• Journal of Microbiology
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• 제43권4호
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• pp.354-360
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• 2005

Heat-labile enterotoxin B subunit (LTB) of enterotoxigenic Escherichia coli (ETEC) is both a strong mucosal adjuvant and immunogen. It is a subunit vaccine candidate to be used against ETEC-induced diarrhea. It has already been expressed in several bacterial and plant systems. In order to construct yeast expressing vector for the LTB protein, the eltB gene encoding LTB was amplified from a human origin enterotoxigenic E. coli DNA by PCR. The expression plasmid pLTB83 was constructed by inserting the eltB gene into the pYES2 shuttle vector immediately downstream of the GAL1 promoter. The recombinant vector was transformed into S. cerevisiae and was then induced by galactose. The LTB protein was detected in the total soluble protein of the yeast by SDS-PAGE analysis. Quantitative ELISA showed that the maximum amount of LTB protein expressed in the yeast was approximately $1.9\%$ of the total soluble protein. Immunoblotting analysis showed the yeast-derived LTB protein was antigenically indistinguishable from bacterial LTB protein. Since the whole-recombinant yeast has been introduced as a new vaccine formulation the expression of LTB in S. cerevisiae can offer an inexpensive yet effective strategy to protect against ETEC, especially in developing countries where it is needed most.

• 미생물학회지
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• 제29권1호
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• pp.16-24
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• 1991

The yeast gene THR1 encodes the homoserine kinase (EC 2.7.1.39: HKase) which catalyses the first step of the threonine specific arm at the end of the common pathway for methionine and threonine biosynthesis. A recombinant plasmid pMC3 (12.6 kilobase pairs, vector YCp50) has been cloned into E. coli HB101 from a yeast genomic library through its complementing activity of a thr1 mutation in a yeast recipient strain M39-1D. When subcloned into pMC32 (8.6kbp, vector YRp7) and pMC35 (8.3 kbp, vector YIp5), the HindIII fragment (2.7 kbp) of pMC3 insery was positive in the thrI complementing activity in both yeast and E. coli auxotrophic strains. The linearized pMC35 was introduced into the original recipient yeast strain and the mitotically stable chromosomal integrant was identified among the transformants. Through the tetrad analysis, the integration site of the pMC35 was localized to the region of THR1 structural gene at an expected genetic distance of approximately 11.1 cM from the ARG4 locus on the right arm of the yeast chromosome VIII. When episomically introduced into the auxotrophic cells and cultured in Thr omission liquid medium, the cloned gene overexpressed the HKase in the order of thirteen to fifteenfold, as compared with a wildtype. HKase levels are repressed by addition of threonine at the amount of 300 mg/l and 1, 190 mg/l for pMC32 and pMC3, respectively. Data from genetic analysis and HKase response thus support that the cloned HindIII yeast DNA fragment contains the yeast thr1 structural gene, along with necessary regulatory components for control of its proper expression.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권1호
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• pp.7-12
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• 2000

The expression of the mouse $\alpha-amylase$ gene in the methylotrophic yeast, P pastoris was investigated. The mouse $\alpha-amylase$ gene was inserted into the multi-cloning site of a Pichi a expression vector, pPIC9, yielding a new expression vector pME624. The plasmid pME624 was digested with SalI or BglII, and was introduced into P. pastoris strain GSl15 by the PEG1000 method. Fifty-three transformants were obtained by the transplacement of pME624 digested with SaiII or BglII into the HIS4locus $(38\;of\;Mut^+\;clone)$ or into the AOX1 locus $(15\;of\;Mut^s\;clone)$. Southern blot was carried out in 11 transformants, which showed that the mouse $\alpha-amylase$ gene was integrated into the Pichia chromosome. When the second screening was performed in shaker culture, transformant G2 showed the highest $\alpha-amylase$ activity, 290 units/ml after 3-day culture, among 53 transformants. When this expression level of the mouse $\alpha-amylase$ gene is compared with that in recombinant Saccharomyces cerevisiae harboring a plasmid encoding the same mouse $\alpha-amylase$ gene, the specific enzyme activity is eight fold higher than that of the recombinant S. cerevisiae.

• 미생물학회지
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• 제28권1호
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• pp.1-5
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• 1990

B형 간염바이러스($\alpha$dr 형)의 내면항원(HBcAg) 유전자는 두개의 단백질 합성시작 유전자 암호 ATG를 갖는다. 하나는 전위내 면항원을 다른 하나는 내면항원 유전자들 위한 ATG 부호이다. 내연항원의 발현과 전위내면항원의 역할을 연구한기 위하여 전위내면 항왼 유전자를 포함하는 것과 포함하지 않는 내연항원 유전자를 효모발현 운반체에 클j료녕 하였다. 또한 내면항원의 발현에 5 upstream 의 역할을 알아보기 위하여 여러 가지의 5’ 제거툴연변이체를 클로닝하였다. 앞에서 만들어진 플라스미드로 여러 효모 균주을 형질전환시킨 후 발헨된 내면항원과 그와 관련된 항원 HBeAg을 방사면역측정법 으로 확인하였다. 효모에서 내면항원 발현의 최적조건 허에서 가장 높은 수준의 항원은 PGK promoter 와 terminator에 내연향원 올 포함한 pGKHBc를 가진 SHY4에서 검출되었다. 전위내면부위의 존재와 우관하게 내면항원은 배양액에서는 검출되지 않고 세포내에서만 검출되었다. 이 결과는 전위내면항원이 효모 내에서 내연항왼의 분비에 영향올 주지않음을 의미한다.

• 미생물학회지
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• 제28권2호
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• pp.114-119
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• 1990

효모 Saccharomyces cerevisiae의 염색체상에 존재하는 superkiller 유전자인 SKIB 유전자를 cloning 시켜 ski 변이 주내에서 발현시켰다. 이 유전자의 C-말단부위에 E. coli의 tacZ 구조 유전자를 융합시켜 효모와 E. coli의 shuttle vector인 pSR605를 제조하고 이를 효모에 형질전환 시킨 후 나타나는 $\beta$-galactosidase의 융합단백질을 확인할 수 있었다.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.206-209
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• 2002

Bacillus stearothermophilus의 CCTase 유전자(cgtS) 대장균과 효모의 shuttle vector로서 항구적 promoter인 adh l promoter를 함유한 pVT103-U(6.9Kb)에 도입하여 재조합 plasmid pVT-CCTS (9.0Kb)을 구축하고 효모 숙주 S. cerevisiae 2805에서 발현시켰다. 재조합 균주의 항구적 발현계인 2805/pv7-CGTS의 최적 발현조건은 YP배지에 dextrose 2%, pH 5.5, 30"C에서 최적 발효조건이었으며, CCTase의 최대 발현량은 48시간 배양시 0.624unit/mL을 나타내었다. B. stearothermophilus의 signal peptide가 재조합 효모에서도 높은 분비효율을 나타내어서 발현된 효소의 87%가 세포 외로 분비 생산되었다.산되었다.

• Journal of Microbiology
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• 제44권6호
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• pp.617-621
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• 2006

Coprinellus congregatus secreted a laccase isozyme when the culture was transferred to an acidic liquid medium (pH 4.1). The laccase cDNA gene (clac2) was used as a probe for cloning of the genomic laccase gene (lac2) including the promoter (Plac2). The open reading frame (ORF) of lac2 had 526 deduced amino acids and four conserved copper binding domains as other fungal laccases. Recombinant plasmid (pRSlac2p-cDNA) of lac2 cDNA with its own promoter was transformed in Saccharomyces cerevisiae. Expression of the transformed lac2 gene was induced by oxidative stress ($H_2O_2$) in yeast and the survival rate of the transformed yeast strain was greatly increased when compared with that of the control strain transformed with pRS316 yeast vector.

• 미생물학회지
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• 제26권1호
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• pp.32-36
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• 1988

The yeast gene HOM3 encodes aspartokinase, which catalyses the first step (aspartate to and from beta-aspartyl phosphate) of common pathway to threonine and methionine. The yeast HOM3 gene expression is known to be regulated by threonine and methionine specific control, and also by general control of amino acid biosynthesis. Isolation and characterization of the HOM3 gene are essential for the molecular genetic study on its regulation of expression. A recombinant plasmid pSC3 (15.5kb, vector YCp50) has been cloned into E. coli HB101 from yeast genomic library through their complementing activity of HOM3 mutation in a yeast recipient strain M34-24B. Organization of the plasmid was characterized by delineation of restriction cleavage sites in the insert fragment.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.61-65
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• 1997

Wild type nodulin 26(nod 26) cDNA(S262) and phodphorylation aite mutant(S262D) were constructed by a yeast expression system using pYES2 plasmids(pTES2-D262 and pTES2-S262D) were sc-reened by restriction mapping with BamHI of KpnI. S262 nod 26 contained a sreine residue at position 262 and S262D nod 26 contained the substitution mutation of serine to aspartic acid residue at position 262 were verified by automated floursent DNA sequencing.

• 한국미생물·생명공학회지
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• 제14권3호
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• pp.213-218
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• 1986

B. amyloliquefaciens의 $\alpha$-amylase 유전자가 S. cerevisiae 내에서 형질발현하는 가를 조사하기 위하여 본, 연구에서 YRp7 plasmid에 B. amyloliquefaciens amylase유전자를 cloning하여 만든 pEA24를 형질전환시켰다. 먼저 YRp7 plasmid를 이용하여 형질전환 최적 조건을 검토하여 본 바, PH 7과 8사이, 반응온도 3$0^{\circ}C$에서 40%의 polyethylene glycol(MW 4,000)을 처리한 후 2 %의 agar를 함유한 재생배지에 중층도말 하였을 때 형질전환율이 가장 높았다. 형질전환주로부터 생성된 amylase의 활성을 측정한 결과, S. cerevisiae에서 약간의 amylase활성을 나타내어 최고 B. amyloliquefaciens의 2% 정도였고, 세포외효소는 검출되지 않았다. 이들 형질전환 주가 가지고 있는 pEA24 plasmid의 안정성을 조사한 결과 YRp7보다 불안정하였으며, 추출한 DNA를 전기영동하여 그 band를 확인하였다.