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Abstract
Background Group II introns are mobile genetic elements used as efficient gene targeting tools. They function as both ribozymes and retroelements. Group IIC introns are the only class reported so far to be associated with integrons. In order to identify group II introns linked with integrons and CALINS (cluster of attC sites lacking a neighboring integron integrase) within halophiles, we mined for integrons in 28 assembled metagenomes from hypersaline environments and publically available 104 halophilic genomes using Integron Finder followed by blast search for group II intron reverse transcriptases (RT)s. Results We report the presence of different group II introns associated with integrons and integron-related sequences denoted by UHB.F1, UHB.I2, H.ha.F1 and H.ha.F2. The first two were identified within putative integrons in the metagenome of Tanatar-5 hypersaline soda lake, belonging to IIC and IIB intron classes, respectively at which the first was a truncated intron. Other truncated introns H.ha.F1 and H.ha.F2 were also detected in a CALIN within the extreme halophile Halorhodospira halochloris, both belonging to group IIB introns. The intron-encoded proteins (IEP) s identified within group IIB introns belonged to different classes: CL1 class in UHB.I2 and bacterial class E in H.ha.Fa1 and H.ha.F2. A newly identified insertion sequence (ISHahl1) of IS200/605 superfamily was also identified adjacent to H. halochloris CALIN. Finally, an abundance of toxin-antitoxin (TA) systems was observed within the identified integrons. Conclusion So far, this is the first investigation of group II introns within integrons in halophilic genomes and metagenomes from hypersaline environments. We report the presence of group IIB introns associated with integrons or CALINs. This study provides the basis for understanding the role of group IIB introns in the evolution of halophiles and their potential biotechnological role. Supplementary Information The online version contains supplementary material available at 10.1186/s13100-021-00234-2.
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Affiliation(s)
- Sarah Sonbol
- Biology Department and the Graduate Program of Biotechnology, School of Sciences and Engineering, the American University in Cairo, New Cairo, Cairo, 11835, Egypt
| | - Rania Siam
- Biology Department and the Graduate Program of Biotechnology, School of Sciences and Engineering, the American University in Cairo, New Cairo, Cairo, 11835, Egypt. .,University of Medicine and Health Sciences, Basseterre, Saint Kitts and Nevis.
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Zheng X, Liu W, Dai X, Zhu Y, Wang J, Zhu Y, Zheng H, Huang Y, Dong Z, Du W, Zhao F, Huang L. Extraordinary diversity of viruses in deep-sea sediments as revealed by metagenomics without prior virion separation. Environ Microbiol 2020; 23:728-743. [PMID: 32627268 DOI: 10.1111/1462-2920.15154] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/03/2020] [Indexed: 12/18/2022]
Abstract
Our current knowledge of the virosphere in deep-sea sediments remains rudimentary. Here we investigated viral diversity at both gene and genomic levels in deep-sea sediments of Southwest Indian Ocean. Analysis of 19 676 106 non-redundant genes from the metagenomic DNA sequences revealed a large number of unclassified viral groups in these samples. A total of 1106 high-confidence viral contigs were obtained after two runs of assemblies, and 217 of these contigs with sizes up to ~120 kb were shown to represent complete viral genomes. These contigs are clustered with no known viral genomes, and over 2/3 of the ORFs on the viral contigs encode no known functions. Furthermore, most of the complete viral contigs show limited similarity to known viral genomes in genome organization. Most of the classified viral contigs are derived from dsDNA viruses belonging to the order Caudovirales, including primarily members of the families Myoviridae, Podoviridae and Siphoviridae. Most of these viruses infect Proteobacteria and, less frequently, Planctomycetes, Firmicutes, Chloroflexi, etc. Auxiliary metabolic genes (AMGs), present in abundance on the viral contigs, appear to function in modulating the host ability to sense environmental gradients and community changes, and to uptake and metabolize nutrients.
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Affiliation(s)
- Xiaowei Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xin Dai
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yaxin Zhu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jinfeng Wang
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yongqiang Zhu
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, 201203, China
| | - Huajun Zheng
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, 201203, China
| | - Ying Huang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wenbin Du
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fangqing Zhao
- Computational Genomics Lab, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Huang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
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AbdelWahed MG, Badiea EA, Ouf A, Sayed AA. Molecular and functional characterization of unique thermo-halophilic thioredoxin from the metagenome of an exotic environment. Int J Biol Macromol 2020; 153:767-778. [PMID: 32142845 DOI: 10.1016/j.ijbiomac.2020.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 11/30/2022]
Abstract
The lower convective layer (LCL) at Atlantis II brine pool of the Red sea represents one of the exceptional, unique ecosystems. Thioredoxin is a multi-functional antioxidant redox protein that has a crucial role in various vital cellular processes. In the current study, a functional metagenomics approach was used to isolate and characterize thioredoxin from the LCL of Atlantis II Deep brine pool (Trx-ATII). From the metagenomic DNA of the LCL, the thioredoxin gene was directly retrieved and sequenced. Sequence analysis showed that the gene belonged to thioredoxin-like superfamily with classical Trx motif (-CXXC-). Phylogenetic analysis revealed that Trx-ATII was closely related to Trx of Prochlorococcus marinus with a maximum identity of 86%. Successfully, Trx-ATII was cloned and expressed in E. coli, where the purified protein had M.wt of 16 kDa. Characterization studies revealed that Trx-ATII protein is halophilic; can tolerate up to 2.5 M NaCl and thermostable, where 90% of its activity was retained at 60 °C. Trx-ATII can reduce both DTNB and insulin disulfide- containing substrates. In conclusion, a unique thioredoxin protein was isolated from a harsh environment that can maintain its activity under extreme conditions of salinity and temperature as a promising redox protein for biotechnological applications.
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Affiliation(s)
| | - Elham A Badiea
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Amged Ouf
- Biology Department, American University in Cairo, Egypt
| | - Ahmed A Sayed
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt; Children Cancer Hospital, 57357 Cairo, Egypt.
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Badiea EA, Sayed AA, Maged M, Fouad WM, Said MM, Esmat AY. A novel thermostable and halophilic thioredoxin reductase from the Red Sea Atlantis II hot brine pool. PLoS One 2019; 14:e0217565. [PMID: 31150456 PMCID: PMC6544261 DOI: 10.1371/journal.pone.0217565] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/14/2019] [Indexed: 11/19/2022] Open
Abstract
The highly extreme conditions of the lower convective layer in the Atlantis II (ATII) Deep brine pool of the Red Sea make it an ideal environment for the search for novel enzymes that can function under extreme conditions. In the current study, we isolated a novel sequence of a thioredoxin reductase (TrxR) enzyme from the metagenomic dataset established from the microbial community that resides in the lower convective layer of Atlantis II. The gene was cloned, expressed and characterized for redox activity, halophilicity, and thermal stability. The isolated thioredoxin reductase (ATII-TrxR) was found to belong to the high-molecular-weight class of thioredoxin reductases. A search for conserved domains revealed the presence of an extra domain (Crp) in the enzyme sequence. Characterization studies of ATII-TrxR revealed that the enzyme was halophilic (maintained activity at 4 M NaCl), thermophilic (optimum temperature was 65°C) and thermostable (60% of its activity was retained at 70°C). Additionally, the enzyme utilized NADH in addition to NADPH as an electron donor. In conclusion, a novel thermostable and halophilic thioredoxin reductase has been isolated with a unique sequence that adapts to the harsh conditions of the brine pools making this protein a good candidate for biological research and industrial applications.
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Affiliation(s)
- Elham A. Badiea
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
- Department of Biology, School of Sciences and Engineering, American University in Cairo, New Cairo, Egypt
| | - Ahmed A. Sayed
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
- Children Cancer Hospital, Cairo, Egypt
| | - Mohamad Maged
- Faculty of Biotechnology, October University for Modern Sciences and Arts, 6th October City, Cairo, Egypt
| | - Walid M. Fouad
- Department of Biology, School of Sciences and Engineering, American University in Cairo, New Cairo, Egypt
| | - Mahmoud M. Said
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Amr Y. Esmat
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
- * E-mail:
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Ziko L, Adel M, Malash MN, Siam R. Insights into Red Sea Brine Pool Specialized Metabolism Gene Clusters Encoding Potential Metabolites for Biotechnological Applications and Extremophile Survival. Mar Drugs 2019; 17:md17050273. [PMID: 31071993 PMCID: PMC6562949 DOI: 10.3390/md17050273] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/12/2019] [Accepted: 04/19/2019] [Indexed: 12/21/2022] Open
Abstract
The recent rise in antibiotic and chemotherapeutic resistance necessitates the search for novel drugs. Potential therapeutics can be produced by specialized metabolism gene clusters (SMGCs). We mined for SMGCs in metagenomic samples from Atlantis II Deep, Discovery Deep and Kebrit Deep Red Sea brine pools. Shotgun sequence assembly and secondary metabolite analysis shell (antiSMASH) screening unraveled 2751 Red Sea brine SMGCs, pertaining to 28 classes. Predicted categorization of the SMGC products included those (1) commonly abundant in microbes (saccharides, fatty acids, aryl polyenes, acyl-homoserine lactones), (2) with antibacterial and/or anticancer effects (terpenes, ribosomal peptides, non-ribosomal peptides, polyketides, phosphonates) and (3) with miscellaneous roles conferring adaptation to the environment/special structure/unknown function (polyunsaturated fatty acids, ectoine, ladderane, others). Saccharide (80.49%) and putative (7.46%) SMGCs were the most abundant. Selected Red Sea brine pool sites had distinct SMGC profiles, e.g., for bacteriocins and ectoine. Top promising candidates, SMs with pharmaceutical applications, were addressed. Prolific SM-producing phyla (Proteobacteria, Actinobacteria, Cyanobacteria), were ubiquitously detected. Sites harboring the largest numbers of bacterial and archaeal phyla, had the most SMGCs. Our results suggest that the Red Sea brine niche constitutes a rich biological mine, with the predicted SMs aiding extremophile survival and adaptation.
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Affiliation(s)
- Laila Ziko
- Graduate Program of Biotechnology, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo 11835, Egypt.
| | - Mustafa Adel
- Graduate Program of Biotechnology, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo 11835, Egypt.
- Biology Department, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo 11835, Egypt.
| | - Mohamed N Malash
- Biology Department, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo 11835, Egypt.
- Microbiology and Immunology Department, Faculty of Pharmacy, Ahram Canadian University, Giza 12581, Egypt.
| | - Rania Siam
- Biology Department, School of Sciences and Engineering, American University in Cairo, New Cairo, Cairo 11835, Egypt.
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Zhang QY, Gui JF. Diversity, evolutionary contribution and ecological roles of aquatic viruses. Sci China Life Sci 2018; 61:1486-1502. [DOI: 10.1007/s11427-018-9414-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 09/26/2018] [Indexed: 01/21/2023]
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Affiliation(s)
- Douglas H Bartlett
- Center for Marine Biotechnology and Biomedicine, Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093-0202, USA
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Elbehery AHA, Leak DJ, Siam R. Novel thermostable antibiotic resistance enzymes from the Atlantis II Deep Red Sea brine pool. Microb Biotechnol 2016; 10:189-202. [PMID: 28004885 PMCID: PMC5270753 DOI: 10.1111/1751-7915.12468] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/29/2016] [Accepted: 11/03/2016] [Indexed: 11/29/2022] Open
Abstract
The advent of metagenomics has greatly facilitated the discovery of enzymes with useful biochemical characteristics for industrial and biomedical applications, from environmental niches. In this study, we used sequence-based metagenomics to identify two antibiotic resistance enzymes from the secluded, lower convective layer of Atlantis II Deep Red Sea brine pool (68°C, ~2200 m depth and 250‰ salinity). We assembled > 4 000 000 metagenomic reads, producing 43 555 contigs. Open reading frames (ORFs) called from these contigs were aligned to polypeptides from the Comprehensive Antibiotic Resistance Database using BLASTX. Two ORFs were selected for further analysis. The ORFs putatively coded for 3'-aminoglycoside phosphotransferase [APH(3')] and a class A beta-lactamase (ABL). Both genes were cloned, expressed and characterized for activity and thermal stability. Both enzymes were active in vitro, while only APH(3') was active in vivo. Interestingly, APH(3') proved to be thermostable (Tm = 61.7°C and ~40% residual activity after 30 min of incubation at 65°C). On the other hand, ABL was not as thermostable, with a Tm = 43.3°C. In conclusion, we have discovered two novel AR enzymes with potential application as thermophilic selection markers.
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Affiliation(s)
- Ali H A Elbehery
- Graduate Program of Biotechnology, The American University in Cairo, Cairo, Egypt.,Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - David J Leak
- Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Rania Siam
- Graduate Program of Biotechnology, The American University in Cairo, Cairo, Egypt.,Biology Department and YJ-Science and Technology Research Center, The American University in Cairo, Cairo, Egypt
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9
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Abstract
Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple-extreme conditions, including high temperature, salinity and concentration of heavy metals, are the Red Sea brine pools. We assessed the abundance and distribution of different mobile genetic elements in four Red Sea brine pools including the world's largest known multiple-extreme deep-sea environment, the Red Sea Atlantis II Deep. We report a gradient in the abundance of mobile genetic elements, dramatically increasing in the harshest environment of the pool. Additionally, we identified a strong association between the abundance of insertion sequences and extreme conditions, being highest in the harshest and deepest layer of the Red Sea Atlantis II Deep. Our comparative analyses of mobile genetic elements in secluded, extreme and relatively non-extreme environments, suggest that insertion sequences predominantly contribute to polyextremophiles genome plasticity.
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Affiliation(s)
- Ali H A Elbehery
- Graduate Program of Biotechnology, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Cairo, Egypt
| | - Ramy K Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Rania Siam
- Graduate Program of Biotechnology, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Cairo, Egypt.
- Department of Biology, School of Sciences and Engineering, The American University in Cairo, SSE (Parcel 7), Second Floor, Office: Room 2194, AUC Avenue, New Cairo, 11835, Cairo, Egypt.
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