• Journal of Yeungnam Medical Science
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• v.19 no.1
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• pp.1-10
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• 2002

With the establishment of rapid sequence analysis of 16S rRNA and the recognition of its potential to determine the phylogenetic position of any prokaryotic organism, the role of 16S rRNA similarities in the present species definition in bacteriology need to be clarified. Comparative studies clearly reveal the limitations of the sequence analysis of this conserved gene and gene product in the determination of relationship at the pathogenic strain level for which DNA-DNA reassociation experiments still constitute the superior method. Since today the primary structure of 16S rRNA is easier to determine than hybridization between DNA strands, the strength of the sequence analysis is to recognize the level at which DNA pairing studies need to be performed, which certainly applies to similarities of 97% and higher.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.734-738
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• 2005

A gene coding for xylanase from alkali-tolerant Bacillus alcalophilus AX2000 was cloned into Escherichia coli $DH5\alpha$ using pUC19. Among 2,000 transformants, one transformant showed clear zone on the detection agar plate containing oat-spells xylan. Its recombinant plasmid, named pXTY99, was found to carry 7.0 kb insert DNA fragment. When the nucleotide sequence of the cloned xylanase gene (xynT) was determined, xynT gene was found to consist of 1,020 base-pair open reading frame coding for a poly-peptide of 340 amino acids with a deduced molecular weight of 40 kDa. The coding sequence was preceded by a putative ribosome binding site, and the transcription initiation signals. The deduced amino acid sequence of xylanase is similar to those of the xylanases from Bacillus sp. Nl37 and B. stearothermophilus 21 with $61\%$ and $59\%$ identical residues, respectively.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.157-159
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• 1997

A 340-bp chitin synthase gene(CHS) fragment was cloned from the genomic DNA of Pyricularia oryzae using a PCR process with two primer DNAs corresponding to highly conserved sequences within fungal CHS genes. The entire DNA nucleotide sequences of the cloned DNA fragment were determined and analyzed. The amino acid sequences deduced from the nucleotide sequence of the amplified DNA fragment showed 86% homology to that of the Aspergillus fumigatus CHSE gene (9). Using this PCR-amplified DNA, about 2.3 kb of including the PCR fragment of CHSE gene was cloned from genomic library.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.142-158
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• 2013

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is widely utilized for greenhouse pollination in South Korea. Understanding the magnitude of genetic diversity and geographic relationships is of fundamental importance for long term preservation and utilization. As a first step, we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to the "DNA barcode" region and the complete internal transcribed spacer 2 (ITS2) of nuclear ribosomal DNA from 88 individuals collected in nine South Korean localities. The complete ITS2 sequences were longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated 112-bp long repeats. The 658-bp long mtDNA sequences provided only six haplotypes with a maximum sequence divergence of 0.61% (4 bp), whereas the ITS sequences provided 84 sequence types with a maximum sequence divergence of 1.02% (21 sites). The combination of the current COI data with those of published data suggest that the B. ignitus in South Korea and China are genetically a large group, but those in Japan can be roughly separated into another group. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population were found to exist among the South Korean populations of B. ignitus, which suggests panmixia. This finding is consistent with our understanding of the dispersal capability of the species.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.670-676
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• 2000

Several clones obtained from Serratia marcescens stimulated E. coli TP2139 (${\Delta}lac, \;{\Delta} crp$) cells to use maltose as a carbon source. The crp gene clone, pCKB12, was confirmed to stimulate the $\beta$-galactosidase activity, by Southern hybridization [31]. The nucleotide sequence of the crp region consisting of 1,979 bp was determined. The sequencing of the fragment led to the identification of two open reading frames: One of these, the crp gene, encoded 210 amino acid and the other encoded a truncated protein. The S. marcescens and E. coli crp genes showed a higher degree of divergence in their nucleotide sequence with 120 changes, however, the corresponding amino acid sequences showed only two amino acid differences. Yet, an analysis of the amino acid divergence revealed that the catabolite gene activator protein, the crp gene product, was the most conserved protein observed so far. Using a crp-lac protein fusion, it was demonstrated that S. marcescens CRP could repress its own expression, probably via a mechanism similar to that previously described for the E. coli crp gene.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.678-686
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• 1995

SecY is a central component of the protein export machinery that mediate the translocation of secretory proteins across the plasma membrane of Escherichia coli. In order to study the mechanism of protein secretion in Streptomyces, we have done cloning and sequencing of the Streptomyces coelicolor secY gene by using polymerase chain reaction method. The nucleotide sequence of the gene for SecY from S. coelicolor showed over 58% identity to that of M. luteus. The deduced amino acid sequences were highly homologous to those of other known SecY polypeptides, all having the potential to form 10 transmembrane segments, and especially second, fifth, and tenth segments were particularly conserved, sharing greater than 75% identity with W. lute s SecY. We propose that the conserved membrane-spanning segments actively participate in protein export. In B. subtilis and E. coli, the secY gene is a part of the spc operon, is preceded by the gene coding for ribosomal protein L15, and is likety coupled transcriptionally and translationally to the upstream L15 gene. In the other hand, secY gene of S. coelicolor and M. luteus have its own promoter region, are coupled translationally with adk gene and pr sented in adk operon.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.113.1-113
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• 2003

A potexvirus, Hosta virus X (HVX-Kr), causing mosaic and mottle symptoms was isolated from hosta plants (Hosta spp.), and its entire genome RNA sequence was determined. in Korea using cDNA library and RACE methods. The genome of HVX encodes five open reading frames coding for viral replicase, triple gene block (TGB), and viral coat protein (CP) from the 5'to 3' ends, which is a typical genome structure of potexviruses. The 3-terminal region of the virus includes the TGBI (26 kDa), TGB2 (13 kDa), TGB3 (8 kDa), and 23 kDa coat protein (CP) and the 3-nontranslated region (NTR). The CP gene of the type isolate of HVX (HVX-U) was amplified by RT-PCR and its nucleotide sequence was determined. The CPs of HVX-Kr and HVX-U had 100％ and 98.9％ identical amino acids and nucleotides, respectively. Most of the regions of the genome HVX had over 50％ nucleotide identical to other sequenced potexviruses. This is the first report of complete genome sequence information of HVX and molecular evidence supporting the virus as a distinct species of the genus Potexvirus.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.9-13
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• 2006

Objectives : To determine the DNA sequence of the 18S rRNA gene of the Rehmannia glutinosa and analyze it phylogenetically Methods : Dried root of the Rehmannia glutinosa was ground with a mortar and pestle. Glass beads(0.5 mm in diameter), TE buffer and SDS solution were added to that. The mixture was vortexed vigorously and extracted with the mixture of phenol, chloroform and isoamyl alcohol and with the mixture of the chloroform and isoamyl alcohol. The nucleic acids were precipitated with ethanol and resuspended in TE buffer. Contaminating RNA was digested with RNAse A and the DNA was purified further with the Geneclean Turbo Kit. This DNA was used as a template for amplification of the 18S rRNA gene by PCR. The PCR product was cloned in the pBluescript SK II plasmid by blunt-end ligation and the DNA sequence of the insert was determined. This DNA sequence was analyzed phylogenetically by the BLAST program. Results and Conclusion : Vortexing the ground powder of the dried plant root with glass beads during cell lysis improved recovery of DNA. The DNA sequence of the Rehmannia glutinosa 18S rRNA gene was determined and deposited at the GenBank as the accession number DQ469606. Phylogenetic analysis of that sequence showed the relationship between the members of the family of Scrophulariaceae and also the close relationship of the Buddleja davidii to the members of the Scrophulariaceae family.

• BMB Reports
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• v.31 no.6
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• pp.565-571
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• 1998

The expression of the endogenous human apolipoprotein(apo)E gene was significantly induced when HepG2 cells were treated with exogenous 25-hydroxy-cholesterol. This sterol-mediated apoE gene upregulation appears to require the participation of a positive element for the apoE gene transcription (PET) ( -169/ -140), a core sequence of upstream regulatory element (URE)1 enhancer of the human apoE gene. This PET was renamed as sterol regulatory element (SRE)4 based on its new role as a sensor for the level of intracellular sterol. Furthermore, a gel mobility shift analysis showed that binding activity of the SRE4 binding protein (BP) obtained from HepG2 cells was induced by sterol treatment, while that from either MCF7 or BT20 cells remained unchanged. Binding activity of SRE4BP was also induced in mouse macrophage cells, J774A.1, by sterol treatment, but it was drastically reduced when cells were subjected to treatment of AY-9944, a potent inhibitor for sterol synthesis. However, binding activity of Spl, which is a co-binding protein to the SRE4 region, remained the same in either condition, suggesting that SRE4BP (formally known as PETBP) may be mainly responsible for the sterol-mediated regulation of the apoE gene expression. Deletion analysis of the core binding site of SRE4BP by gel mobility shift assays showed that the minimal sequence of the SRE4BP binding appears to reside between -157 and -140, confirming the identity of SRE4 with the previously determined core sequence of URE1.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.275-275
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• 2002

Pseudomonas sp. S-47 is capable of catabolizing 4-chlorobenzoate (4CBA) as carbon and energy sources under aerobic conditions via the mesa-cleavage pathway. 4CBA-dioxygenase and 4CBA-dihydrodiol dehydrogenase (4CBA-DD) catalyzed the degradation af 4CBA to produce 4-chlorocatechol in the pathway. In this study, the xylL gene encoding 4CBA-DD was cloned from the chromosomal DNA of Pseudomonas sp. S-47 and its nucleotide sequence was analyzed. The xylL gene was found to be composed of 777 nucleotide pairs and to encode a polypeptide of 28 kDa with 258 amino acid residues. The deduced amino acid sequence of the dehydrogenase (XylL) from strain S-47 exhibited 98% and 60% homologies with these of the corresponding enzymes, Pseudomonas putida mt-2 (XyIL) and Acinetobacter calcoaceticus (BenD), respectively. However, the amino arid sequences show 30% or less homology with those of Pseudomonas putida (BnzE), Pseudomonas putida Fl (TodD), Pseudomonas pseudoalcaligenes KF707 (BphB), and Pseudomonas sp. C18 (NahB). Therefore, the 4CBA-dihydrodiol dehdrogenase of strain S-47 belongs to the group I dehydrogenase involved in the degradation of mono-aryls with a carboxyl group.