• 미생물학회지
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• 제41권2호
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• pp.125-128
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• 2005

S. chungbukensis DJ77로부터 16S rRNA유전자의 염기서열을 분식하였다. 염기서열은 총 1,502 bp로 2000 년에 등록된 부분 서열(1,435 bp)보다 5' 방향과 3' 방향으로 29 bp와 37 bp 길이만큼 각각 확장하였으며, 1 bp가 추가로 삽입되었다. E. coli의 16S rRNA유전자를 모델로 이차구조를 제작하였으며, 네 부위가 특이적임을 발견하였다. Sphnigomonas spp.의 16S rRNA 서열과 S. chungbukensis DJ77의 다중서열검색 결과, Sphingomonas종에서만 나타나는 보존부위와 가변부위를 발견할 수 있었다. 특히, Campylobacter jejuni에서만 나타나는 것으로 알려진 긴 stem loop구조가 서열은 조금 다르지만 구조적 일치를 보이는 유사한 구조를 S. chungbukensis DJ77에서도 발견하였다. 결과적으로, 다중서열검색을 통해 제작한 계통수와 nucleotide signatures분석에 근거하여 S. chugukensis DJ77을 cluster II (Sphingobium)로 분류하였다.

• Parasites, Hosts and Diseases
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• 제45권2호
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• pp.87-94
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• 2007

In this study, we describe Korean isolates of Trichomonas vaginalis infected with double-stranded (ds) RNA virus (TVV). One T. vaginalis isolate infected with TVV IH-2 evidenced weak pathogenicity in the mouse assay coupled with the persistent presence of a dsRNA, thereby indicating a hypovirulence effect of dsRNA in T. vaginalis. Cloning and sequence analysis results revealed that the genomic dsRNA of TVV IH-2 was 4,647 bp in length and evidenced a sequence identity of 80% with the previously-described TVV 1-1 and 1-5, but only a 42% identity with TVV 2-1 and 3 isolates. It harbored 2 overlapping open reading frames of the putative capsid protein and dsRNA-dependent RNA polymerase (RdRp). As previously observed in the TVV isolates 1-1 and 1-5, a conserved ribosomal slip-page heptamer (CCUUUUU) and its surrounding sequence context within the consensus 14-nt overlap implied the gene expression of a capsid protein-RdRp fusion protein, occurring as the result of a potential ribosomal frameshift event. The phylogenetic analysis of RdRp showed that the Korean TVV If-2 isolate formed a compact group with TVV 1-1 and 1-5 isolates, which was divergent from TVV 2-1, 3 and other viral isolates classified as members of the Giardiavirus genus.

• 식물병연구
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• 제23권3호
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• pp.288-293
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• 2017

Chrysanthemum chlorotic mottle viroid (CChMVd) fused to the leader sequence of a reporter gene (mRFP) expressed transiently in agroinfiltrated Nicotiana benthamiana, was used to show that CChMVd can traffic into chloroplasts, thought to be the site of its replication. Fluorescence from mRFP was detected in chloroplasts, but only if the viroid transcription fusions were present, either from the full-length 400-nt CChMVd, or each of two partial fragments (nucleotides 125 to 2 and 231 to 372). The mRFP and its mRNA were detected by western blotting and RT-PCR, respectively, in tissue extracts of plants infiltrated by each fusion construct. Isolated chloroplasts were shown by RT-PCR to contain the RNA sequences of both CChMVd and mRFP, if both were present, but not the mRFP sequence in the absence of the viroid sequences. The results suggest that RNA trafficking was probably due to an RNA structure, and not a particular sequence, as discussed.

• 대한바이러스학회지
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• 제27권1호
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• pp.1-8
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• 1997

Human caliciviruses (HuCVs) cause sporadic cases and outbreaks of acute gastroenteritis (AGE). Three major genogroups of HuCVs have been described including the Norwalk virus (NV)-, the Snow Mountain virus (SMA)-, and the Sapporo-genogroups. This study describes the detection and genetic variation of HuCVs from hospitalized infants with AGE in Korea by RT-PCR and sequencing. The cDNA fragments of 206 to 470bp corresponding to the region of 3 primer pairs (36/35, 35/51 or 3/51) in the polymerase region of NV were generated. Of 185 stools screened, 8% were positive by RT-PCR and their sequences showed that all strains contained the GLPSG and YGDD motifs which are conserved for HuCVs. Amino acid (aa) sequence analysis showed that these strains can be divided into 3 major genogroups. High conservation was observed in that one strain shares 100% of aa sequence with Southampton virus, another shares 99% with the Sapporo virus, and six strains share 90 to 95% with Snow Mountain virus. However, significant sequence variation was also found in other strains. This study indicates that all major genogroups of HuCVs are circulating in Korea.

• Plant Resources
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• 제1권2호
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• pp.92-97
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• 1998

An isolate of barley yellow mosaic virus(BaYMV-HN) obtained from Haenam, Korea was compared with two BaYMV strains. BaYMV-Ⅱ-1 from Japan and BaYMV-G from Germany. The sequence of the 3'-terminal 3817nucleotides[excluding the poly (A) tail] of RNA 1 of BaYMV-HN was determined to start within a long open reading frame coding for a part of the NIa-VPg polymerase(26 amino acids). NIa-Pro polymerase (343 amino acids), NIb polymerase(528 amino acids) and the entire capsid protein(297 amino acids), which is followed by a noncoding region(NCR) of 235 nucelotides. In the partial ORFs, BaYMV-HN shows higher sequence homology with BaYMV-Ⅱ-1(99.5%) than BaYMV-G(92.7%). The 3' non-coding regions of BaYMV-HN(235nt) shows higher nucleotide sequence homology with BaYMV-G(235nt)(99.6%) than BaYMV-Ⅱ-1(231nt)(97.0%). The 3' NIa-Pro protein sequence of BaYMV-HN shows higher amino acid sequence homology with BaYMV-Ⅱ-1(95.0%) than BaYMV-G(93.6%), but, NIb protein sequence of BaYMV-HN shows same all amino acid sequence. The capsid protein sequence of BaYMV-HN(297aa) shows same with BaYMV-Ⅱ-1, and shows higher nucleotide sequence homology with BaYMV-UK (from United Kingdom)(97.3%) than BaYMV-G(96.9%) and G2(96.9%). Difference of capsid protein amino acid were 0-9 between the Japan, United Kingdom and Germany and were 2-6 between all Korean isolates. Many of the amino acid differences are located in the N-terminal regions of the capsid proteins from 1 to 74 amino acid positions.

• Molecules and Cells
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• 제25권4호
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• pp.510-522
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• 2008

To construct the molecular systematics of the genus Megoura (Hemiptera: Aphididae), DNA based-identification was performed using four mitochondrial and three nuclear DNA regions: partial cytochrome c oxidase I (COI), partial tRNA-leucine + cytochrome c oxidase II (tRNA/COII), cytochrome b (CytB), partial 12S rRNA + tRNA-valine + 16S rRNA (12S/16S), elongation factor-1 alpha ($EF1{\alpha}$), and the internal transcribed spacers 1 and 2 (ITS1, ITS2). Pairwise sequence divergences between taxa were compared, and phylogenetic analyses were performed based on each DNA region separately, and the combined datasets. COI, CytB, $EF1{\alpha}$, ITS1, and ITS2 were relatively effective in determining species and resolving their relationships. By contrast, the sequences of tRNA/COII and 12S/16S were not able to separate the closely related species. CytB and $EF1{\alpha}$ gave better resolution with higher average sequence divergences (4.7% for CytB, 5.2% for $EF1{\alpha}$). The sequence divergence of COI (3.0%) was moderate, and those of the two ITS regions (1.8% for ITS1, 2.0% for ITS2) were very low. Phylogenetic trees were constructed by minimum evolution, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses. The results indicated that the phylogenetic relationships between Megoura species were associated with their host preferences. Megoura brevipilosa and M. lespedezae living on Lespedeza were closely related, and M. nigra, monophagous on Vicia venosa, was rather different from M. crassicauda, M. litoralis, and M. viciae, which are oligophagous on Lathyrus and Vicia. The three populations of M. crassicauda formed a clade separated from M. litoralis and M. viciae. Nevertheless M. litoralis and M. viciae, which are morphologically similar, were not separated due to negligible sequence divergence. We discuss the phylogenetic relationships of the Megoura, and the usefulness of the seven DNA regions for determining the species level phylogeny of aphids.

• Molecules and Cells
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• 제24권2호
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• pp.247-254
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• 2007

Improvement in the pharmacokinetic properties of short interfering RNAs (siRNAs) is a prerequisite for the therapeutic application of RNA interference technology. When injected into mice as unmodified siRNAs complexed to DOTAP/Chol-based cationic liposomes, all 12 tested siRNA duplexes caused a strong induction of cytokines including interferon ${\alpha}$, indicating that the immune activation by siRNA duplexes is independent of sequence context. When modified by various combinations of 2'-OMe, 2'-F, and phosphorothioate substitutions, introduction of as little as three 2'-OMe substitutions into the sense strand was sufficient to suppress immune activation by siRNA duplexes, whereas the same modifications were much less efficient at inhibiting the immune response of single stranded siRNAs. It is unlikely that Toll-like receptor 3 (TLR3) signaling is involved in immune stimulation by siRNA/liposome complexes since potent immune activation by ds siRNAs was induced in TLR3 knockout mice. Together, our results indicate that chemical modification of siRNA provides an effective means to avoid unwanted immune activation by therapeutic siRNAs. This improvement in the in vivo properties of siRNAs should greatly facilitate successful development of siRNA therapeutics.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.147.2-148
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• 2003

Complete nucleotide sequence of genome RNA of a Korean isolate of Pepper mottle virus (PepMoV-Vb) from field-collected diseased paprika (Capsicum annuum var grossum) was determined in this study. Symptoms of isolates of PepMoV were divided largely into two groups, vein banding (Vb) and vein clearing (Vc) patterns. PepMoV-Vb RNA consists of 9,640 nucleotides excluding the poly(A) tail. A single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3024 amino acids which is typical of the Potyvirus genus. The complete nucleotide sequence and coding regions of PepMoV-Vb were compared to that of 11 potyviruses within the genus Potyvirus. The overall nucleotide sequence identity was 94.7 and 94.1％ identical to PepMoV-C and PepMoV-FL, respectively. Full-length cDNAs of PepMoV-Vbl were synthesized from purified viral RNAs by RT-PCR and their genome structure was analysed by RFLP analysis. This is the first report on complete nucleotide sequence of PepMoV isolated from paprika in Korea.

• Applied Biological Chemistry
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• 제37권1호
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• pp.56-63
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• 1994

오이모자이크 바이러스(CMV)의 외피단백질 유전자의 일정한 염기서열을 보유하는 부분과 CMV RNA에 대항한 헤머헤드(hammerhead) 구조의 ribozyme을 만드는 올리고뉴클 레오타이드(oligonucleotide, nt)를 DNA 합성기를 이용하여 제조하였다. 올리고뉴클레오타이드의 양쪽가닥을 서로 합친 후 제한효소 BamHl과 SacI으로 처리하여 플라스미드 pBS SK(+)에 삽입하였고 CMV 기질과 ribozyme 클론의 염기서열을 결정하여 확인하였다. 기질과 ribozyme 클론 $1\;{\mu}g$ BssHII이나 SspI으로 처리한후 T7 RNA 합성효소를 이용하여 튜브내에서 전사반응을 실시하였다. 제한효소 BssHII를 처리한 경우 만들어진 기질 RNA의 크기는 176 nt 였는데 50 nt의 CMV RNA 염기, 6 nt의 Xbal 제한효소 염기, 120 nt의 벡터에서 비롯된 염기를 포함한다. Ribozyme RNA의 크기는 164 nt인데 38 nt의 ribozyme 염기부분과 그외는 기질의 것과 같은 염기를 포함한다. CMV 기질 RNA는 ribozyme RNA에 의하여 특이적으로 절단되어 96 nt와 80 nt 두개의 조각을 만들었다. 이러한 특이적 절반은$37^{\circ}C$ 보다 $55^{\circ}C$에서 더 빠르게 일어났다. SspI으로 처리한 경우 만들어진 기질 RNA(2234 nt)도 역시 위치 ribozyme에 의해 두조각으로 절반되었으며 SspI 처리 후 만들어진 ribozyme RNA(2222 nt)에 의해서 특이적으로 절단되었다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (A)
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• pp.685-687
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• 2002

RNA pseudoknot은 RNA 삼차 구조를 형성하는 중요한 구조요소일 뿐만 아니라, RNA 분자에서 중요한 역할을 한다. 지금까지 RNA pseudoknot 구조를 시각화하는 도구는 개발되어 있지 않기 때문에 대부분의 pseudoknot 구조의 시각화 작업은 수작업으로 이루어지고 있다. 본 논문은 RNA pseudoknot을 시각화를 위한 새로운 pseudoknot 표현 기법과 시각화 알고리즘에 대해서 소개한다. 새로운 표현기법은 모든 H-type pseudoknot을 uniform planar graph로 나타내고 RNA sequence의 진행방향을 따라가기가 쉽게 되어있다. 알고리즘을 이용하여 PseudoViewer라는 프로그램을 개발하였으며 PseudoViewer는 어떠한 시스템에서도 작동할 수 있는 Java로 구현되었다. 그 결과는 pseudoknot을 명확히 구분되고 보기 쉽도록 시각화됨을 보여준다.