• 한국미생물·생명공학회지
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• 제35권3호
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• pp.177-183
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• 2007

열충격 시그마인자를 코딩하는 유전자 rpoH가 결여된 돌연변이체 대장균(Escherichia coli satrain A7448)을, 메탄올 자화세균인 Methylovorus sp. strain SS1 DSM11726의 phagemid library로 형질전환 시켜서 $30^{\circ}C$에서 성장하는 Escherichia coli strain A7448 로부터 Methylovorus sp. strain SS1 DSM11726의 rpoH 유전자를 클로닝하고 그 염기서열을 분석하였다. 1,793-bp 염기서열 분석 결과 Methylovorus sp. strain SS1 DSM11726의 RpoH는 284개의 아미노산으로 이루어져 있었으며 예상된 분자량은 32,006, p1값은 5.79로 나타났으며, 동일계열의 ${\beta}$-proteobacteria에 속하는 세균들의 RpoH와 높은 상동성을 보여주었다. Methylovorus sp. strain SS1 DSM11726의 RpoH는 대장균의 RpoH의 기능을 대신할 수 있음을 보여주었다. 열충격 후 RpoH양은 15분까지 지속적으로 증가하다 20분 뒤 양이 감소하는 양상을 나타내었다. 이는 Methylovorus sp. strain SS1 DSM11726의 RpoH 단백질 역시 열에 의해 유도됨을 말해 준다.

• Mycobiology
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• 제38권2호
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• pp.102-107
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• 2010

We identified a gene for $\beta$-1,3-glucan synthesis (GBG1), a nonessential gene whose disruption alters cell wall synthesis enzyme activities and cell wall composition. This gene was cloned by functional complementation of defects in $\beta$-1,3-glucan synthase activity of the the previously isolated Saccharomyces cerevisiae mutant LP0353, which displays a number of cell wall defects at restrictive temperature. Disruption of the GBG1 gene did not affect cell viability or growth rate, but did cause alterations in cell wall synthesis enzyme activities: reduction of $\beta$-1,3-glucan synthase and chitin synthase III activities as well as increased chitin synthase I and II activities. GBG1 disruption also showed altered cell wall composition as well as susceptibility toward cell wall inhibitors such as Zymolyase, Calcofluor white, and Nikkomycin Z. These results indicate that GBG1 plays a role in cell wall biogenesis in S. cerevisiae.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.408-411
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• 2009

In this paper, conventional PI, fuzzy neural network(FNN) and adaptive teaming mechanism(ALM)-FNN for rotor field oriented controlled(RFOC) induction motor are studied comparatively. The widely used control theory based design of PI family controllers fails to perform satisfactorily under parameter variation nonlinear or load disturbance. In high performance applications, it is useful to automatically extract the complex relation that represent the drive behaviour. The use of learning through example algorithms can be a powerful tool for automatic modelling variable speed drives. They can automatically extract a functional relationship representative of the drive behavior. These methods present some advantages over the classical ones since they do not rely on the precise knowledge of mathematical models and parameters. Comparative study of PI, FNN and ALM-FNN are carried out from various aspects which is dynamic performance, steady-state accuracy, parameter robustness and complementation etc. To have a clear view of the three techniques, a RFOC system based on a three level neutral point clamped inverter-fed induction motor drive is established in this paper. Each of the three control technique: PI, FNN and ALM-FNN, are used in the outer loops for rotor speed. The merit and drawbacks of each method are summarized in the conclusion part, which may a guideline for industry application.

• 한국균학회지
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• 제38권1호
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• pp.29-33
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• 2010

KGD1 유전자는 비허용온도에서 세포벽에 결함을 보이는 Saccharomyces cerevisiae LP0353 균주의 베타-1,3-글루칸 합성 효소의 활성을 회복시키는 유전자로 분리되었다. $\alpha$-ketoglutarate dehydrogenase를 암호화하는 KGD1 유전자의 효모의 세포벽 합성과 연관된 기능을 분석하기 위하여 유전자 파괴를 시도하였다. KGD1돌연변이는 생장속도가 감소하고, 키틴 합성 효소들의 활성이 증가하였으며, 세포벽 구성 당류의 함량에 변화를 보였다. 또한 Calcofluor white과 Nikkomycin Z 등과 같은 세포벽 합성 저해물질에 대해 감수성 변화를 나타냈다. 이러한 결과들은 KGD1이 효모의 세포벽 특히 베타-1,6-글루칸과 키틴의 생합성에 영향을 주고 있음을 시사한다.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.633-643
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• 2017

To examine the pro-apoptotic role of the human ortholog (YPEL5) of the Drosophila Yippee protein, the cell viability of Saccharomyces cerevisiae mutant strain with deleted MOH1, the yeast ortholog, was compared with that of the wild-type (WT)-MOH1 strain after exposure to different apoptogenic stimulants, including UV irradiation, methyl methanesulfonate (MMS), camptothecin (CPT), heat shock, and hyperosmotic shock. The $moh1{\Delta}$ mutant exhibited enhanced cell viability compared with the WT-MOH1 strain when treated with lethal UV irradiation, 1.8 mM MMS, $100{\mu}M$ CPT, heat shock at $50^{\circ}C$, or 1.2 M KCl. At the same time, the level of Moh1 protein was commonly up-regulated in the WT-MOH1 strain as was that of Ynk1 protein, which is known as a marker for DNA damage. Although the enhanced UV resistance of the $moh1{\Delta}$ mutant largely disappeared following transformation with the yeast MOH1 gene or one of the human YPEL1-YPEL5 genes, the transformant bearing pYES2-YPEL5 was more sensitive to lethal UV irradiation and its UV sensitivity was similar to that of the WT-MOH1 strain. Under these conditions, the UV irradiation-induced apoptotic events, such as FITC-Annexin V stainability, mitochondrial membrane potential (${\Delta}{\psi}m$) loss, and metacaspase activation, occurred to a much lesser extent in the $moh1{\Delta}$ mutant compared with the WT-MOH1 strain and the mutant strain bearing pYES2-MOH1 or pYES2-YPEL5. These results demonstrate the functional conservation between yeast Moh1 and human YPEL5, and their involvement in mitochondria-dependent apoptosis induced by DNA damage.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1500-1508
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• 2013

Ebosin, a novel exopolysaccharide produced by Streptomyces sp. 139, has obvious antirheumatic arthritis activity in vivo, and its biosynthesis gene cluster (ste), consisting of 27 open reading frames, has been identified. This paper reports our study of the gene functionality of ste8, the predicted protein product of which is homologous to some bacterial chain length determinant Wzz proteins. For characterization of Ste8, ste8 was cloned and expressed in the mutant strain E. coli 086:H2 (${\Delta}wzz$). The functional complementation of wzz by ste8 was demonstrated by the restoration of wild-type lipopolysaccharide biosynthesis and increased levels of serum resistance of E. coli 086:H2 (${\Delta}wzz$) (pET30a-ste8). To examine the function of ste8 in ebosin biosynthesis, the gene was knocked out with a double crossover via homologous recombination. The molecular weight of the ebosin derivative EPS-8m produced by the mutant Streptomyces sp. 139 ($ste8^-$) was much lower than that of ebosin, and the binding activity of EPS-8m for IL-1R decreased significantly compared with ebosin. These results demonstrate that ste8 encodes a chain length determinant (Wzz) that functions in ebosin biosynthesis.

• 생명과학회지
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• 제14권6호
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• pp.1023-1027
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• 2004

본 연구는 출아형 효모 Saccharomyces cerevisiae에서 자외선의 상해 시 이를 정상으로 회복시키는 절제회복(excision repair) 유전자로 알려진 RADS의 특성 규명을 위하여 균류 Coprinus cinereus에서 이와 유사한 유전자를 분리하였다. RADS 유사 유전자를 분리하기 위하여 균류 C. cinereus의 염색체 DNA를 전기영동하여 분리한 다음 효모 RADS DNA를 probe로 하여 이와 hybridization하였다. 이 결과 RADS유사 유전자는 3.4kb의 insert DNA를 갖고 있었다. 또한 Southern hybridization으로 이 유사 유전자는 fungus C. cinereus의 염색체에 존재함을 확인하였다. 분리한 RADS 유사 유전자의 전사체 크기는 2.8kb 였으며, 자외선의 상해시 전혀 자외선에 대한 유도성이 없음을 Northern hybridization으로 확인하였다. 또한 유사유전자 부분을 삭제하였을 때 이 부분이 없는 세포는 전혀 생존을 못하였다. 이 결과 분리한 RADS 유사유전자는 세포의 생존에 필수적인 유전자임을 알 수 있었다.

• Molecules and Cells
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• 제39권8호
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• pp.594-602
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• 2016

Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of $Ser^{78}$ to $Cys^{78}$ resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of $Cys^{78}$ in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced1 survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone.

• BMB Reports
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• 제41권2호
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• pp.112-118
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• 2008

Camptothecin is an anti-cancer monoterpene indole alkaloid. The gene encoding 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (designated as CaHDR), the last catalytic enzyme of the MEP pathway for terpenoid biosynthesis, was isolated from camptothecin-producing Camptotheca acuminata. The full-length cDNA of CaHDR was 1686 bp encoding 459 amino acids. Comparison of the cDNA and genomic DNA of CaHDR revealed that there was no intron in genomic CaHDR. Southern blot analysis indicated that CaHDR belonged to a low-copy gene family. RT-PCR analysis revealed that CaHDR expressed constitutively in all tested plant organs with the highest expression level in flowers, and the expression of CaHDR could be induced by 100 ${\mu}M$ methyl-jasmonate (MeJA), but not by 100 mg/L salicylic acid (SA) in the callus of C. acuminata. The complementation of CaHDR in Escherichia coli ispH mutant MG1655 demonstrated its function.

• 한국균학회지
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• 제36권2호
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• pp.189-195
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• 2008

Aspergillus nidulans는 빛이 없는 조건에서는 유성분화가 주로 일어나고 빛이 있는 조건에서는 유성분화가 억제되고 대신 무성분화가 유도된다. 빛에 의해서 유성분화가 억제되는 것은 빛에 반응하여 유성 또는 무성분화를 조절하는 유전자가 있다는 것을 시사한다. 따라서 빛에 의해서 조절되는 유전자를 연구하기 위하여 광 조건하에서 유성분화를 하는 silA98 돌연변이를 분리하였으며, 이를 보완하는 유전자를 분리 및 분석하고자 A. nidulans의 AMA-NotI genomic library로부터 silA98 돌연변이를 상보하는 유전자 silA를 분리하였다. silA 유전자의 예상 ORF는 2,388 bp의 염기로 구성되어지고 795개의 아미노산을 암호화하고 있었다. 이 유전자는 Saccharomyces cerevisiae의 ARO80 유전자와 상동성을 보이며 SilA 단백질의 N 말단에는 약 51.9%의 상동성을 가지는 ${Zn_2}{Cys_6}$ motif를 지니고 있었다. silA 유전자 결손돌연변이주는 광 존재 하에서뿐만 아니라 고농도의 sorbitol에서도 유성분화가 유도되었다. 이는 silA 유전자가 빛과 고삼투 조건에서 유성분화를 억제하는 조절과정에 관여하고 있음을 의미한다. silA 유전자를 niiA promoter로 과다 발현시켰을 때의 형질은 야생형과 큰 차이를 보이지 않았다.