• 제목/요약/키워드: ssDNA

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Isolation and Characterization of Chlorella Virus from Fresh Water in Korea and Application in Chlorella Transformation System

  • Park, Hye-Jin;Yoon, Hong-Mook;Jung, Heoy-Kyung;Choi, Tae-Jin
    • The Plant Pathology Journal
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    • 제21권1호
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    • pp.13-20
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    • 2005
  • Chlorella viruses are large icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorellalike green algae. The genomic DNA of over 300 kb contains many useful genes and promoters. Over 40 chlorella viruses have been isolated from fresh water in Korea since 1998. The viruses were amplified initially in chlorella strain NC64A, and pure isolates were obtained by repeated plaque isolation. SDS-PAGE analysis revealed similar but distinct protein patterns, both among the group of purified viruses and in comparison with the prototype chlorella virus PBCV-1. Digestions of the 330- to 350-kb genomic DNAs with 10 restriction enzymes revealed different restriction fragment patterns among the isolates. The tRNA-coding regions of 8 chlorella viruses were cloned and sequenced. These viruses contain 14-16 tRNA genes within a 1.2- to 2-kb region, except for the SS-1 isolate, which has a 1039-bp spacer in a cluster of 11 tRNA genes. Promoter regions of several early genes were isolated and their activities were analyzed in transformed chlorella. Some promoters showed stronger activity than commonly used CaMV 35S promoter and chlorella transformation vectors for heterologous protein are beings constructed using these promoters.

Characterization of Plasmids from Bifidobacterium sp.

  • Lee, Ju-Hoon;Park, Myeong-Soo;Lee, Ke-Ho;Ji, Geun-Eog
    • Journal of Microbiology and Biotechnology
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    • 제11권1호
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    • pp.1-6
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    • 2001
  • Ten strains of plasmid-harboring Bifidobacterium sp. were isolated from the feces of adults and children, and named as Bifidobacterium sp. GE1-GE8, ST, and SH5. These plasmids were categorized into three homologous groups (pKJ50-homologous, pKJ36-homologous, and non-homologous groups) according to Southern hybridization patterns using the formerly characterized bifidobacterial plasmids, pKJ50 and pKJ36, as probes. nine strains harboring the plasmids were shown to accumulate single-stranded DNA as a replication intermediate, based on the S1 nuclease treatment and Southern hybridization. These results suggest that the strains replicate by a rolling circle mechanism. Minimal inhibitory concentrations (MIC) of the isolated bifidobacteria against several antibiotics were determined. Two strains, GE2 and GE3, showed relatively high MiC values against tetracycline ($793.6{\mu}g/ml$) and erythromycin ($153.6{\mu}g/ml$), respectively. The tetracycline resistance of GE2 disappeared when the resident plasmid of GE2 was cured by ethidium bromide. These results show that pKJ36-homologous and pKJ50-homologous plasmids are prevalent among various Bifidobacterium strains and some Bifidobacterium plasmids appear to code for antibiotic resistance.

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Improvement of Transformation Efficiencies using Agrobacterium-Mediated Transformation of Korean Rice

  • Cho, Joon-Hyeong;Lee, Jang-Yong;Kim, Yong-Wook;Lee, Myoung-Hoon;Park, Seong-Ho
    • 한국작물학회지
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    • 제49권1호
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    • pp.61-68
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    • 2004
  • A reproducible transformation system via optimized regeneration media for Korean rice cultivars was established using Agrobacterium tumefeciens LBA4404 (pSBM-PPGN; gusA and bar). Although japonica rice genotypes were easier to produce transgenic plants compared to Tongil type cultivars, transformation efficiencies were not always correlated with regeneration efficiencies of non-transgenic callus on the control medium. Regeneration efficiencies of Donganbyeo, Ilmibyeo, and Manchubyeo were over 50% in non-transgenic control, however, transformation efficiencies were significantly low when only sucrose was added to the media as a carbon source. However, the medium, MSRK5SS-Pr (or MSRK5SM-Pr), that contains $5\textrm{mgL}^{-1}$ kinetin, $0.5\textrm{mgL}^{-1}$ NAA, 2 % sucrose (or maltose), 3% sorbitol, and $500\textrm{mgL}^{-1}$ proline, was the most efficient not only for regeneration of non-transgenic callus but also for regeneration of transgenic callus in the presence of L-phosphinotricin (PPT). Average transformation efficiencies of 16 Korean rice cultivars were significantly enhanced by using the optimized medium from 1.5% to 5.8% in independent callus lines and from 2.9% to 19.4% in tromsgenic plants obained. Approximately 98.9% (876 out of 885) transgenic plants obtained on optimized media showed basta resistance. Stable integration, inheritance and expression of gusA and bar genes were continued by GUS assay and PCR and Southern analysis of the bar gene. With Pst1 digestion of genomic DNA of transgenic plants, one to five copies of T-DNA segment were observed; however, 76% (19 out of 25 transgenic plants) has low copy number of T-DNA. The transformants obtained from one callus line showed the same copy numbers with the same fractionized band patterns.

Purification and Characterization of an Acid Deoxyribonuclease from the Cultured Mycelia of Cordyceps sinensis

  • Ye, Maoqing;Hu, Zheng;Fan, Ying;He, Ling;Xia, Fubao;Zou, Guolin
    • BMB Reports
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    • 제37권4호
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    • pp.466-473
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    • 2004
  • A new acid deoxyribonuclease (DNase) was purified from the cultured mycelia of Cordyceps sinensis, and designated CSDNase. CSDNase was purified by $(NH_4)_2SO_4$ precipitation, Sephacryl S-100 HR gel filtration, weak anion-exchange HPLC, and gel filtration HPLC. The protein was single-chained, with an apparent molecular mass of ca. 34 kDa, as revealed by SDS-PAGE, and an isoelectric point of 7.05, as estimated by isoelectric focusing. CSDNase acted on both double-stranded (ds) and single- stranded (ss) DNA, but preferentially on dsDNA. The optimum pH of CSDNase was pH 5.5 and its optimum temperature 55. The activity of CSDNase was not dependent on divalent cations, but its enzymic activity was inhibited by high concentration of the cation: $MgCl_2$ above 150 mM, $MnCl_2$ above 200 mM, $ZnCl_2$ above 150 mM, $CaCl_2$ above 200 mM, NaCl above 300 mM, and KCl above 300 mM. CSDNase was found to hydrolyze DNA, and to generate 3-phosphate and 5-OH termini. These results indicate that the nucleolytic properties of CSDNase are essentially the same as those of other well-characterized acid DNases, and that CSDNase is a member of the acid DNase family. To our knowledge, this is the first report of an acid DNase in a fungus.

Emerging functions for ANKHD1 in cancer-related signaling pathways and cellular processes

  • de Almeida, Bruna Oliveira;Machado-Neto, Joao Agostinho
    • BMB Reports
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    • 제53권8호
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    • pp.413-418
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    • 2020
  • ANKHD1 (ankyrin repeat and KH domain containing 1) is a large protein characterized by the presence of multiple ankyrin repeats and a K-homology domain. Ankyrin repeat domains consist of widely existing protein motifs in nature, they mediate protein-protein interactions and regulate fundamental biological processes, while the KH domain binds to RNA or ssDNA and is associated with transcriptional and translational regulation. In recent years, studies containing relevant information on ANKHD1 in cancer biology and its clinical relevance, as well as the increasing complexity of signaling networks in which this protein acts, have been reported. Among the signaling pathways of interest in oncology regulated by ANKHD1 are Hippo signaling, JAK/STAT, and STMN1. The scope of the present review is to survey the current knowledge and highlight future perspectives for ANKHD1 in the malignant phenotype of cancer cells, exploring biological, functional, and clinical reports of this protein in cancer.

저혈소판증을 동반한 급성 대뇌경색을 보인 원발성 쇼그렌 증후군 1례 (Acute cerebral infarction associated with thrombocytopenia in primary Sjogren's syndrome : A Case Report)

  • 최판규;강현구
    • 한국산학기술학회논문지
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    • 제18권7호
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    • pp.565-568
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    • 2017
  • 쇼그렌 증후군은 입안 건조와 호중성백혈구 감소증을 주로 보이는 자가면역질환이다. 일반적으로 쇼그렌 증후군은 중추신경계를 잘 침범하지 않는 것으로 알려져 있다. 하지만 드물게, 쇼그렌 증후군에서 미세혈관병성 변성이 생기고, 이로 인해 소혈관에 영향을 미치기도 한다. 34세의 여자 환자가 왼쪽 위사분맹 및 왼쪽 팔다리의 저린 증상이 있어 내원하였다. 뇌자기공명영상에서 오른쪽 후대뇌동맥 영역의 급성 뇌경색 소견이 확인되었다. 혈액학적 검사는 항핵항체 (FANA2+) 및 항DNA항체 (anti-SS-A (RO)) 양성이었다. 그리고 침샘 섬광조영술에서 타액 분비양이 현저히 저하되었다. 따라서 환자는 쇼그렌 증후군으로 진단할 수 있었다. 본 환자의 경우처럼 쇼그렌 증후군에서 대혈관을 침범하는 것은 매우 드문 일이다. 또한 쇼그렌 증후군 환자가 저혈소판증을 보였을 경우, 항혈소판 제재를 쓰는 것이 어려울 수 있다. 이 연구는 대혈관 침범 및 저혈소판증을 보인 쇼그렌 증후군 환자에서 항혈소판 제재 및 하이드록시클로로퀸을 통한 성공적인 치료와, 이와 관련된 임상 양상 및 병태생리를 보고한 사례연구이다.

Characterization of Plasmid pKJ36 from Bifidobacterium longum and Construction of an E. coli-Bifidobacterium Shuttle Vector

  • Park, Nyeong-Soo;Shin, Dong-Woo;Lee, Ke-Ho;Ji, Geun-Eog
    • Journal of Microbiology and Biotechnology
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    • 제10권3호
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    • pp.312-320
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    • 2000
  • Abstract The full sequence of the plasmid pKJ36, which was derived from Bifidobacterium longum KJ, was determined and analyzed to construct shuttle vectors between E. coli and Bifidobacterium. The plasmid pKJ36 was composed of 3,625 base pairs with a 65.1% G+C content. The structural organization of pKJ36 was highly similar to that of pKJ50, and the three major ORFs on pKJ36 showed high amino acid sequence homologies with those of pKJ50. The putative proteins coded by these three ORFs were designated as RepB (32.0 kDa, pI=9.25), MembB (29.0 kDa, pI=12.25), and MobB (39.0 kDa, pI=IO.66), respectively. The amino acid sequence of RepB showed a 57% identity and 70% similarity with that of the RepA protein of pKJ50. Upstream of the repB gene, the so-called iteron sequence was directly repeated four-and-ahalf times and a conserved dnaA box was identified. An amino acid sequence comparison between the MobB and MobA of pKJ50 revealed a 48% identity and 61 % similarity. A conserved oriT sequence with an inverted repeat identical to that of pKJ50 was also found upstream of the mobB gene. A hydropathy analysis of MembB revealed four possible transmembrane regions. The expressions of the repB and membB genes were confirmed by RT-PCR. The in vitro translation reaction of pKJ36 showed protein bands with anticipated sizes with respect to each putative gene product. S 1 endonuclease treatment and Southern hybridization suggested that pKJ36 replicates by a rolling circle mechanism via a single-stranded DNA (ssDNA) intermediate. A shuttle vector between E. coli and Bifidobacterium sp. was constructed using the pKJ36, pBR322, and staphylococcal chloramphenicol acetyl transferase (CAT) gene. The successful transformation of the Bifidobacterium strains was shown by Southern hybridization and PCR. The transformation efficiency differed from strain to strain and, depending on the electroporation conditions, with a range between $1.2{\times}10^1-2.6{\times}10^2{\;}cfu/\mu\textrm{g}$ DNA.X> DNA.

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Bacterial Hash Function Using DNA-Based XOR Logic Reveals Unexpected Behavior of the LuxR Promoter

  • Pearson, Brianna;Lau, Kin H.;Allen, Alicia;Barron, James;Cool, Robert;Davis, Kelly;DeLoache, Will;Feeney, Erin;Gordon, Andrew;Igo, John;Lewis, Aaron;Muscalino, Kristi;Parra, Madeline;Penumetcha, Pallavi;Rinker, Victoria G.;Roland, Karlesha;Zhu, Xiao;Poet, Jeffrey L.;Eckdahl, Todd T.;Heyer, Laurie J.;Campbell, A. Malcolm
    • Interdisciplinary Bio Central
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    • 제3권3호
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    • pp.10.1-10.8
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    • 2011
  • Introduction: Hash functions are computer algorithms that protect information and secure transactions. In response to the NIST's "International Call for Hash Function", we developed a biological hash function using the computing capabilities of bacteria. We designed a DNA-based XOR logic gate that allows bacterial colonies arranged in a series on an agar plate to perform hash function calculations. Results and Discussion: In order to provide each colony with adequate time to process inputs and perform XOR logic, we designed and successfully demonstrated a system for time-delayed bacterial growth. Our system is based on the diffusion of ${\ss}$-lactamase, resulting in destruction of ampicillin. Our DNA-based XOR logic gate design is based on the op-position of two promoters. Our results showed that $P_{lux}$ and $P_{OmpC}$ functioned as expected individually, but $P_{lux}$ did not behave as expected in the XOR construct. Our data showed that, contrary to literature reports, the $P_{lux}$ promoter is bidirectional. In the absence of the 3OC6 inducer, the LuxR activator can bind to the $P_{lux}$ promoter and induce backwards transcription. Conclusion and Prospects: Our system of time delayed bacterial growth allows for the successive processing of a bacterial hash function, and is expected to have utility in other synthetic biology applications. While testing our DNA-based XOR logic gate, we uncovered a novel function of $P_{lux}$. In the absence of autoinducer 3OC6, LuxR binds to $P_{lux}$ and activates backwards transcription. This result advances basic research and has important implications for the widespread use of the $P_{lux}$ promoter.

해수에 순치된 첨연어(Oncorhynchus keta)에서 분리된 정형 에로모나스 살모니시다(Aeromonas salmonicida)에 대한 특성 분석 (Characterization of typical Aeromonas salmonicida isolated from Sea-Chum Salmon (Oncorhynchus keta) )

  • 임종원;고성재;박영준;안도일;홍수희
    • 한국어병학회지
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    • 제36권2호
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    • pp.263-275
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    • 2023
  • 첨연어(Oncorhynchus keta)는 한국에서 회귀하는 연어로 종 보존을 위해 경상북도 울진군에 위치한 수산자원공단에서 해수 순치하며 종묘 생산하였다. 그러나, 사육 중이던 첨연어 치어에서 세균성 질병에 감염된 증상을 보이며 폐사하였다. 따라서, 본 연구에서는 2021년 10월경에 사육환경에 따라 구분된 첨연어로부터 원인체를 규명하고자 세균을 분리하였다. 분리된 세균은 16S rDNA, rpoD (RNA polymerase sigma factor σ70) 및 vapA (A-layer)의 염기서열을 기반으로 유전학적으로 동정하고, 추가로 염분에 따른 성장, 생화학적 특성 분석, 항생제 감수성 및 병원성 인자를 분석하여 균주를 특성화하였다. 그 결과, 분리된 4개의 균주는 모두 Aeromonas salmonicida subsp. salmonicida 아종으로 동정하였다. 또한, 분리된 균주는 염분의 농도가 증가할수록 배지에서 성장이 감소하였다. 생화학적 특성 분석에서 분리된 4개 균주는 용혈성이 확인되지 않았고, 모두 같은 생화학적인 성상을 나타냈다. 항생제 감수성 분석에서는 oxolinic acid, flumequine 그리고 florfenicol에 대한 항생제에서 40~44 mm 억제대를 형성하였다. 병원성 인자의 발현 분석은 mRNA 수준에서 RT-PCR로 확인되었으며, 4개 균주는 모두 A. salmonicida의 병원성에 크게 기여한다고 잘 알려진 outer membrane ring of T3SS (ascV), inner membrane ring of T3SS (ascC), vapA, enterotoxin (act) 및 lipase (lip) 유전자가 발현되었다. 이 연구에서 분리된 A. salmonicida subsp. salmonicida의 특성 분석은 해수에 순치된 첨연어에서 발병하는 절창병을 예방하기 위한 기초자료로 활용될 수 있을 것이다.

DNA Polymorphisms in SREBF1 and FASN Genes Affect Fatty Acid Composition in Korean Cattle (Hanwoo)

  • Bhuiyan, M.S.A.;Yu, S.L.;Jeon, J.T.;Yoon, D.;Cho, Y.M.;Park, E.W.;Kim, N.K.;Kim, K.S.;Lee, J.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권6호
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    • pp.765-773
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    • 2009
  • Sterol regulatory element binding factor 1 (SREBF1) and fatty acid synthase (FASN) genes play an important role in the biosynthesis of fatty acids and cholesterol, and in lipid metabolism. This study used polymorphisms in the intron 5 of bovine SREBF1 and in the thioesterase (TE) domain of FASN genes to evaluate their associations with beef fatty acid composition. A previously identified 84-bp indel (L: insertion/long type and S: deletion/short type) of the SREBF1 gene in Korean cattle had significant associations with the concentration of stearic (C18:0), linoleic (C18:2) and polyunsaturated fatty acids (PUFA). The stearic acid concentration was 6.30% lower in the SS than the LL genotype (p<0.05), but the linoleic and PUFA contents were 11.06% and 12.20% higher in SS compared to LL (p<0.05). Based on the sequence analysis, five single nucleotide polymorphisms (SNPs) g.17924G>A, g.18043C>T, g.18440G>A, g.18529G>A and g.18663C>T in the TE domain of the FASN gene were identified among the different cattle breeds studied. Among these, only g.17924 G>A and g.18663C>T SNPs were segregating in the Hanwoo population. The g.17924G>A SNP is a non-synonymous mutation (thr2264ala) and was significantly associated with the contents of palmitic (C16:0) and oleic acid (C18:1). The oleic acid concentration was 3.18% and 2.79% higher in Hanwoo with the GG genotype than the AA and AG genotypes, respectively (p<0.05), whereas the GG genotype had 3.8% and 4.01% lower palmitic acid than in those cattle with genotype AA and AG, respectively (p<0.05). Tissue expression data showed that SREBFI and FASN genes were expressed in a variety of tissues though they were expressed preferentially in different muscle tissues. In conclusion, the 84-bp indel of SREBF1 and g.17924G>A SNP of the FASN gene can be used as DNA markers to select Hanwoo breeding stock for fatty acid composition.