• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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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.

• Rapid Communication in Photoscience
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• v.3 no.1
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• pp.1-15
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• 2014

We summarize recent studies on photoinduced electron- and energy-transfer processes of various supramolecules including imide group(s) as a component. Recently, imides have been employed in various functional molecular systems, because of their excellent photophysical and electron accepting properties. Our research group also employed imides in various supramolecular systems such as donor-acceptor dyads, quantum dots, DNA, and so on. First, we summarize fundamental properties of imides such as photophysical and electrochemical properties. Then, photoinduced processes of imides in the supramolecular systems are described to show their applicability in the various fields.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.248-252
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• 2005

The virions of causative virus for white spot syndrome in cultured Fresh shrimp, Penaeus chinensis were rod-shaped, double envelope. An average size of the virion was 70 nm in diameter and $250\~300$ nm in length. Histopathological test of affected stomach, heart, and lymphoid organ revealed nuclear hypertrophy. Infectivity trials carried out by injection and feeding with purified virus revealed high cumulative mortality to healthy shrimp. The twenty one different protein species were detected in the analysis of virion. The length of total DNA from the purified virus particles were detected as a single band, double-stranded DNA molecule of approximately 114 kb.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.474-484
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• 1992

The stock identification of small yellow croaker. Pseudosciaena Polyactis from Mokpo area was carried out using molecular biological methods such as mt-DNA restriction fragment length polymorphism(RFLP) and the N-terminal fragment polymorphism of muscle actin obtained after protease digestion. The entire mt-DNA genomic size from the small yellow croaker at Mokpo area was estimated to be about $16\pm0.2$ Kb. Furthermore, fourteen restriction endonucleases revealed a total of 37 restriction sites to the mt-DNA molecule, however, eight of the fourteen enzymes showed a significant restriction site variation. Six of the enzymes examined produced a single restriction profile for all individuals surveyed, indicating that they don't react on the same mt-DNA obtained from small yellow croaker. The Staphylococcus aureus $V_8$ protease is able to cleave the muscle actin of small yellow croaker and to yield a N-terminal peptide of 26 and 16 KDa, respectively.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.117-121
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• 1998

Bacteriophage SC 921 of Lactobacillus plantarum, isolated from kimchi, showed high lytic effects at 0.2 M.O.I. level. The phage particle contained 4 major proteins (48, 34, 32, 29 kDa). Intact DNA of phage SC 921 is a double stranded linear molecule, and the genomic size is approximately 66.5 kilobase pairs (kbp). Restriction analysis of the genome showed that Sma I gave single site cut and Xba I gave 2 site cuts, while Cla I, Kpn I, and EcoR I formed 4, 5, and 6 cuts, respectively. Hind III digested phage DNA to many fragments. A restriction map of genomic DNA was constructed using the restriction endonuclease Kpn I, Sma I, and Xba I. Bacteriophage SC 921 was compared with B2 phage which had been reported to infect Lactobacillus plantarum ATCC 8014(KCCM l1322). Bacteriophage SC 921 differs from B2 phage at least in thr size of its genome and phage particle proteins.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.810-814
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• 2003

For the phylogenetic analysis of procaryotes, 16S rRNA gene has been used. In spite of it's common use, so high conservative of 16S rRNA gene limited resolving power, hence other molecule was applied in this study and the result was compared with that of 16S rRNA. COG (Clusters of Orthologous of protein) algorithm revealed that three COGs were only detected in 42 procaryotes ; transcription elongation factor (COG0195), bacterial DNA primase (COG0358) and uridylate kinase (COG0528). Uridylate kinase gene was selected owing to the similarity and one single copy number in each genome. Phylogenetic tree of 16S rRNA gene and uridylate kinase showed similarities and differences. Uridylate kinase may help the problem of very high conservative of 16S rRNA gene in rhylogenetic analysis and it would help to access more accurate discrimination and phylogenetic analysis of bacteria.

• IMMUNE NETWORK
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• v.13 no.1
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• pp.16-24
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• 2013

CTLA-4Ig is regarded as an inhibitory agent of the T cell proliferation via blocking the costimulatory signal which is essential for full T cell activation. To improve applicability, we developed the CTLA-4Ig-CTKC in which the c-terminal lysine had been replaced by cysteine through single amino acid change. The single amino acid mutation of c-terminus of CTLA-4Ig was performed by PCR and was checked by in vitro transcription and translation. DNA construct of mutant form was transfected to Chinese hamster ovary (CHO) cells by electroporation. The purified proteins were confirmed by Western blot and B7-1 binding assay for their binding ability. The suppressive capacity of CTLA-4Ig-CTKC was evaluated by the mixed lymphocyte reaction (MLR) and in the allogeneic pancreatic islet transplantation model. CTLA-4Ig-CTKC maintained binding ability to B7-1 molecule and effectively inhibits T cell proliferation in MLR. In the murine allogeneic pancreatic islet transplantation, short-term treatment of CTLA-4Ig-CTKC prolonged the graft survival over 100 days. CTLA-4Ig-CTKC effectively inhibits immune response both in MLR and in allogeneic islet transplantation model, indicating that single amino acid mutation does not affect the inhibitory function of CTLA-4Ig. CTLA-4Ig-CTKC can be used in vehicle-mediated drug delivery system such as liposome conjugation.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.362-369
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• 2017

White root rot disease, caused by the pathogen Rosellinia necatrix, is one of the world's most devastating plant fungal diseases and affects several commercially important species of fruit trees and crops. Recent global outbreaks of R. necatrix and advances in molecular techniques have both increased interest in this pathogen. However, the lack of information regarding the genomic structure and transcriptome of R. necatrix has been a barrier to the progress of functional genomic research and the control of this harmful pathogen. Here, we identified 10,616 novel full-length transcripts from the filamentous hyphal tissue of R. necatrix (KACC 40445 strain) using PacBio single-molecule sequencing technology. After annotation of the unigene sets, we selected 14 cell cycle-related genes, which are likely either positively or negatively involved in hyphal growth by cell cycle control. The expression of the selected genes was further compared between two strains that displayed different growth rates on nutritional media. Furthermore, we predicted pathogen-related effector genes and cell wall-degrading enzymes from the annotated gene sets. These results provide the most comprehensive transcriptomal resources for R. necatrix, and could facilitate functional genomics and further analyses of this important phytopathogen.

• Journal of Life Science
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• v.8 no.2
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• pp.119-125
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• 1998

Column-purified double-stranded RNA binding factor (RBF) protein was tested for its binding affinity for the different forms of nucleic acids structure such as single-stranded(ss) and double-stranded(ds)RNA and ss- and dsDNA. The RBF protein was incubated with each of these nucleic acid structures in separate reactions and its comparative binding affnity was visualized by SDS-polyacrylamide gel electrophoresis. The RBF protein bound to the dsRNA molecule to form a tight RNA:protein complex in agreement with previous studies, but not to the other nucleic acid molecules confirming its distinctive affinity for the dsRNA structure. In phosphorylation assay in vito, the purified RBF protein significantly inhibited the autophosphorylation of the PKR derived from not only human but mouse source in the presence of poly(I):poly(C). It is suggesting that PKR vs. RBF is similarly under a competitive interaction among different eukaryotic organisms during protein synthesis.

• Korean Journal of Microbiology
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• v.55 no.2
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• pp.103-111
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• 2019

DNA methylation is involved in diverse processes in bacteria, including maintenance of genome integrity and regulation of gene expression. CcrM, the DNA methyltransferase conserved in Alphaproteobacterial species, carries out $N^6$-adenine or $N^4$-cytosine methyltransferase activities using S-adenosyl methionine as a co-substrate. Celeribacter marinus IMCC12053 from the Alphaproteobacterial group was isolated from a marine environment. Single molecule real-time sequencing method (SMRT) was used to detect the methylation patterns of C. marinus IMCC12053. Gibbs motif sampler program was used to observe the conversion of adenosine of 5'-GANTC-3' to $N^6$-methyladenosine and conversion of $N^4$-cytosine of 5'-GpC-3' to $N^4$-methylcytosine. Exocyclic DNA methyltransferase from the genome of strain IMCC12053 was chosen using phylogenetic analysis and $N^4$-cytosine methyltransferase was cloned. IPTG inducer was used to confirm the methylation activity of DNA methylase, and cloned into a pQE30 vector using dam-/dcm- E. coli as the expression host. The genomic DNA and the plasmid carrying methylase-encoding sequences were extracted and cleaved with restriction enzymes that were sensitive to methylation, to confirm the methylation activity. These methylases protected the restriction enzyme site once IPTG-induced methylases methylated the chromosome and plasmid, harboring the DNA methylase. In this study, cloned exocyclic DNA methylases were investigated for potential use as a novel type of GpC methylase for molecular biology and epigenetics.