• Korean Journal of Microbiology
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• v.32 no.3
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• pp.198-201
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• 1994

The nucleotide sequence of the cohesive end site (cos) of Lactobacillus casei phage J1 genome was determined. Comparison between the nucleotide sequences of the circular cos and the left end of the linear J1 DNA showed that the nicking sites of the terminase were as follows: 5'- GGTCGGCC$\downarrow$ -3' 3'- $\uparrow$CCAGCCGG -5' The cohesive single-stranded ends of J1 were found to be 3'-protruding and composed of 8 nucleotides. The mol% G + C of the cohesive ends was 87.5. The cos site shows dyad symmetry from -33 to + 25 bp if the 5' terminal nucleotide of the left end of the linear J1 DNA is numbered +1. No homology was found among the cos sites of phages reported so far.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.17-17
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• 2011

As a method of countermeasure to bed degradation and armoring phenomena of bed material in the downstream area of dam reservoirs, sediment augmentation (replenished sediment) has been carried out in many Japanese rivers. In general, bed of the replenished sediment site is composed of rocks, because the site is located in the downstream area of the dams and sediment supply is very small. Bed deformation process has been researched by many researchers. As a method of countermeasure to bed degradation and armoring phenomena of bed material in the downstream area of dam reservoirs, sediment augmentation (replenished sediment) has been carried out in many Japanese rivers. In general, bed of the replenished sediment site is composed of rocks, because the site is located in the downstream area of the dams and sediment supply is very small. Bed deformation process has been researched by many researchers. However, most of them can treat movable bed only and cannot be applied to the bed deformation process of sediment on rocks. If the friction angle between the sediment and the bed surface is assumed to be the same as the friction angle between the sediment and the sediment, sediment transport rate must be smaller without sediment deposition layer on the rocks. As a result, the reproduced bed geometry is affected very well. In this study, non-equilibrium transport process of non-cohesive sediment on rigid bed is introduced into the horizontal two dimensional bed deformation model and the model is applied to the erosion process of replenished sediment on rock in the Nakagawa, Japan. Here, the Japanese largest scale sediment augmentation has been performed in the Nakagawa. The results show that the amounts of the eroded sediment and the remained sediment reproduced by the developed numerical model are $56300m^3$ and $26800m^3$, respectively. On the other hand, the amounts of the eroded sediment and the remained sediment measured in the field after the floods are $56600m^3$ and $26500m^3$, respectively. The difference between the model and field data is very small. Furthermore, the bed geometry of the replenished sediment after the floods reproduced by the developed model has a good agreement with the measured bed geometry after the floods. These results indicate that the developed model is able to simulate the erosion process of replenished sediment on rocks very well. Furthermore, the erosion speed of the replenished sediment during the decreasing process of the water discharge is faster than that during the increasing process of the water discharge. The replenished sediment is eroded well, when the top of the replenished sediment is covered by the water. In general, water surface level is kept to be high during the decreasing process of the discharge during floods, because water surface level at the downstream end is high. Hence, it is considered that the high water surface level during the decreasing process of the water discharge affects on the fast erosion of the replenished sediment.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.91-95
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• 1994

EagBI is a type II restriction endonuclease from Enterobacter agglomerans strain CBNU45 isolated from soil. EagBI was partially purified by DEAE-cellulose, phosphocellulose P11 and hydroxylapatite column chromatography. EagBI recognizes and cleaves the sequence 5'-CGAT${\downarrow}$CG-3' and generates 2-base 3'-protruding cohesive ends. The optimal reaction conditions of EagBI are 10 mM Tris-HCl (pH 7.8), 6-10 mM $MgCl_2$, at 37 ${\circ}C$. The enzyme is maximally active in the absence of NaCl, able to cleave both $dam^-$ and $dam^+$ DNAs, and sensitive to heat treatment (at 65 ${\circ}C$ for 10 min). Therefore, although EagBI is an isoschizomer of PvuI, it is more useful than PvuI in respect of the NaCl requirement and heat-stability.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.77-90
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• 1996

Nucleocapsid protein (NP)which exists in the particle of hantavirus and surrounds the viral RNA genome is one of the major structural proteins and plays role of antigen to elicit the antibody detected predorminantly right after infection of the virus in the patients of hemorragic fever with renal syndrome (HFRS)or experimental animals. NP is important target antigen in serological diagnostic system of HFRS utilizing whole antigens from the native virus particle, such as IFA, ELISA and Western blotting. Therefore, the preparation of this protein in the level of higher quantity and purity is desirasble for developed dianosis of the disease. The purpose of this study is the cloning of NP gene which exists in the S genome segment of Maaji (MAA) virus and expression of the gene to obtain qualified, genetically engineered NP to be utilized as an immunodiagnostic antigen. First of all, for the purpose of amplifing the MAA-NP gene by PCR, the specific primers were built from the known nucleotide sequence of Hantaan viral NP gene. The viral cDNA of the NP gene was synthesized by using the primers and RNase $H^-$ AMV reverse transcriptase. Thereafter, using this cDNA as a template, the NP gene was amplified specifically by Taq DNA polymrerase. The pT7blue (R)T-overhang vector systems were used for cloning of the amplified NP gene. The expression system was consisted of BL21 (DE3)pLysS and pET16b as a host and a plasmid repectively. Into Ndel site of pET16b, NP gene was ligated with cohesive end for the expression. Insertion of NP gene in the plasmid was confirmed by PCR and mini prep methods. For expression, IPTG was used and the expressed protein was characterized by Western blotting. The MAA-NP was expressed as the form of inclusion body (insoluble fraction)and the protein purified by affinity and metal chealating columns reacted specifically with the sera from patients of HFRS as to be tested by ELISA and Western blotting.