetics. Both chromosomes encode a complete glycolysis, tricarboxylic acid (TCA) cycle, and pentose phosphate pathway plus glucosidases, glycosidases, proteases, and peptidases, highlighting highly versatile heterotrophic capabilities. Megaplasmids of both strains contained a gene cluster encoding enzymes predicted to catalyze the sequential reduction of nitrate to nitrous oxide; however, the nitrous oxide reductase required for the terminal step in denitrification was absent, consistent with their incomplete denitrification phenotypes. A sox gene cluster was identified in both chromosomes, suggesting a mode of chemolithotrophy. In addition, nrf and psr gene clusters in T. oshmai JL-2 suggest respiratory nitrite ammonification and polysulfide reduction as possible modes of anaerobic respiration.
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25
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Partial and complete denitrification in Thermus thermophilus: lessons from genome drafts. Biochem Soc Trans 2011; 39:249-53. [PMID: 21265782 DOI: 10.1042/bst0390249] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have obtained draft genomic sequences of PD (partial denitrificant) and CD (complete denitrificant) strains of Thermus thermophilus. Their genomes are similar in size to that of the aerobic strains sequenced to date and probably contain a similar megaplasmid. In the CD strain, the genes encoding a putative cytochrome cd1 Nir (nitrite reductase) and ancillary proteins were clustered with a cytochrome c-dependent Nor (nitric oxide reductase), and with genes that are probably implicated in their regulation. The Nar (nitrate reductase) and associated genes were also clustered and located 7 kb downstream of the genes coding for the Nir. The whole nar-nir-nor denitrification supercluster was identified as part of a variable region of a megaplasmid. No homologues of NosZ were found despite nitrogen balance supports the idea that such activity actually exists.
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Lateral transfer of the denitrification pathway genes among Thermus thermophilus strains. Appl Environ Microbiol 2010; 77:1352-8. [PMID: 21169443 DOI: 10.1128/aem.02048-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrate respiration is a common and strain-specific property in Thermus thermophilus encoded by the nitrate respiration conjugative element (NCE) that can be laterally transferred by conjugation. In contrast, nitrite respiration and further denitrification steps are restricted to a few isolates of this species. These later steps of the denitrification pathway are under the regulatory control of an NCE-encoded transcription factor, but nothing is known about their coding sequences or its putative genetic linkage to the NCE. In this study we examine the genetic linkage between nitrate and nitrite respiration through lateral gene transfer (LGT) assays and describe a cluster of genes encoding the nitrite-nitric oxide respiration in T. thermophilus PRQ25. We show that the whole denitrification pathway can be transferred from the denitrificant strain PRQ25 to an aerobic strain, HB27, and that the genes coding for nitrite and nitric oxide respiration are encoded near the NCE. Sequence data from the draft genome of PRQ25 confirmed these results and allowed us to describe the most compact nor-nir cluster known thus far and to demonstrate the expression and activities of the encoded enzymes in the HB27 denitrificant derivatives obtained by LGT. We conclude that this NCE nor-nir supercluster constitutes a whole denitrification island that can be spread by lateral transfer among Thermus thermophilus strains.
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Thermus thermophilus as biological model. Extremophiles 2009; 13:213-31. [DOI: 10.1007/s00792-009-0226-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Accepted: 12/31/2008] [Indexed: 10/21/2022]
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Common thiolation mechanism in the biosynthesis of tRNA thiouridine and sulphur-containing cofactors. EMBO J 2008; 27:3267-78. [PMID: 19037260 DOI: 10.1038/emboj.2008.246] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 11/04/2008] [Indexed: 11/08/2022] Open
Abstract
2-Thioribothymidine (s(2)T), a modified uridine, is found at position 54 in transfer RNAs (tRNAs) from several thermophiles; s(2)T stabilizes the L-shaped structure of tRNA and is essential for growth at higher temperatures. Here, we identified an ATPase (tRNA-two-thiouridine C, TtuC) required for the 2-thiolation of s(2)T in Thermus thermophilus and examined in vitro s(2)T formation by TtuC and previously identified s(2)T-biosynthetic proteins (TtuA, TtuB, and cysteine desulphurases). The C-terminal glycine of TtuB is first activated as an acyl-adenylate by TtuC and then thiocarboxylated by cysteine desulphurases. The sulphur atom of thiocarboxylated TtuB is transferred to tRNA by TtuA. In a ttuC mutant of T. thermophilus, not only s(2)T, but also molybdenum cofactor and thiamin were not synthesized, suggesting that TtuC is shared among these biosynthetic pathways. Furthermore, we found that a TtuB-TtuC thioester was formed in vitro, which was similar to the ubiquitin-E1 thioester, a key intermediate in the ubiquitin system. The results are discussed in relation to the mechanism and evolution of the eukaryotic ubiquitin system.
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Cava F, Zafra O, Berenguer J. A cytochrome c containing nitrate reductase plays a role in electron transport for denitrification in Thermus thermophilus without involvement of the bc respiratory complex. Mol Microbiol 2008; 70:507-18. [PMID: 18761683 DOI: 10.1111/j.1365-2958.2008.06429.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bc(1) respiratory complex III constitutes a key energy-conserving respiratory electron transporter between complex I (type I NADH dehydrogenase) and II (succinate dehydrogenase) and the final nitrogen oxide reductases (Nir, Nor and Nos) in most denitrifying bacteria. However, we show that the expression of complex III from Thermus thermophilus is repressed under denitrification, and that its role as electron transporter is replaced by an unusual nitrate reductase (Nar) that contains a periplasmic cytochrome c (NarC). Several lines of evidence support this conclusion: (i) nitrite and NO are as effective signals as nitrate for the induction of Nar; (ii) narC mutants are defective in anaerobic growth with nitrite, NO and N2O; (iii) such mutants present decreased NADH oxidation coupled to these electron acceptors; and (iv) complementation assays of the mutants reveal that the membrane-distal heme c of NarC was necessary for anaerobic growth with nitrite, whereas the membrane-proximal heme c was not. Finally, we show evidence to support that Nrc, the main NADH oxidative activity in denitrification, interacts with Nar through their respective membrane subunits. Thus, we propose the existence of a Nrc-Nar respiratory super-complex that is required for the development of the whole denitrification pathway in T. thermophilus.
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Affiliation(s)
- Felipe Cava
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Campus U.A.M. 28049-Madrid, Spain
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Cava F, de Pedro MA, Blas-Galindo E, Waldo GS, Westblade LF, Berenguer J. Expression and use of superfolder green fluorescent protein at high temperatures in vivo: a tool to study extreme thermophile biology. Environ Microbiol 2008; 10:605-13. [DOI: 10.1111/j.1462-2920.2007.01482.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cava F, Zafra O, da Costa MS, Berenguer J. The role of the nitrate respiration element of Thermus thermophilus in the control and activity of the denitrification apparatus. Environ Microbiol 2008; 10:522-33. [DOI: 10.1111/j.1462-2920.2007.01472.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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