• Title/Summary/Keyword: DNA interaction

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Automatic acquisition of local fuzzy reasoning rules through DNA coding method (DNA 코딩 방법을 이용한 국소 퍼지 추론규칙의 자동획득)

  • Park, Jong-Gyu;Yun, Sung-Yong;Oh, Sung-Kwon;Ahn, Tae-Chon
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.543-545
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    • 1999
  • In this paper, the composition method of global and local fuzzy reasoning concepts is researched for reducing the number of rules, not losing the performance for fuzzy controller. A new method is proposed in details that controls the interaction between global reasoning and local reasoning. In order to automatically acquire and optimize the method, the DNA coding algorithm is introduced to the local fuzzy reasoning of the proposed composition fuzzy reasoning method. The method is applied to the real liquid level control system for the purpose of evaluating the Performance. The simulation results show that the proposed technique can produce the fuzzy rules with higher accuracy and feasibility than the conventional methods.

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The regulation of stress induced genes by yeast transcription factor GCN4

  • Seong Kimoon;Lee Jae Yung;Kim Joon
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2002.10a
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    • pp.135-139
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    • 2002
  • Yeast cells respond to condition of amino acid starvation by synthesizing GCN4, a typical eukaryotic transcriptional activator, which regulates the expression of many amino acids biosynthetic genes. By introducing point mutations in the DNA binding domain of GCN4, mutants with normal DNA binding activity but defective in transcriptional activity were isolated to identify unknown proteins that could suppress the mutant phenotype under an amino acid depletion condition. As a result, SSB(Stress-Seventy B) subfamily proteins were identified as suppressors of mutant GCN4. SSB proteins were known as a member of yeast hsp70 family that probably aids passage of nascent chain through ribosomes. Among them, the mechanism of suppression by SSB2 on the defective GCN4 mutant strains is under investigation. Gcn4p directly interacts with Ssb2p through the basic DNA binding domain of GCN4. It suggests the possibility that physical interaction might induce the transcriptional activation of Gcn4p.

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Multiple Functions of the Amino-terminal Domain of Bacteriophage Lambda Integrase: A New Member of Three-stranded $\beta-sheet$ DNA-binding Proteins

  • Cho Eun Hee
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2002.10a
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    • pp.159-161
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    • 2002
  • Bacteriophage lambda integrase carries out the site-specific recombination of lambda. Integrase contains two DNA binding domains with distinct sequence specificity, namely arm-type binding and core-type binding domains. The amino-terminal arm-binding domain is structurally related to the three-stranded $\beta-sheet$ family of DNA-binding domains. Integrase binding to the high affinity arm-type site by the amino-terminal domain facilitates Int binding to the low affinity core-type site, where the cleavage and strand exchange occurs. The amino-terminal domain of Int also modulates the core-binding and catalysis through intramolecular domain-domain interaction and/or intermolecular interactions between Int monomers. In addition, the amino-terminal domain interacts cooperatively with excisionase during excision. This indicates that amino-terminal domain of Int plays an important role in formation of proper higher-order nucleoprotein structure required for lambda site-specific recombination.

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Localization of Sop Proteins and Interaction of Plasmid DNA with the Cell Membrane of Host Bacteria in Partitioning

  • Kim, Sung-Uk;Nagai, Kazuo;Tamura, Gakuzo;Yu, Ju-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.3 no.4
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    • pp.261-265
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    • 1993
  • A sopA protein (41K) encoded by plasmid pXX288 was observed in the cytoplasm, whereas a sopB protein (37K) encoded by plasmid pXX157 was observed in the membrane fraction. Most of the sopB protein was solubilized from the crude membrane by treatment with Sarkosyl, which suggested that the protein may be located in the inner membrane. The sopA protein was precipitated at the concentration of 30 to 60% ammonium sulfate. The sedimentation profile of the crude membrane fraction showed a little difference according to culture media used, and the sopB protein existed in all fractions of inner membrane. The DNA of plasmids, pXX157, pXX300, and pXX167 co-sedimented with inner membrane fraction.

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Interaction of Cu(II)-meso-tetrakis(n-N-methylpyridiniumyl)porphyrin (n = 2,3,4) with Native and Synthetic Polynucleotides Probed by Polarized Spectroscopy

  • Lee, Mi-Jin;Lee, Gil-Jun;Lee, Dong-Jin;Kim, Seog-K.;Kim, Jong-Moon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1728-1734
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    • 2005
  • The interactions of Cu(II)-meso-Tetrakis(n-N-methylpyridiniumyl)porphyrin (n = 2,3,4), respectively referred to as o-, m- and p-CuTMPyP, and DNA, poly$[d(A-T)_2]$ and poly$[d(G-C)_2]$ were investigated by circular and linear dichroism (CD and LD). In the o-CuTMPyP case, in which the rotation of the pyridinium ring is prevented, the shape of the CD spectrum when associated to DNA and poly$[d(A-T)_2]$ resembles and is characterized by a positive band at a low drug to DNA concentration ratio (R ratio) and is bisignate at a high R ratio. The former CD spectrum shape has been attributed to porphyrin that is bound monomerically outside of DNA while the latter can be attributed to those that are stacked. When o-CuTMPyP is bound to poly$[d(G-C)_2]$, the excitonic CD appeared at a relatively high R ratio. In contrast, a characteristic negative CD band in the Soret region was apparent for both m- and p-CuTMPyP when bound to DNA and poly$[d(G-C)_2]$ at the low R ratios, indicating that the porphyrin molecule intercalates. However, the DNA is bent near the intercalation site and the plane of the porphyrin molecule tilts relative to the DNA helix axis, as judged by the magnitude of the reduced LD. Various stacking patterns were identified by the shape of the CD spectrum for m- and p-CuTMPyP when bound to poly$[d(A-T)_2]$. Three species for the former complex and two for the latter complex were found which may reflect the extent of the stacking.

Effect of Interaction between Protocatechualdehyde Produced from Streptomyces lincolnensis M-20 and Copper Ions on Antioxidant and Pro-oxidant Activities (Streptomyces lincolnensis M-20 균주에서 생산된 Protocatechualdehyde와 구리 이온의 상호 작용이 항 산화 및 산화 촉진 활성에 미치는 영향)

  • Kim, Kyoung-Ja;Lee, Jae-Hun;Yang, Yong-Joon
    • Korean Journal of Microbiology
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    • v.50 no.1
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    • pp.22-26
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    • 2014
  • Protocatechualdehyde (PA) is phenolic compound having antioxidative and antitumor activities. PA was purified from supernatant of Streptomyces lincolnensis M-20. In the presence of copper ion, PA acted as pro-oxidant. The antioxidant activity was assessed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, and the pro-oxidant effect of PA on DNA damage as pBR322 plasmid DNA-cleaving agents in the presence of Cu(II) ions was investigated. The involvement of reactive oxygen species (ROS) in the DNA damage was confirmed by the inhibition of the DNA breakage by using glutathione (GSH), specific scavenger of ROS. When the increase in ROS reaches a certain level (the toxic threshold), it may trigger cell death. The formation of the PA/Cu(II) chelate complex was confirmed by reaction with ethylenediamine-tetraacetic acid (EDTA), a well-known chelating agent for metal ions, by using UV/Vis spectroscopic analysis.

Effects of Hin Recombinase Dimer Interface Mutants on DNA Binding and Recombination

  • Lee, Hee-Jung;Lee, Sun-Young;Lee, Hee-Jin;Lim, Heon-Man
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2001.06a
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    • pp.27-31
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    • 2001
  • Previous biochemical assays and a structural model indicated that the dimer interface of the Hin recombinase is composed of the two a-helices. To elucidate the structure and function of the helix, amino acids in the N-terminal end of the helix, where the two helices contact most, were randomized, and inversion-incompetent mutants were selected. To investigate why the mutants lost their inversion activities, the DNA binding, hix-pairing, invertasome formation, and DNA cleavage activities were assayed using in vivo and in vitro methodologies. Results indicated that the mutants could be divided into 4 classes based on their DNA binding activity. We proposed that the a-helices might place a DNA binding motif of Hin properly to the minor DNA groove of the recombination site. All the mutants except the non-binders were able to perform hix-pairing and invertasome formation, suggesting that the dimer interface is not involved in the process of hix-pairing or invertasome formation. The inversion-incompetent phenotype of the binders was caused by the inability of mutants to perform the DNA cleavage activity. The less binders exhibited wild-type level of hix-pairing activity because the hix-pairing activity overcomes the DNA binding defect of the less binders. This phenotype of the less binders suggests that the binding domains of Hin could mediate Hin-Hin interaction during hix-pairing..

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Construction of a High-Quality Yeast Two-Hybrid Library and Its Application in Identification of Interacting Proteins with Brn1 in Curvularia lunata

  • Gao, Jin-Xin;Jing, Jing;Yu, Chuan-Jin;Chen, Jie
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.108-114
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    • 2015
  • Curvularia lunata is an important maize foliar fungal pathogen that distributes widely in maize growing area in China, and several key pathogenic factors have been isolated. An yeast two-hybrid (Y2H) library is a very useful platform to further unravel novel pathogenic factors in C. lunata. To construct a high-quality full length-expression cDNA library from the C. lunata for application to pathogenesis-related protein-protein interaction screening, total RNA was extracted. The SMART (Switching Mechanism At 5' end of the RNA Transcript) technique was used for cDNA synthesis. Double-stranded cDNA was ligated into the pGADT7-Rec vector with Herring Testes Carrier DNA using homologous recombination method. The ligation mixture was transformed into competent yeast AH109 cells to construct the primary cDNA library. Eventually, a high qualitative library was successfully established according to an evaluation on quality. The transformation efficiency was about $6.39{\times}10^5$ transformants/$3{\mu}g$ pGADT7-Rec. The titer of the primary cDNA library was $2.5{\times}10^8cfu/mL$. The numbers for the cDNA library was $2.46{\times}10^5$. Randomly picked clones show that the recombination rate was 88.24%. Gel electrophoresis results indicated that the fragments ranged from 0.4 kb to 3.0 kb. Melanin synthesis protein Brn1 (1,3,8-hydroxynaphthalene reductase) was used as a "bait" to test the sufficiency of the Y2H library. As a result, a cDNA clone encoding VelB protein that was known to be involved in the regulation of diverse cellular processes, including control of secondary metabolism containing melanin and toxin production in many filamentous fungi was identified. Further study on the exact role of the VelB gene is underway.

Cloning of hnRNP E1 cDNA via yeast two-hybrid system and a study on protein-protein interaction between hnRNP E1 and hnRNP K (이스트 two-hybrid 시스템을 이용한 hnRNP E1 cDNA의 클로닝과 hnRNP E1-hnRNP K 상호결합에 대한 연구)

  • Choi, Mie-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1795-1799
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    • 2008
  • The heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a component of hnRNP complexes. This protein binds strongly to cytidine-rich RNA/DNA sequences. It is a nucleocytoplasmic shuttling protein. To investigate the functions of hnRNP K, I searched for hnRNP K-interacting proteins in HeLa cDNA library using a yeast two-hybrid screening system. One of the cDNA clones is identical to human hnRNP E1 (poly(rC) binding protein 1) cDNA (GenBank accession number XM_031585). In this study, hnRNP K is shown to specifically interact with hnRNP E1 in yeast two-hybrid system and in vitro biochemical assay.