• 제목/요약/키워드: DNA-binding molecules

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Specific Recognition of Unusual DNA Structures by Small Molecules: An Equilibrium Binding Study

  • Suh, Dong-Chul
    • BMB Reports
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    • 제29권1호
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    • pp.1-10
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    • 1996
  • The binding interaction of ethidium to a series of synthetic deoxyoligonucleotides containing a B-Z junction between left-handed Z-DNA and right-handed B-DNA, was studied. The series of deoxyoligonucleotides was designed so as to vary a dinucleotide step immediately adjacent to a B-Z junction region. Ethidium binds to the right-handed DNA forms and hybrid B-Z forms which contain a B-Z junction, in a highly cooperative manner. In a series of deoxyoligonucleotides, the binding affinity of ethidium with DNA forms which were initially hybrid B-Z forms shows over an order of magnitude higher than that with any other DNA forms, which were entirely in B-form DNA The cooperativity of binding isotherms were described by an allosteric binding model and by a neighbor exclusion model. The binding data were statistically compared for two models. The conformation of allosterically converted DNA forms under binding with ethidium is found to be different from that of the initial B-form DNA as examined by CD spectra. The ratio of the binding constant was interestingly correlated to the free energy of base unstacking and the conformational conversion of the dinucleotide. The more the base stacking of the dinucleotide is unstable, or the harder the conversion of B to A conformation, the higher the ratio of the binding constant of ethidium with the allosterically converted DNA forms and with the initial B-Z hybrid forms. DNA sequence around a B-Z junction region affects the binding affinity of ethidium. The results in this study demonstrate that ethidium could preferentially interact with unusual DNA structures.

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Engineering and Application of Zinc Finger Proteins and TALEs for Biomedical Research

  • Kim, Moon-Soo;Kini, Anu Ganesh
    • Molecules and Cells
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    • 제40권8호
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    • pp.533-541
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    • 2017
  • Engineered DNA-binding domains provide a powerful technology for numerous biomedical studies due to their ability to recognize specific DNA sequences. Zinc fingers (ZF) are one of the most common DNA-binding domains and have been extensively studied for a variety of applications, such as gene regulation, genome engineering and diagnostics. Another novel DNA-binding domain known as a transcriptional activator-like effector (TALE) has been more recently discovered, which has a previously undescribed DNA-binding mode. Due to their modular architecture and flexibility, TALEs have been rapidly developed into artificial gene targeting reagents. Here, we describe the methods used to design these DNA-binding proteins and their key applications in biomedical research.

Covalent Binding of DNA onto Glass Support for the Construction of Genosensor

  • 정우성;백세환
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.709-710
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    • 2000
  • 유전자센서 기술은 biomedical analysis를 위해 일반적으로 고체 상에 고정화된 DNA 분자를 이용한다. 이 센서의 검출능력은 주로 capture probe의 서열뿐만 아니라 oligonucleotide의 고체 상에 고정화 방법에 달려있다. 본 연구에서는 glass 표면에 DNA 분자를 고정화시키는 두 가지 다른 방법을 비교하였고 유전자센서의 구성에 대해 검토하였다.

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Recent advances in developing molecular tools for targeted genome engineering of mammalian cells

  • Lim, Kwang-Il
    • BMB Reports
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    • 제48권1호
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    • pp.6-12
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    • 2015
  • Various biological molecules naturally existing in diversified species including fungi, bacteria, and bacteriophage have functionalities for DNA binding and processing. The biological molecules have been recently actively engineered for use in customized genome editing of mammalian cells as the molecule-encoding DNA sequence information and the underlying mechanisms how the molecules work are unveiled. Excitingly, multiple novel methods based on the newly constructed artificial molecular tools have enabled modifications of specific endogenous genetic elements in the genome context at efficiencies that are much higher than that of the conventional homologous recombination based methods. This minireview introduces the most recently spotlighted molecular genome engineering tools with their key features and ongoing modifications for better performance. Such ongoing efforts have mainly focused on the removal of the inherent DNA sequence recognition rigidity from the original molecular platforms, the addition of newly tailored targeting functions into the engineered molecules, and the enhancement of their targeting specificity. Effective targeted genome engineering of mammalian cells will enable not only sophisticated genetic studies in the context of the genome, but also widely-applicable universal therapeutics based on the pinpointing and correction of the disease-causing genetic elements within the genome in the near future.

PLP-1 Binds Nematode Double-stranded Telomeric DNA

  • Im, Seol Hee;Lee, Junho
    • Molecules and Cells
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    • 제20권2호
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    • pp.297-302
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    • 2005
  • The integrity and proper functioning of telomeres require association of telomeric DNA sequences with specific binding proteins. We have characterized PLP-1, a $PUR{\alpha}$ homolog encoded by F45E4.2, which we previously identified as a candidate double stranded telomere binding protein, by affinity chromatography followed by mass spectrometry. PLP-1 bound double-stranded telomeric DNA in vitro as shown by competition assays. Core binding was provided by the third and fourth nucleotides of the TTAGGC telomeric repeat. This is quite different from the binding sequence of CEH-37, another C. elegans telomere binding protein, suggesting that multiple proteins may bind nematode telomeric DNA simultaneously in vivo.

Cyclic Voltammetric Investigation of Interactions between Bisnitroaromatic Compounds and ds.DNA

  • Janjua, Naveed Kausar;Akhter, Zareen;Jabeen, Fariya;Iftikhar, Bushra
    • 대한화학회지
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    • 제58권2호
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    • pp.153-159
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    • 2014
  • Herein, the cyclic voltammetric (CV) investigations of structurally similar bisnitrocompounds (N3, N4, N5, N6, having different-$CH_2$-spacer length) is presented. CV study offered interesting interactional possibilities of bisnitrocompounds with chicken blood ds.DNA at physiological pH 4.7 and human body temperature, 310 K. The results indicated strong interaction by these symmetric molecules with ds.DNA and strength of binding is found to depend on length of $CH_2$ spacer group in their molecular structure. Thermodynamics derived from electrochemical binding parameters also favored the irreversible interactions. Moreover, threading intercalation mode of binding is suggested based on thermodynamic and kinetic binding parameters extracted from CV studies.

Behavior in Solution and Mixing Ratio-Dependent Binding Modes of Carcinogenic Benzo[a]pyrene-7,8-dione to Calf Thymus DNA

  • Jin, Biao;Han, Sung Wook;Lee, Dong Jin
    • Bulletin of the Korean Chemical Society
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    • 제35권10호
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    • pp.3015-3020
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    • 2014
  • The behavior of benzo[a]pyrene-7,8-dione (BPQ) in aqueous solution and its interaction with native DNA was investigated using conventional absorption and linear dichroism (LD) spectroscopy. The appearance of a broad absorption maximum at long wavelengths and its proportional relationship to solvent polarizability suggested that BPQ adopts a aggregated state for all solutions examined. Disappearance of this absorption band at higher temperatures in aqueous solution also supported BPQ aggregation. When associated with DNA absorption spectral properties were essentially the same as that in aqueous solution. However, two isosbestic wavelengths were found in the concentration-dependent absorption spectrum of the BPQ-DNA complex, suggesting the presence of at least two or more DNA-bound BPQ species. Both species produced $LD^r$ spectra whose magnitude in BPQ absorption region is larger or comparable to that in the DNA absorption region, suggesting that the molecular BPQ plane is near perpendicular relative to the local DNA helical axis. Therefore, BPQ molecules are aligned along the DNA stem in both DNA-aggregated BPQ species.

유전자 발현 조절과 DNA 3차원적 구조와의 관계 (Regulation of Gene Expression and 3-Dimensional Structure of DNA)

  • 김병동
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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    • pp.149-155
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    • 1987
  • Growth and development of a higher plant, or any living organism for that matter, could be defined as an orderly expression of the genome in time and space in close interaction with the environment. During differentiation and development of a tissue or organ a group of genes must be selectively turned on or turned off mainly by trans-acting regulators. In this general concept of regulation of regulation of gene expression, a DNA molecule is recognized at a specific nucleotide sequence by DNA-binding factors. Molecular biology of the regulatory factors such as hormones, and their receptors, target DNA sequences and DNA-binding proteins are well advanced. What is not clearly understood is the molecular basis of the interactions between DNA and binding factors, expecially of the usages of the dyad symmetry of the target DNA sequences and the dimeric nature of the DNA-binding proteins. A unique 3-dimensional structure of DNA has been proposed that may play an important role in the orderly expression of the gene. A foldback intercoil (FBI) DNA configuration which was originally found by electron microscopy among mtDNA molecules from pearl millet has some unique features. The FBI configuration of DNA is believed to be formed when a flexible double helix folds back and interwines in the widened major grooves resulting in a four stranded, intercoil DNA whose thickness is the same as that of double stranded DNA. More recently, the FBI structure of DNA has been also induced in vitro by a novel enzyme which was purified from pearl millet mitochondria. It has been proposed that the FBI DNA could be utillized in intramolecular recombination which leads to inversion or deletion, and in intermolecular recombination which can lead to either site-specific recombination, genetic recombination via single strand invasion, or cross strand recombination. The structure and function of DNA in 3-dimensional aspect is emphasized for better understanding orderly expression of genes during growth and development.

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