• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1189-1196
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• 2005

The cyclohexanol dehydrogenase (ChnA), produced by Rhodococcus sp. TK6, which is capable of growth on cyclohexanol as the sole carbon source, has been previously purified and characterized. However, the current study cloned the complete gene (chnA) for ChnA and its flanking regions using a combination of a polymerase chain reaction (PCR) based on the N-terminal amino acid sequence of the purified ChnA and plaque hybridization from a phage library of Rhodococcus sp. TK6. A sequence analysis of the 5,965-bp DNA fragment revealed five potential open reading frames (ORFs) designated as partial pte (phosphotriesterase), acs (acyl-CoA synthetase), scd (short chain dehydrogenase), stp (sugar transporter), and chnA (cyclohexanol dehydrogenase), respectively. The deduced amino acid sequence of the chnA gene exhibited a similarity of up to $53\%$ with members of the short-chain dehydrogenase/reductase (SDR) family. The chnA gene was expressed using the pET21 a(+) system in Escherichia coli. The activity of the expressed ChnA was then confirmed (13.6 U/mg of protein) and its properties investigated.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1337-1345
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• 2005

Vibrio vulnificus is the causative agent of foodborne diseases such as gastroenteritis and life-threatening septicemia. Microbial pathogenicity is a complex phenomenon in which expression of numerous virulence factors is frequently controlled by a common regulatory system. In the present study, a mutant exhibiting decreased cytotoxic activity toward intestinal epithelial cells was screened from a library of V. vulnificus mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, an open reading frame, fexA, a homologue of Escherichia coli areA, was identified and cloned. The nucleotide and deduced amino acid sequences of the fexA were analyzed, and the amino acid sequence of FexA from V. vulnificus was $84\%\;to\;97\%$ similar to those of AreA, an aerobic respiration control global regulator, from other Enterobacteriaceae. Functions of the FexA were assessed by the construction of an isogenic mutant, whose fexA gene was inactivated by allelic exchanges, and by evaluating its phenotype changes in vitro and in mice. The disruption of fexA resulted in a significant alteration in growth rate under aerobic as well as anaerobic conditions. When compared to the wild-type, the fexA mutant exhibited a substantial decrease in motility and cytotoxicity toward intestinal epithelial cell lines in vitro. Furthermore, the intraperitoneal $LD_{50}$ of the fexA mutant was approximately $10^{1}-10^{2}$ times higher than that of parental wild-type. Therefore, it appears that FexA is a novel global regulator controlling numerous genes and contributing to the pathogenesis as well as growth of V. vulnificus.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.450-456
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• 2006

Pseudomonas fluorescens MC07 is a growth-promoting rhizobacterium that suppresses mycelial growth in fungi such as Rhizoctonia solani, Pythium ultimum, Fusarium oxysporum, and Phytophthora capsici. To determine the role of the bacterium's antifungal activity in disease suppression, we screened 2,500 colonies generated by Tn5lacZ insertions, and isolated a mutant 157 that had lost antifungal activity. The EcoRI fragment carrying Tn5lacZ was cloned into pBluescript II SK(+) and used as a probe to isolate wild-type clones from a genomic library of the parent strain, MC07. Two overlapping cosmid clones, pEH4 and pEH5, that had hybridized with the mutant clone were isolated. pEH4 conferred antifungal activity to the heterologous host P.fluorescens strain 1855.344, whereas pEH5 did not. Through transposon mutagenesis of pEH4 and complementation analyses, we delineated the 14.7-kb DNA region that is responsible for the biosynthesis of an antifungal compound. DNA sequence analysis of the region identified 11 possible open reading frames (ORF), ORF1 through ORF11. A BLAST search of each putative protein implied that the proteins may be involved in an antifungal activity similar to polyketides.

• Applied Biological Chemistry
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• 제45권4호
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• pp.203-206
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• 2002

${\gamma}-Tocopherol$ methyltransferase(TMT)는 토코페롤 생합성 대사의 마지막 단계인 감마 토코페롤을 알파 토코페롤로 변환하는데 관여하는 효소이다. 들깨의 미성숙 종자 cDNA유전자 은행에서 TMT로 추정되는 유전자를 분리하였으며 이 유전자는 1369개의 염기와 367개의 아미노산으로 구성되었으며 분자량은 약 42kDa의 추정된다. 이 cDNA는 Genbank와 상동성 분석결과 애기장대의 TMT유전자와 아미노산 수준에서 60% 정도의 상동성을 가지고 있으며 methyltransferase domain과 S-adenosyl methionine binding domain을 가지고 있으므로 TMT 유전자로 추정했다. 이 유전자의 특성을 알기 위하여 완전한 크기를 가지는 TMT유전자를 대장균에서 발현하고 invitro에서 효소의 활성을 측정하였다.

• 한국어병학회지
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• 제14권2호
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• pp.59-64
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• 2001

두툽상어의 간조직 cDNA library의 EST를 통해 중금속의 세포내 농도 조절과 환경으로부터 흡수한 유해 중금속의 해독작용 등의 기능을 수행하는 MT 유전자를 cloning하였다. 염기서열 분석 결과 두툽상어의 MT 유전자는 204bp의 coding 영역과 182bp의 3'UTR 영역으로 구성되어 있었으며, 종결코돈 이후 162bp의 polyadenylatin 신호서열과 이로부터 15bp 이후의 poly(A)서열 등이 확인되었다. 염기서열로부터 유추한 68개의 아미노산 서열에는 다른 척추동물에서와 같이 Cys 잔기가 전체의 29.4%(20/68)로 풍부하였으며, 아미노산 서열수준에서 포유류와는 43~54%, 어류들과는 41~45%의 상동성을 나타냈었다. 특히 20개의 Cys은 어류와 18개가 다른 척추동물과는 19개가 잘 보존되어 있었다. 두툽상어 MT는 특이하게 모든 척추동물에서 잘 보존된 $\beta$-domain 끝 쪽의 9번째 Cys앞에 5개의 아미노산을 더 갖고 있었으며, 경골어류 MT의 특징인 4번째 위치의 gap이 없고, 18번째 Cys의 위치가 어류와 달리 다른 척추동물들과 같았다. 또한 C 말단의 아미노산 잔기가 다른 생물체와는 모두 다른 Ser을 갖는 특징을 나타내었다. 이와 같은 두툽상어 MT유전자의 특징들은 연골어류의 분자적 진화과정을 알 수 있는 분자 표지유전자로 이용할 수 있을 것이다.

• 한국실내디자인학회논문집
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• 제14권6호
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• pp.177-184
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• 2005

The 21st Century Museum of Contemporary Art, Kanazawa as a regional public culture facility is the place where it is possible to think over the roles and meanings of a museum. The urn of this research is to provide information for exploring a desirable direction of the design of a regional museum by analyzing the architectural meanings and public property of the 21st Century Museum of Contemporary Art, Kanazawa. In addition, we arranged the totes and meanings of a regional museum and the concept of the public property in architecture. We also analyzed the architectural quality and the expression of the public property in this museum, as well as the value and meaning of a museum through field researches. The results of this research are as follows. First, this museum breaks with the existing stereotyped Idea to be a space open to the citizens. It secures a wide public space and provides the convenience of access and every facility for citizens. Second, the floor plan is divided into the interchanging area for citizens and an exhibition area; the outskirts of the inside of the museum are planned to be used free of charge for an interchanging space of citizens as a public-owned space of citizens. Third, the public-owned space of citizens includes a citizen exhibition hall, an art library, a kids studio and rest space, which ate all designed lot everyone to enjoy freely. Last, the exterior shape of the museum is simple but harmonize with the surroundings. It has an unique shape showing the local identity, and its most special properties are the convenience of access, introduction of a free space inside, and security of a huge space for children and citizens.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.743-749
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• 2004

The gene encoding human serum albumin (HSA) was cloned from human liver cDNA library by PCR. The HSA cDNA in size of 2,176 bp, including 1,830 bp of open reading frame, was cloned into the plasmid carried with the 5'flanking sequence of goat $\beta$-casein gene (-4,044 to +2,025 bp) to get a tissue specific expression vector in mammary gland named pGB562/HSA (12.5 kb). A 9.6 kb DNA fragment in which the sequence is in order of goat $\beta$-casein gene regulatory sequence, HSA cDNA and SV40 polyadenylation signals was isolated from the pGB562/HSA by SacI and DraIII cutting, and used to microinject into the pronuclei of mouse fertilized eggs to produce transgenic mice. Three transgenic mice (2 female and 1 male) were identified by PCR and dot Southern blot analysis. The copy numbers of integrated transgene were more than 10 copies in line #21 and #26 as well as over 50 copies in line #31 of transgenic mice. HSA protein collected from the milk of lactating transgenic mice was confirmed by immuno-detection of Western and slot blot. The concentrations of HSA in the milk were from 0.05 to 0.4 mg/ml. An obvious antigen and antibody conjugate could be observed in immunohistochemical stain of mammary gland tissue from lactating day 11 of HSA transgenic mice. The transmission of transgene and its expression was recognized according to the results of RT-PCR and sequences analyses of their progeny.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1260-1268
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• 2014

Screening of a gene library from Paenibacillus sp. PBS-2 generated in Escherichia coli led to the identification of a clone with lipolytic activity. Sequence analysis showed an open reading frame encoding a polypeptide of 378 amino acid residues with a predicted molecular mass of 42 kDa. The esterase displayed 69% and 42% identity with the putative ${\beta}$-lactamases from Paenibacillus sp. JDR-2 and Clostridium sp. BNL1100, respectively. The esterase contained a Ser-x-x-Lys motif that is conserved among all ${\beta}$-lactamases found to date. The protein PBS-2 was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at $18^{\circ}C$. The enzyme is a serine protein and was active against p-nitrophenyl esters of $C_2$, $C_4$, $C_8$, and $C_{10}$. The optimum pH and temperature for enzyme activity were pH 9.0 and $30^{\circ}C$, respectively. Relative activity of 55% remained at up to $5^{\circ}C$ with an activation energy of 5.84 kcal/mol, which indicates that the enzyme is cold-adapted. Enzyme activity was inhibited by $Cd^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ ions. As expected for a serine esterase, activity was inhibited by phenylmethylsulfonyl fluoride. The enzyme was remarkably active and stable in the presence of commercial detergents and organic solvents. This cold-adapted esterase has potential as a biocatalyst and detergent additive for use at low temperatures.

• 정보관리학회지
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• 제26권2호
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• pp.65-82
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• 2009

본 연구에서는 대학강좌에서 학생들의 소셜 북마킹 도구에 대한 인식 및 사용 행태를 분석하였다. 소셜 북마킹의 가치에 대한 최근 활발한 논의에도 불구하고 실제 이용자들이 어떻게 소셜 북마킹을 사용하는가에 대해서는 알려진 바가 많지 않다. 본 연구는 수업에서 학생들의 소셜 북마킹 도구인 딜리셔스 사용 행태와 인식을 바탕으로 소셜 북마킹이 제시하는 가치들이 실제에서 어떻게 나타나는지를 조사하였다. 학생들은 태깅, 기술, 네트워크의 기능을 소극적으로 사용하고 있었다. 이용자는 여전히 개인 정보 수집 및 관리의 도구로써 소셜 북마킹을 사용하고 있었으며, 소셜 북마킹 도구는 정보의 사용 및 재사용성은 향상시키고 있었으나 소셜 북마킹 도구가 지향하는 협력기반 정보공유, 협력기반 커뮤니티 구축 및 도메인 검색의 가치는 충분히 실현되지 못하고 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.258-263
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• 2000

2-Hydroxy-6-oxo-6phenylhexa-2,4-dienoate (HOPDA) hydrolase catalyzes the hydrolytic cleavage of HOPDA to bemzpate and 2-hydroxypenta-2, 4-dienoate (HPD) during microbial catabolism of biphenyl and polychlorinated biphenyls. A HOPDA hydrolase gene (pcbD) was isolated from the genomic library of Pseudomonas sp. P20 and designated as pCNUO1201; a 7.5-kb XbaI DNA fragment from Pseudomonas sp. P20 was inserted into the pBluescript SK(+) XbaI site. E. coli HB101 harboring pCNU1201 exhibited HOPDA hydrolase activity. The open reading frame (ORF) corresponding to the pcbD gene consisted of 855 base pairs with an ATG initiation codon and a TGA termination codon. The ORF was preceded by a rebosome-binding sequence of 5'-TGGAGC-3' and its G+C content was 55 mol%. The pcbD gene of Pseudomonas sp. P20 was located immedeately downstream of the pcbC gene encoding 2,3- dihydroxybiphenyl 1,2-dioxygenase, and approximately 4-kb upstream of the pcbE gene encoding HPD hydratase. The pcbK gene was able to encode a polypeptide with a molecular weight of 31,732 containing 284 amino acid residues. The deduced amino acid sequence of the HOPDA hydrolase of Pseudomonas sp. P20 exhibited high identity (62%) with those of the HOPDA hydrolases of P. putida KF715, P. pseudoalcaligenes KF707, and Burkholderia cepacia LB400, and also significant homology with those of other hydrolytic enzymes including esterase, transferase, and peptidase.