• Applied Biological Chemistry
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• v.38 no.5
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• pp.387-392
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• 1995

To study the regulatory expression mechanism of soybean glycinin gone, Gy2, the 5' upstream region of the gene was searched for the presence of putative regulatory elements by nucleotide sequencing. It revealed various kinds of regulatory sequence elements commonly found in plant storage protein genes. There were canonical promoter sequences, TATA box (TATAAT) and AGGA box (GAAT) which are common in the 5' upstream region of the plant genes. The embryo factor binding sequence, RY repeat, CACA sequences, ${\alpha}$-conglycinin enhancer-like sequences were also found. To delineate the function of these sequences, 5' upstream deletion mutants of Gy2 were prepared and fused to the ${\alpha}$-glucuronidase (GUS) gene. Each chimeric construct was transferred into soybean protoplasts for transient assay, which led to the identification of the sequences between -281 and -223, -170 and -122, of Gy2 promoter as negative regulatory elements, and the sequences between -223 and -170, -122 and -16 as positive regulatory elements. These results are consistent in transformed tobacco plants as well. The serially deleted promoter fragments fused to the GUS were transformed into Nicotiana tabacum by Agrobacterium tumefaciens using the binary vector system. GUS activity of Gy2 promoter deletion constructs was detected only in seeds but not in leaves with different levels of expression as in transient assay. These results suggest that the glycinin Gy2 promoter drives a tissue-specific expression in transgenic tobacco plants.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.267-273
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• 2003

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.179-186
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• 1998

Dextransucrase hyper-producing Leuconostoc mesenteroides B-512FMCM and dextransucrase constitutive mutants B-742CB and B-1355C catalyzed the transfer of glucose from sucrose to other carbohydrates which were present or were added to the reaction digests. When the acceptor was a maltose, gentiobiose, lactose or raffinose, there was produced a series of oligosaccharide acceptor products or single product based on the kinds of enzymes and reaction conditions. To obtain the quantitative information about the yield and the distribution of acceptor products and dextran two experimental parameters were studied: a) the ratio of acceptor to sucrose and b) the amount of enzyme at constant carbohydrate concentration (100 mM). As the amount of enzyme increased, the synthesis of acceptor products (of maltose or gentiobiose) increased, and the formation of dextran decreased. As the ratio of acceptor to sucrose increased, the amount of dextran and the number of acceptor-products decreased and the amount of acceptor-products increased. When maltose or gentiobiose was an acceptor, the glucose from sucrose was transferred to the C-6 hydroxyl group of the nonreducing-end glucose residue of accepters to give a homologous series of isomaltosyl dextrins. In case of lactose or raffinose, there was produced only one acceptor product from B-512FMCM dextransucrase reaction. In the lactose acceptor reaction, the glucose from sucrose was transferred to the C-2 hydroxyl of the reducing end glucose residue of lactose. To get a series of oligosaccharides from lactose or raffinose acceptor reaction we used B-742CB dextransucrase or B-1355C alternansucrase with 500 mM sucrose in reaction digest.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.893-902
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• 2011

Endophytic fungi are little known for their role in gibberellins (GAs) synthesis and abiotic stress resistance in crop plants. We isolated 10 endophytes from the roots of field-grown soybean and screened their culture filtrates (CF) on the GAs biosynthesis mutant rice line - Waito-C. CF bioassay showed that endophyte GMH-1B significantly promoted the growth of Waito-C compared with controls. GMH-1B was identified as Penicillium minioluteum LHL09 on the basis of ITS regions rDNA sequence homology and phylogenetic analyses. GC/MS-SIM analysis of CF of P. minioluteum revealed the presence of bioactive $GA_4$ and $GA_7$. In endophyte-soybean plant interaction, P. minioluteum association significantly promoted growth characteristics (shoot length, shoot fresh and dry biomasses, chlorophyll content, and leaf area) and nitrogen assimilation, with and without sodium chloride (NaCl)-induced salinity (70 and 140 mM) stress, as compared with control. Field-emission scanning electron microcopy showed active colonization of endophyte with host plants before and after stress treatments. In response to salinity stress, low endogenous abscisic acid and high salicylic acid accumulation in endophyte-associated plants elucidated the stress mitigation by P. minioluteum. The endophytic fungal symbiosis of P. minioluteum also increased the daidzein and genistein contents in the soybean as compared with control plants, under salt stress. Thus, P. minioluteum ameliorated the adverse effects of abiotic salinity stress and rescued soybean plant growth by influencing biosynthesis of the plant's hormones and flavonoids.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1735-1743
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• 2010

The full-length genes gyrB (2,415 bp), parC (2,277 bp), and parE (1,896 bp) in Edwardsiella tarda were cloned by PCR with degenerate primers based on the sequence of the respective quinolone resistance-determining region (QRDR), followed by elongation of 5' and 3' ends using cassette ligation-mediated PCR (CLMP). Analysis of the cloned genes revealed open reading frames (ORFs) encoding proteins of 804 (GyrB), 758 (ParC), and 631 (ParE) amino acids with conserved gyrase/topoisomerase features and motifs important for enzymatic function. The ORFs were preceded by putative promoters, ribosome binding sites, and inverted repeats with the potential to form cruciform structures for binding of DNA-binding proteins. When comparing the deduced amino acid sequences of E. tarda GyrB, ParC, and ParE with those of the corresponding proteins in other bacteria, they were found to be most closely related to Escherichia coli GyrB (87.6% identity), Klebsiella pneumoniae ParC (78.8% identity), and Salmonella Typhimurium ParE (89.5% identity), respectively. The two topoisomerase genes, parC and parE, were found to be contiguous on the E. tarda chromosome. All 18 quinolone-resistant isolates obtained from Korea thus far did not contain subunit alternations apart from a substitution in GyrA (Ser83$\rightarrow$Arg). However, an alteration in the QRDR of ParC (Ser84$\rightarrow$Ile) following an amino acid substitution in GyrA (Asp87$\rightarrow$Gly) was detected in E. tarda mutants selected in vitro at $8{\mu}g/ml$ ciprofloxacin (CIP). A mutant with a GyrB (Ser464$\rightarrow$Leu) and GyrA (Asp87$\rightarrow$Gly) substitution did not show a significant increase in the minimum inhibitory concentration (MIC) of CIP. None of the in vitro mutants exhibited mutations in parE. Thus, gyrA and parC should be considered to be the primary and secondary targets, respectively, of quinolones in E. tarda.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.106-112
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• 2014

Very few plant growth-promoting rhizobacteria (PGPR) are known to produce gibberellins (GAs). The current study aimed to isolate a phytohormone-producing PGP rhizobacterium from soil and assess its potential to enhance plant growth. The newly isolated bacterium was identified as Leifsonia soli sp. SE134 on the basis of partial 16S ribosomal RNA gene sequence. Application of L. soli culture filtrate significantly increased the biomass, hypocotyl, and root lengths of cucumber seeds as compared with non-inoculated sole medium and distilled water treated controls. Furthermore, the PGPR culture was applied to the GA-deficient mutant rice cultivar Waito-C. Treatment with L. soli SE134 significantly increased the growth of Waito-C rice seedlings as compared with controls. Upon chromatographic analysis of L. soli culture, we isolated, detected and quantified different GAs; namely, $GA_1$ ($0.61{\pm}0.15$), $GA_4$ ($1.58{\pm}0.26$), $GA_7$ ($0.54{\pm}0.18$), $GA_8$ ($0.98{\pm}0.15$), $GA_9$ ($0.45{\pm}0.17$), $GA_{12}$ ($0.64{\pm}0.21$), $GA_{19}$ ($0.18{\pm}0.09$), $GA_{20}$ ($0.78{\pm}0.15$), $GA_{24}$ ($0.38{\pm}0.09$), $GA_{34}$ ($0.35{\pm}0.10$), and $GA_{53}$ ($0.17{\pm}0.05$). Plant growth promotion in cucumber, tomato, and young radish plants further evidenced the potential of this strain as a PGP bacterium. The results suggest that GA secretion by L. soli SE134 might prove advantageous for its ameliorative role in crop growth. These findings can be extended for improving the productivity of different crops under diverse environmental conditions.

• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.85-91
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• 2006

Flavanone 3$\beta$-hydroxylase (FHT) is an enzyme acting in the central part of the flavonoid biosynthesis pathway. FHT catalyses the hydroxylation of flavanone to dihydroflavonols in the anthocyanin pathway. In this paper we describe the cloning and expression of the genes encoding the flavonoid-biosynthetic enzyme FHT in Gypsophila paniculata L. A heterologous cDHA probe from Dianthus cavophyllus was used to isolate FHT-encoding cDHA clones from Gypsophila paniculata L.. Inspection of the 1471 bp long sequence revealed an open reading frame 1047 bp, including a 190 bp 5' leader region and 288 bp 3' untranslated region. Comparison of the coding region of this FHT cDHA sequence including the sequences of Arabidopsis thaliana, Citrus sinensis, Dianthus caryophyllus, Ipomoea batatas, Matthiola incana, Nierembergia sp, Petunia hybrida, Solanum tuberosum, Vitis vinifera reveals a identity higher than 69% at the nucleotide level. The function of this nucleotide sequences were verified by comparison with amino acid sequences of the amino-terminus and tryptic peptides from purified plant enzyme, by northern blotting with mRHA from wild type and mutant plants, by in vitro expression yielding and enzymatically active hydroxylase, as indicated by the small dihydrokaempferol peak. Genomic southern blot analysis showed the presence of only one gene for FHT in Gypsophila paniculata.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.394-399
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• 2000

Odontoma is defined as a benign odontogenic tumor containing enmel, dentin as well as cementum. It has come to mean a growth in which both the epithelial and the mesenchymal cells exhibit complete differentiation. Most authorities accept the view today that the odontoma represents a hamartomatous malformation rather than a true neoplasm. The etiology of odontomas is uncertain but hypothesized to involve local trauma, infection, inheritance or mutant gene. The odontomas often cause various disturbances in the eruption and position of the teeth. The steps in removal of an odontoma in close relation to an adjacent impacted normal tooth should comprise 1) removal of odontoma and 2) exposure of the impacted tooth. Orthodontic therapy may be applied. Before treatment, the necessary space for the impacted tooth should be evaluated. If there is lack of space in the dental arch, orthodontic treatment should be carried out before operation.

• KSBB Journal
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• v.24 no.2
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• pp.182-188
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• 2009

Lactobacillus spp., primary members of probiotics, have significant benefits for health and well-being of human. In this study Lactobacillus strains representing six species (L. paracasei KLB58, L. fermentum MS79 and KLB282, L. plantarum KLB213, L. gasseri KLB238, and L. reuteri KLB270) isolated from Korean adults were electrotransformed with plasmid pNCKH104. To determine optimal electrotransformation conditions, various conditions including cell wall weakening agent, electroporation buffer, electric field strength and time constant were tested for each strain. Overall, high transformation efficiency of approximately 2.5 ${\times}$ $10^3$ ${\sim}$ 5.5 ${\times}$ $10^4$ CFU/${\mu}g$ DNA was obtained where conditions of 0.5 M sucrose electroporation buffer, 1.8 kV pulse voltage and 5 ms time constant were applied. The common conditions developed in this study will make transformation of various Lactobacillus spp. easier than previous procedures.

• Korean Journal of Ichthyology
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• v.29 no.2
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• pp.139-145
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• 2017

The spontaneous color mutant, albino individuals of genus Misgurnus, are rarely discovered in Korea and there are difficult to identify morphological species due to lack melanin pigmentation. In this study, we developed a genetic identification method for the species of albino Misgurnus individuals based on phylogenetic analysis by using recombination activating gene 1 (rag1) and cytochrome b (cytb) region of mitochondrial DNA. As a result of molecular phylogenetic analysis, three clades were identified as Misgurnus mizolepis, M. anguillicaudatus and M. mohoity. The homology of the cytb sequences of M. mohoity was best match to that of M. mohoity sequences in GenBank database. As a result of species identification of 25 albino Misgurnus individuals based on the phylogenetic tree, the red-eye type was identified as 16 M. anguillicaudatus and one M. mizolepis. The remaining three individuals were identified as one M. mizolepis ♀${\times}$M. anguillicaudatus ♂, and two M. mohoity ♀${\times}$M. anguillicaudatus ♂, respectively. In addition, the five black-eye type individuals were identified as one M. anguillicaudatus, three M. mizolepis and one M. mohoity. Therefore, this genetic identification method will be an useful techniques for species or hybrid identification in genus Misgurnus.