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Han P, Fan H, Tong Y. Identification of a novel family B DNA polymerase from Enterococcus phage IME199 and its overproduction in Escherichia coli BL21(DE3). Microb Cell Fact 2023; 22:217. [PMID: 37865739 PMCID: PMC10590003 DOI: 10.1186/s12934-023-02228-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/11/2023] [Indexed: 10/23/2023] Open
Abstract
BACKGROUND Identification and characterization of novel, faithful and processive DNA polymerases is a driving force in the development of DNA amplification methods. Purification of proteins from natural phages is often time-consuming, cumbersome and low yielding. Escherichia coli is a host bacterium widely used for the production of recombinant proteins, is the cell factory of choice for in vitro studies of phage protein function. RESULTS We expressed the gene encoding Enterococcus faecium phage IME199 DNA polymerase (IME199 DNAP) in Escherichia coli BL21(DE3), and characterized protein function. IME199 DNAP has 3'-5' exonuclease activity, but does not have 5'-3' exonuclease activity. In addition, IME199 DNAP has dNTP-dependent 5'-3' polymerase activity and can amplify DNA at 15-35 °C and a pH range of 5.5-9.5. The amino acid residues Asp30, Glu32, Asp112 and Asp251 are the 3'-5' exonuclease active sites of IME199 DNAP, while residues Asp596 and Tyr639 are essential for DNA synthesis by IME199 DNAP. More importantly, the IME199 DNAP has strand displacement and processive synthesis capabilities, and can perform rolling circle amplification and multiple displacement amplification with very low error rates (approximately 3.67 × 10-6). CONCLUSIONS A novel family B DNA polymerase was successfully overproduced in Escherichia coli BL21(DE3). Based on the characterized properties, IME199 DNAP is expected to be developed as a high-fidelity polymerase for DNA amplification at room temperature.
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Affiliation(s)
- Pengjun Han
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Huahao Fan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Yigang Tong
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
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Camacho E, González-de la Fuente S, Solana JC, Tabera L, Carrasco-Ramiro F, Aguado B, Requena JM. Leishmania infantum (JPCM5) Transcriptome, Gene Models and Resources for an Active Curation of Gene Annotations. Genes (Basel) 2023; 14:genes14040866. [PMID: 37107624 PMCID: PMC10137940 DOI: 10.3390/genes14040866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/25/2023] [Accepted: 04/01/2023] [Indexed: 04/08/2023] Open
Abstract
Leishmania infantum is one of the causative agents of visceral leishmaniases, the most severe form of leishmaniasis. An improved assembly for the L. infantum genome was published five years ago, yet delineation of its transcriptome remained to be accomplished. In this work, the transcriptome annotation was attained by a combination of both short and long RNA-seq reads. The good agreement between the results derived from both methodologies confirmed that transcript assembly based on Illumina RNA-seq and further delimitation according to the positions of spliced leader (SAS) and poly-A (PAS) addition sites is an adequate strategy to annotate the transcriptomes of Leishmania, a procedure previously used for transcriptome annotation in other Leishmania species and related trypanosomatids. These analyses also confirmed that the Leishmania transcripts boundaries are relatively slippery, showing extensive heterogeneity at the 5′- and 3′-ends. However, the use of RNA-seq reads derived from the PacBio technology (referred to as Iso-Seq) allowed the authors to uncover some complex transcription patterns occurring at particular loci that would be unnoticed by the use of short RNA-seq reads alone. Thus, Iso-Seq analysis provided evidence that transcript processing at particular loci would be more dynamic than expected. Another noticeable finding was the observation of a case of allelic heterozygosity based on the existence of chimeric Iso-Seq reads that might be generated by an event of intrachromosomal recombination. In addition, we are providing the L. infantum gene models, including both UTRs and CDS regions, that would be helpful for undertaking whole-genome expression studies. Moreover, we have built the foundations of a communal database for the active curation of both gene/transcript models and functional annotations for genes and proteins.
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Affiliation(s)
- Esther Camacho
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Instituto Universitario de Biología Molecular (IUBM), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Jose Carlos Solana
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Instituto Universitario de Biología Molecular (IUBM), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Laura Tabera
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Genomic and NGS Facility (GENGS), 28049 Madrid, Spain
| | - Fernando Carrasco-Ramiro
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Genomic and NGS Facility (GENGS), 28049 Madrid, Spain
| | - Begoña Aguado
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Genomic and NGS Facility (GENGS), 28049 Madrid, Spain
| | - Jose M. Requena
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Instituto Universitario de Biología Molecular (IUBM), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
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Guo X, Zhang T, Jin M, Zeng R. Characterization of Bacillus phage Gxv1, a novel lytic Salasvirus phage isolated from deep-sea seamount sediments. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:13-19. [PMID: 37073390 PMCID: PMC10077186 DOI: 10.1007/s42995-020-00074-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/14/2020] [Indexed: 05/03/2023]
Abstract
Seamounts are hotspots for marine life, but to date, no bacteriophages have been reported. Here, a novel Bacillus podophage (named as Bacillus phage Gxv1) was isolated from deep-sea seamount sediments of the western Pacific Ocean (~ 5790 m). Phage Gxv1 has a hexameric head ~ 42-53 nm in diameter and a short tail of ~ 30 nm long, which is a typical feature of the Podoviridae family. One-step curve analysis showed that Gxv1 is a lytic phage that can initiate host lysis within 3.5 h post-infection, and has a relatively large burst size. The 21,781-bp genome contains 34 predicted genes, and the G + C content of phage Gxv1 is 39.69%. Whole-genome comparison of phage Gxv1 with known bacteriophages, using BlastN analysis against the IMG/VR database, revealed that phage Gxv1 is closely related to Bacillus phage phi29 that infects Bacillus subtilis, and their genome-wide similarity is 93.62%. Phylogenetic analysis based on DNA polymerase showed that phage Gxv1 belongs to the Salasvirus genus. Multiple genome alignment showed that phage Gxv1 shares a high level of sequence similarity and common gene order with Bacillus phage phi29. However, some sequences are unique to phage Gxv1, and this region contains genes encoding DNA packing protein, DNA replication protein, and unknown protein. These sequences exhibit low sequence similarity to known bacteriophages, highlighting an unknown origin of these sequences. This study will help improve our understanding of the Salasvirus genus and phage diversity in deep-sea seamounts.
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Affiliation(s)
- Xun Guo
- State Key Laboratory Breeding Base of Marine Genetic Resource, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, 361005 China
| | - Tianyou Zhang
- State Key Laboratory Breeding Base of Marine Genetic Resource, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, 361005 China
| | - Min Jin
- State Key Laboratory Breeding Base of Marine Genetic Resource, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, 361005 China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000 China
| | - Runying Zeng
- State Key Laboratory Breeding Base of Marine Genetic Resource, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, 361005 China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000 China
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Bores C, Woodson M, Morais MC, Pettitt BM. Effects of Model Shape, Volume, and Softness of the Capsid for DNA Packaging of phi29. J Phys Chem B 2020; 124:10337-10344. [PMID: 33151690 PMCID: PMC7903877 DOI: 10.1021/acs.jpcb.0c07478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Double-stranded DNA is under extreme confinement when packed in phage phi29 with osmotic pressures approaching 60 atm and densities near liquid crystalline. The shape of the capsid determined from experiment is elongated. We consider the effects of the capsid shape and volume on the DNA distribution. We propose simple models for the capsid of phage phi29 to capture volume, shape, and wall flexibility, leading to an accurate DNA density profile. The effect of the packaging motor twisting the DNA on the resulting density distribution has been explored. We find packing motor induced twisting leads to a greater numbers of defects formed. The emergence of defects such as bubbles or large roll angles along the DNA shows a sequence dependence, and the resulting flexibility leads to an inhomogeneous distribution of defects occurring more often at TpA steps and AT-rich regions. In conjunction with capsid elongation, this has effects on the global DNA packing structures.
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Affiliation(s)
- Cecilia Bores
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, United States
| | - Michael Woodson
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, United States
| | - Marc C Morais
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, United States
| | - B Montgomery Pettitt
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, United States
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Takahashi H, Yamazaki H, Akanuma S, Kanahara H, Saito T, Chimuro T, Kobayashi T, Ohtani T, Yamamoto K, Sugiyama S, Kobori T. Preparation of Phi29 DNA polymerase free of amplifiable DNA using ethidium monoazide, an ultraviolet-free light-emitting diode lamp and trehalose. PLoS One 2014; 9:e82624. [PMID: 24505243 PMCID: PMC3915000 DOI: 10.1371/journal.pone.0082624] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/25/2013] [Indexed: 11/25/2022] Open
Abstract
We previously reported that multiply-primed rolling circle amplification (MRPCA) using modified random RNA primers can amplify tiny amounts of circular DNA without producing any byproducts. However, contaminating DNA in recombinant Phi29 DNA polymerase adversely affects the outcome of MPRCA, especially for negative controls such as non-template controls. The amplified DNA in negative control casts doubt on the result of DNA amplification. Since Phi29 DNA polymerase has high affinity for both single-strand and double-stranded DNA, some amount of host DNA will always remain in the recombinant polymerase. Here we describe a procedure for preparing Phi29 DNA polymerase which is essentially free of amplifiable DNA. This procedure is realized by a combination of host DNA removal using appropriate salt concentrations, inactivation of amplifiable DNA using ethidium monoazide, and irradiation with visible light from a light-emitting diode lamp. Any remaining DNA, which likely exists as oligonucleotides captured by the Phi29 DNA polymerase, is degraded by the 3'-5' exonuclease activity of the polymerase itself in the presence of trehalose, used as an anti-aggregation reagent. Phi29 DNA polymerase purified by this procedure has little amplifiable DNA, resulting in reproducible amplification of at least ten copies of plasmid DNA without any byproducts and reducing reaction volume. This procedure could aid the amplification of tiny amounts DNA, thereby providing clear evidence of contamination from laboratory environments, tools and reagents.
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Affiliation(s)
- Hirokazu Takahashi
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Hiroyuki Yamazaki
- Isehara Research Laboratory, Technology & Development Division, Kanto Chemical Co., Inc., Isehara, Kanagawa, Japan
| | - Satoshi Akanuma
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Hiroko Kanahara
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Toshiyuki Saito
- Transcriptome Profiling Group, National Institute of Radiological Sciences, Chiba, Chiba, Japan
| | - Tomoyuki Chimuro
- Isehara Research Laboratory, Technology & Development Division, Kanto Chemical Co., Inc., Isehara, Kanagawa, Japan
| | - Takayoshi Kobayashi
- Bio-Chemical Department, Reagent Division, Kanto Chemical Co., Inc. Tokyo, Japan
| | - Toshio Ohtani
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Kimiko Yamamoto
- Insect Genome Laboratory, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
| | - Shigeru Sugiyama
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Toshiro Kobori
- Nanobiotechnology Laboratory, Food Engineering Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
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