• Applied Biological Chemistry
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• 제31권3호
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• pp.219-225
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• 1988

Avian Sarcoma Virus의 plasmid DNA중(中)의 역 이사효소의 유전자(遺傳子)를 온도의존성(溫度依存性) 발현(發現) vector인 pPL-lambda에 cloning하여 온도(溫度)에 민감한 phage ${\lambda}$의 repressor인 cI857 gene을 갖고 있는 bacteriophage lysogen인 N4830에 transformation시켰다. transformant를 pL promoter의 발현(發現)을 억제(抑制)하는 저온(低溫)$(28^{\circ}C)$에서 배양(培養)시킨 뒤, 이 repressor를 억제(抑制)하여 transcription을 촉진(促進)하게 하는 고온(高溫)$(42^{\circ}C)$에서 배양(培養)시킨 다음 균체(菌體)를 회수(回收)하여 RNA를 추출(抽出)하고 분석(分析)을 한 결과(結果) 도입(導入)된 역전사 효소 유전자(遺傳子)의 전사(轉寫)가 고온(高溫)에서 증대(增大)되었다.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.408-412
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• 2008

FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1) in Arabidopsis are homologous proteins that perform opposite functions: FT is an activator of flowering, and TFL1 is a repressor. It was shown before that change of a single amino acid (His88) of TFL1 to the corresponding amino acid (Tyr) of FT is enough to convert the floral repressor to an activator. However, structural basis of the functional conversion has not been understood. In our molecular dynamics simulations on modified TFL1 proteins, a hydrogen bond present in native TFL1 between the His88 residue and a residue (Asp144) in a neighboring external loop became broken by change of His88 to Tyr. This breakage induced conformational change of the external loop whose structure was previously reported to be another key functional determinant. These findings reveal that the two important factors determining the functional specificities of the floral regulators, the key amino acid (His88) and the external loop, are correlated, and the key amino acid determines the functional specificity indirectly by affecting the conformation of the external loop.

• 한국버섯학회지
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• 제10권3호
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• pp.120-128
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• 2012

표고균사에서 갈변시기를 조절하고 확인할 수 있는 유전공학적 시스템을 개발하여 톱밥재배용 표고균주를 조기에 선별할 수 있도록 표고균사가 갈변되는 동안 균사상태에서 특이적으로 발현되는 유전자를 분리하기 위하여 갈변되지 않은 균사와 갈변이 완전히 이루어진 균사에서 differential display를 실시하였다. 그 결과 이들 균사로부터 특이적으로 발현되는 두 개의 1.6kb와 1.2kb의 cDNA clone을 선발하여 염기서열을 분석하였다. 이 중 1.6kb의 cDNA단편은 Dugenia polichroa로부터 분리된 microsatellites 유전자와 100%의 상동성을 나타냈다. 그러나 1.2kb의 cDNA 단편은 3'부위에 poly A tail과 5 부위에 partial open reading frame를 가지고 있어 이를 primer로 제작한 후 갈변되지 않은 균사와 갈변이 이루어진 균사에서 RT-PCR을 실시하여 본 결과 갈변이 되지 않은 백색의 균사에서 발현이 확인되었다. 1.2kb의 cDNA 단편의 5' 부위의 염기서열 분석은 110개의 아미노산으로 구성된 partial open reading frame으로 나타났다. 이 유전자를 DNASIS database에서 상동성을 비교해 본 결과 Arabidopsis thaliata에서 분리된 dTDP-glucose 4,6-dehydratases 유전자와 DNA 수준에서는 66.7%, 아미노산 수준에서는 69.2%의 높은 상동성을 나타내었다. 갈변에 관련된 특이 유전자(BCR gene)를 확인하였다. 이 유전자는 산화 stress에 대해 저항성을 나타내는 기능을 가진 것으로 알려져 있어 표고 균사가 갈변될 때 repressor로서 작용할 것으로 생각된다. 따라서 이 유전자를 BCR (Brown Color Repressor) 유전자라고 명명하였다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1997년도 제37회 춘계학술발표대회
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• pp.60.1-60.1
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• 1997

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2000년도 제17회 학술발표회
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• pp.5-5
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• 2000

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.9-11
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• 2000

• 미생물학회지
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• 제29권2호
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• pp.80-84
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• 1991

We cloned and expressed hepatitis B viral core antigen (HBcAg) gene in E. coli using $P_{L}$ promoter system. For optimal expression of the gene, we undertook the studies on the effects of the distance between Shine-Dalgarno (SD) sequence and start codon, copy number of repressor gene, induction temperature, and the stability of the core antigen. The results demonstrated that the induction at 37.deg.C was more efficient than at 42.deg.C, and the 11 base pairs (bp) distance between SD sequence and start codon of HBcAg gene was more efficient than the 15 bp distance in E. coli. The copy number of cI857 repressor gene did not influence on the expression of HBcAg, and the expression level of HBcAg in mutant type (low protease activity) and wild type strains was almost the same. The produced core antigen appeared to be HBcAg not HBeAg judged by two different radioimmunoassat (RIA) kits. This result suggested that the antigen was stable in E. coli.i.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.408-413
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• 1997

It was studied in order to improve the yield of serrapeptase production in fermentation that organic nitrogen sources play important roles not only as inducer, repressor and activator, but also nitrogen sources. From the investigation of the effect of Na-caseinate on the induction of serrapeptase production, it was elucidated that real inducer was leucine and strong repressor was cysteine, which were produced through hydrolysis of proteins. Serrapeptase production was strongly induced by Na-caseinate in culture time 12 hrs, but was weakly induced before and after that time. Therefore fed batch culture where partial amount of Na-caseinate is added in 12 hrs, is better than batch culture where total amount of Na-caseinate is added at the beginning. Cysteine, methionine, MgSO$_{4}$, and so on, sulfur-containing materials, repressed the serrapeptase production. In the addition of mineral salts, chlorinated salts is better than sulfated salts because of sulfur repression. The synergic effect of soybean meal with Na-caseinate on the serrapeptase production resulted from Mn$^{2+}$ contained in soybean meal, of which the optimal concentration is 4 mM in enzyme production.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2002년도 학술발표대회
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• pp.94-94
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• 2002