• Plant Biotechnology Reports
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• 제3권2호
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• pp.139-145
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• 2009

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we isolated NtMET1 from Nicotiana tabacum cv. Havana (SR1) and obtain transgenic plants that reduced MET1 expression level with the double-strand RNA (dsRNA) MET1 gene. Transgenic tobacco plants showed dwarf and abnormal flower development when compared with the wild type. Using methylation-sensitive amplified polymorphism (MSAP) analysis, the patterns of cytosine methylation in transformed plants and the wild type were compared. MseI/HpaII selection primers showed an interesting polymorphism, and 153 DNA bands of interest were detected. Among these, 30 selective fragments were sequenced and analyzed with a BLAST search by successful MSAP modifications. The homology search showed that the transposons and tandem repeated sequences were related to the phenotypes. These results suggested that the decreased degree of methylation by dsRNA strategy caused abnormal growth and development in N. tabacum.

• BMB Reports
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• 제49권6호
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• pp.349-354
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• 2016

The archaeon Sulfolobus solfataricus P1 carboxylesterase is a thermostable enzyme with a molecular mass of 33.5 kDa belonging to the mammalian hormone-sensitive lipase (HSL) family. In our previous study, we purified the enzyme and suggested the expected amino acids related to its catalysis by chemical modification and a sequence homology search. For further validating these amino acids in this study, we modified them using site-directed mutagenesis and examined the activity of the mutant enzymes using spectrophotometric analysis and then estimated by homology modeling and fluorescence analysis. As a result, it was identified that Ser151, Asp244, and His274 consist of a catalytic triad, and Gly80, Gly81, and Ala152 compose an oxyanion hole of the enzyme. In addition, it was also determined that the cysteine residues are located near the active site or at the positions inducing any conformational changes of the enzyme by their replacement with serine residues.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.457-462
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• 2003

The complete nucleotide sequence of a plasmid, pMG1, isolated from Bifidobacterium longum MG1 has been determined. This plasmid, composed of 3,862 base pairs with 65.1% of G+C content. harbors two major open reading frames (ORF) encoding putative proteins of 29 kDa (ORF I) and 71 kDa (ORF II). ORF I showed relatively high amino acid sequence homology with replication proteins of other plasmids from Gr Im-positive and -negative bacteria. Upstream of ORF I, four sets of tandem repeat sequences resembling the iteron structure of related plasmids were found. S1 endonuclease treatment and Southern blot analysis revealed that pMG1 accumulates single-stranded DNA (ssDNA) intermediate, which indicate i the rolling circle replication (RCR) mechanism of this plasmid. Homology search indicated that ORF II encodes plasmid mobilization protein, and the presence of highly conserved oriT sequence in the upstream of this gene supported this assumption. RT-PCR showed that only ORF I is expressed in vivo. Based on these results, pMG 1 was exploited to construct a shuttle vector, pBES2. It was successfully transformed into Bifidobacterium and maintained stably.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.870-872
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• 1999

The ubiquinone and G+C contents of the bioflocculant-producing fungus, a new Aspergillus strain, were detennined using high-perfonnance liquid chromatography. The internal transcribed spacers 1 and 2 (ITS1 and ITS2), and the 5.8S ribosomal DNA (rDNA) of the strain were amplified and sequenced. The strain contained ubiquinone-l0($H_2$)as a major quinone and the G+C content was 49 mol%. A phylogenetic analysis of the ITS regions indicated that the strain belonged to the genus Aspergillus according to its previously classified morphological characteristics. Based on a sequence homology search, the strain was most closely related to Petromyces muricatus (anamorph, A. muricatus; accession number, AJ005674). The sequence of a new Aspergillus strain in ITS1 and ITS2, and 5.8S rDNA showed 97% homology to P. muricatus. Therefore, the strain is believed to be a new bioflocculant-producing Aspergillus strain.

• International Journal of Industrial Entomology and Biomaterials
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• 제21권1호
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• pp.127-132
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• 2010

We have characterized full-length cDNA encoding Gall-6-tox protein, which was cloned from the fat body of the immunized Galleria mellonella larvae. The cloned cDNA of Gall-6-tox consists of 1301 nucleotides and contained an open reading frame of 891 nucleotides corresponding to a protein of 296 residues that includes a putative 16-residue signal sequence and a 280-residue mature peptide with a calculated mass of 30,707.73 Da. The deduced mature peptide contains conserved tandem repeats of six cysteine-stabilized alpha beta ($Cs{\alpha}{\beta}$) motifs, which was detected in scorpion toxins and insect defensins. In the sequence homology search, mature Gall-6-tox showed 34% and 28% amino acid sequence homology with Bomb-6-tox from Bombyx mori and Spod-11-tox from Spodoptera frugiperda, respectively. Gall-6-tox orthologs were only found in Lepidopteran species, indicating that this new immune-related gene family is specific to this insect order. RT-PCR analysis revealed that Gall-6-tox was expressed primarily in the larval fat bodies, hemocytes, and midgut against invading bacteria into hemocoel. Moreover, the expression time course of Gall-6-tox was examined up to 24 h in the fat bodies and midgut after injection of E. coli. Altogether, these results suggest that Gall-6-tox is derived from defensins and Gall-6-tox may play a critical role in Lepidoptera immune system.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.278-288
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• 2019

In the present investigation, we attempted to design a protocol to develop a hybrid protein with better bioremediation capacity. Using in silico approaches, a Hybrid Open Reading Frame (Hybrid ORF) is developed targeting the genes of microorganisms known for degradation of organophosphates. Out of 21 genes identified through BLAST search, 8 structurally similar genes (opdA, opd, opaA, pte RO, pdeA, parC, mpd and phnE) involved in biodegradation were screened. Gene conservational analysis categorizes these organophosphates degrading 8 genes into 4 super families i.e., Metallo-dependent hydrolases, Lactamase B, MPP and TM_PBP2 superfamily. Hybrid protein structure was modeled using multi-template homology modeling (3S07_A; 99%, 1P9E_A; 98%, 2ZO9_B; 33%, 2DXL_A; 33%) by $Schr{\ddot{o}}dinger$ software suit version 10.4.018. Structural verification of protein models was done using Ramachandran plot, it was showing 96.0% residue in the favored region, which was verified using RAMPAGE. The phosphotriesterase protein was showing the highest structural similarity with hybrid protein having raw score 984. The 5 binding sites of hybrid protein were identified through binding site prediction. The docking study shows that hybrid protein potentially interacts with 10 different organophosphates. The study results indicate that the hybrid protein designed has the capability of degrading a wide range of organophosphate compounds.

• 한국균학회지
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• 제39권1호
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• pp.31-38
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• 2011

현재 70개 이상의 느타리 품종이 유통되어 재배되고 있다. 본 연구에서는 81개 품종을 수집하여 핵산지문법으로 분석하였다. 이중 수한과 그 유사품종에서 특이하게 나타나는 밴드를 이용하여 수한 품종에 특이적인 SCAR marker로 개발하였다. 수한 품종 특이 band에 대한 clone을 기존에 알려진 유전자 염기서열과 유사성이 있는지를 확인한 결과 POMFBO1 Pleurotus ostreatus cDNA clone MFB02-A05, mRNA sequence와 92%의 homology를 나타냈고, 등록된 아미노산 서열과의 유사성을 확인한 결과 큰졸각버섯인 Laccaria bicolor의 predicted protein과 가장 높은 sequence homology (BlastX score = 73.9, E value = $5e^{-25}$)를 보였다. 본 연구를 통하여 개발된 수한특이 마커는 정확한 품종구분이 요구되는 종균유통 과정에서 수한계통 품종을 구분하는 유용한 마커로 이용될 것으로 기대된다.

• 생명과학회지
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• 제17권8호통권88호
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• pp.1034-1038
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• 2007

하이퍼리신(Hypericin, HyH)은 예로부터 성 요한의 풀(St. John's Wort)로 널리 알려져 있는 서양고추나물(Hypericum perforatum)에서 추출되는 약리성분이다. 서양고추나물은 국내에서는 자생하지 않으나 같은 속의 고추나물(H. erectum) 등이 이속에 속하며 우리나라에 자생한다 . 고추나물을 조직배양으로 RNA를 추출하고 cDNA를 합성한 후 Hyp 유전자를 추출하여 서열화한 결과, 전체 크기는 732 bp로 나타났으며 서양고추나물의 HyH-1과 거의 99.8% 서열 일치를 나타내었다. 이 서열의 152개 아미노산 역시 서양고추나물의 항산화효소와 98% 일치하였으며 자작나무와 능금속 식물에서 유발되는 알레르기 유발유전자와 약 60% 일치를 나타내었다. 본 연구 결과 우울증치료제로 사용되는 하이퍼리신 추출에 우리나라 자생종인 고추나물이 이용될 수 있을 것으로 사료된다.

• 한국균학회지
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• 제26권3호통권86호
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• pp.314-320
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• 1998

mRNA의 differential display방법에 의해 여름느타리 자실체의 상처 또는 자외선 처리시 발현되는 약 0.4kb의 cDNA 단편을 분리하였다. 이 cDNA 단편의 염기서열 분석결과 세포분열 촉진에 관여하는 cdc2-related protein kinase gene과 상당부분 유사성을 보였으며 RT-PCR 방법을 이용한 분리 유전자의 발현 실험을 통해 이 유전자가 정상 생장 환경에서는 갓, 대, 균사 등 모든 부위에서 기본적인 발현상태를 유지하고 있으며 기계적 상처 또는 자외선 처리에 의해 그 발현이 증폭됨을 확인하였다. 이러한 결과를 통해 향후 분리된 유전자의 연구를 통한 버섯 병 방어 관련 신호 전달 체계 분석에 대한 가능성을 검토해 보았다.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.85-90
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• 2004

Nickel(II) compounds are carcinogenic metals which induce genotoxicity and oxidative stress through the generation of reactive oxygen species. In search of new molecular pathways toward understanding the molecular mechanism of nickel(II)-induced carcinogensis, we performed mRNA differential display analysis using total RNA extracted from nickel(II) acetate-treated normal rat kidney cells (NRK-52E). Cells were exposed for 3 days to 160 and 240 uM nickel(II) concentrations. cDNAs corresponding to mRNAs for which expression levels were altered by nickel(II) were isolated, sequenced, and followed by a GenBank Blast homology search. Specificity of differential expression of cDNAs was determined by RT-PCR and Western blot analysis. Two of them (SH3BGRL3 and FHIT) were down-regulated and one (metallothionein) was up-regulated by nickel(II) treatment. The expression of these mRNAs were nickel(II) concentration-dependent. The levels of FHIT and metallothionein proteins were also consistent with the results for mRNAs. Overall, although the fundamental questions related to function of these genes in nickel(II)-mediated carcinogenicity are not answered, our study suggests that they can be interesting candidates for studies of molecular mechanisms of nickel(II) carcinogenesis.