• KSBB Journal
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• v.19 no.1
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• pp.42-49
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• 2004

A gene coding for epoxide hydrolase (EH) of Aspergillus niger LK, a fungus possessing the enantioselective hydrolysis activity for racemic epoxides, was characterized by phylogenetic analysis. The deduced protein of A. niger LK epoxide hydrolase shares significant sequence similarity with several bacterial EHs and mammalian microsomal EHs (mEH) and belongs to the a/${\beta}$ hydrolase fold family. EH from A. niger LK had 90.6% identity with 3D crystal structure of lqo7 in Protein Data Bank. Sequence comparison with other source EHs suggested that Asp$\^$l92/, Asp$\^$374/ and His$\^$374/ constituted the catalytic triad. Based on the multiple sequence comparison of the functional and structural domain sequence, the phylogenetic tree between relevant epoxide hydrolases from various species were reconstructed by using Neighbor-Joining method. Genetic distances were so far as 1.841-2.682 but characteristic oxyanion hole and catalytic triad were highly conserved, which means they have diverged from a common ancestor.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.2
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• pp.90-93
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• 1998

Cultured isolates of Prorocentrum minimum, P. micans, P. triestinum, P. balticum, Gymnodinium sanguineum, Alexandrium catenella, Scrippsiella trochoidea, and Heterosigma akashiwo from red tides in southern coast of Korea were phylogenetically compared on the basis of their 24S rRNA genes. For each isolate approximately 700 bp of 24S rDNA, encompassing D1 and D2 hypervariable domains, was amplified using the polymerase chain reaction and sequenced. The sequences were aligned with those reported in Genbank by using ClustalW program and phylogenetic tree was generated to show that morphospecies designations in the Alexandrium and Prorocentrum species are congruent with terminal taxa defined by phylogenetic analysis of the 24S rRNA fragment. Our results suggest that the molecular phylogeny approach could facilitate identification of domestic dinoflagellates which have ambiguous morphologies.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.13-17
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• 1999

Shigella sonnez is important causes of human enleric infcctions. S. sonnei KNIH104S was isolated from patient of shigellosis in Korea and previously reported. We cloned 1.7 kb BamHI fragment containing the asd gene encoding an aspartate $\beta$-semialdehyde dehydrogenase from chromosomal DNA of S. sonnei KNIH104S. This recombinant plasmid was named as pSAB17. E. coli $\chi$6097, an a d mutant, cannol grow on the LB medium without DL-$\alpha$, $\varepsilon$-diaminopimclic acid (50 pgiml) but E. coli x 6097(pSAB17) can grow on the same medium. We sequenccd the asd gene ol Shigella for the first time. The asd gcne was composed of 1,104 base pairs with ATG initiation codon and TAA termination codon. Sequence comparison of the asd gene exhibited 99.9% nucleolide sequence hornology with that of E. coli. Also, We constructed the balanced-lethal vector using pBluescrip SK(+) and asd gene of S. sonnei KNIH104S.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.221-225
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• 2004

Novel cytochrome P450 hydroxylase (CYP) genes were isolated and characterized from P. autotrophica cosmid DNA library using an actinomycete CYP-specific PCR product as a screening probe. The cosmids containing four unique CYP genes (pESK601, 602, 603, 604, 605) were identified, and the four CYP genes were completely sequenced to be homologous to other known Actinomycetes CYP genes involved in various secondary metabolic pathways. Among all novel actinomycete CYP genes found in P. autotrophica, the CYP genes present in pESK601 were revealed to be highly homologous to the CYP genes involved in polyene-type amphotericin and nystatin antibiotic biosynthesis. The nucleotide sequences of the CYP flanking region in pESK601 also revealed the polyene-type biosynthetic genes, implying the presence of a cryptic polyene-type antifungal biosynthetic gene cluster in P. autotrophica.

• Journal of fish pathology
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• v.17 no.2
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• pp.91-98
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• 2004

This study was performed for the identification of Streptococcus sp. from cultured flounders (Paralichthys olivaceus) showing streptococcosis in the Jeju island. We isolated 10 strains of Streptococcus iniae from the cultured olive flounders with streptococcosis. Isolated strains were identified in S. iniae since they have formed the expected band through performing PCR assay using specific primers, Sin-1 (5'-CTAGAGTACACATGTACT(AGCT)AAG-3') and Sin-2 (5'-GGATTTTCCACTCCCATTAC-3'). In addition to 16S-23S rRNA intergenic spacers (ISR), operon structure of isolated strains showed that all strains had three 16S-23S rRNA ISR band patterns. The 16S-23S rRNA ISR sequence of isolated strains showed 96% sequence identity with S. iniae (GenBank accession number AF 048773). This paper is the first report that S. iniae is associated with streptococcosis of Olive flounder in Korea.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.45-50
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• 2020

In this study, seafood products (n=26) sold on sushi buffet restaurants in the city of Wonju were monitored by analyzing sequences of DNA barcode markers (cytochrome c oxidase subunit I and 16S ribosomal RNA genes). NCBI BLAST database was screened with the barcode sequences analyzed as a query for species identification. The BLAST search revealed that fifteen samples (58%) analyzed were consistent with their labeling information; however, the ingredients used in seven samples (27%) were not compliant with their label information. In the case of these mislabeled products, ingredients for sutchi catfish sushi and cherry bass sashimi were identified as Pangasianodon hypophthalmus and Lampris guttatus, respectively. For Japanese flying-fish roe sushi and Pacific herring roe sushi, roe of Mallotus villosus was used as an ingredient. Amphioctopus fangsiao and A. membranaceus were used in octopus sushi and soybean-marinated squid products, respectively. This monitoring result can contribute to the protection of consumer rights and the reduction of fraudulent practices in the food industry.

• Korean Journal of Plant Taxonomy
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• v.41 no.2
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• pp.130-137
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• 2011

Pedicularis growing at Mt. Halla of Jeju Island is known as an endemic species of P. hallaisanensis Hurusawa. On the other hand, the plant is morphologically similar to P. amoena, P. spicata, and P. verticillata in gross morphology, so the taxonomic treatment of the taxon remains controversial. To clarify the taxonomic position of the plants, we examined external morphological characters and nuclear ribosomal DNA ITS sequences for P. hallaisanensis and its related species. The plants of Mt. Halla are clearly different from P. amoena and P. verticillata in the morphology of calyx lobes, the length of galea and lower lip, density of glandular hairs on plants, presences of the radical leaves after anthesis and molecular data. However, P. hallaisanensis is not clearly separated from P. spicata distributed in N. E. Asia on external morphological characters and DNA sequences of internal transcribed spacers. In this study, the morphological and molecular data suggested that P. hallaisanensis should be merged into the former species.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.116-119
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• 2016

Stable maintenance of telomere is required for cell proliferation and survival. Although telomerase is the primary means for telomere maintenance, recombination is another important pathway to maintain telomeres. In this study, we developed a genetic assay for telomere recombination using the internal $TG_{1-3}$ repeats present in subtelomeric regions of yeast. The recombination frequencies were dependent on the presence of the internal $TG_{1-3}$ repeats. PCR amplification of the regions near URA3 and CAN1 markers using genomic DNA isolated from $FOA^rCan^r$ colonies indicated that each isolate had lost the chromosome end including the markers. In addition, the recombination frequencies increased with longer internal $TG_{1-3}$ repeats. Our results suggest that the $FOA^rCan^r$ colony formation is the consequence of recombination between the internal and terminal $TG_{1-3}$ repeats.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.403-409
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• 1992

For the development of a glucanolytic yeast strain. the seceretion of endo-1.4-$\beta$-D-glucanase (CMCase) of Bacillus subtilis was performed in yeast using glucoamylase gene (STA1) of Saccharomyces diastaticus. A 1.7 kb-DNA fragment of STA1 gene containing authentic promoter, signal sequence, threonine serine-rich (TS) region and N-terminal region (98 amino acids) of mature glucoamylase was ligated to YEp 24. E. coli-yeast shuttle vector. And then. CMCase structural gene of B. subtilis was fused in frame with the 1.7 kb-DNA fragment of STA1 gene, resulting in recombinant plasmid pYES('24. Yeast transformant harboring pYESC24 had no CMCase activity. So. we deleted TS region and N-terminal region of mature glucoamylase existing between signal sequence and CMCase structural gene in pYESC24. consequently constructed recombinant plasmid pYESC11. The yeast transformed with the newly constructed recombinant plasmid pYESC11 efficiently secreted CMCase to extracellular medium. After 4 days culture. total CMCase activity of this transformant was 44.7 units/ml and over 93% of total CMCase activity was detected in culture supernatant.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.123-127
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• 2003

Sphingomonas chungbukensis DJ77 is able to metabolize phenanthrene as the sole carbon and energy source. The plasmid pUPX5 includes phnS gene encoding 2-hydroxychromene-2-carboxylate (HCCA) isomerase, which is needed for phenanthrene and naphthanene degradation. We determined the nucleotide sequence of DNA fragment of 3271 bp which included the phnS gene. The fragment included an open reading frame of 594 bp which has ATG initiation codon and TAA termination codon and GGAA ribosomal binding site. The predicted amino acid sequence of the enzyme consists of 198 amino acids. The deduced amino acid sequence of the phnS enzyme exhibited 94％ identity with that of the corresponding enzyme in Sphingomonas aromaticivorans F199. The phnS gene is located downstream and in the same operon as phnQ and phnR, encoding a 2,3-dihydroxybiphenyl 1,2-dioxygenase and a ferredoxin component of biphenyl dioxygenase, respectively.