• Journal of Life Science
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• v.22 no.1
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• pp.7-15
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• 2012

A polyguluronate-specific lyase from Streptomyces sp. strain M3 has been previously cloned and characterized. In this study, the M3 alginate lyase gene in the pColdI vector was mutated by site-directed mutagenesis and random mutagenesis to enhance the alginate degrading activity. Six mutants were obtained: Ser25Arg, Phe99Leu, Asp142Asn, Val163Ala, Lys191Glu, and Gly194Cys. Phe99Leu and Lys191Glu mutants completely lost their alginate lyase activity, whereas the alginate degrading activity of Gly194Cys mutant increased by nearly 10 fold. The 3-D protein structure of M3 alginate lyase, which was constructed using the Swiss-Model automodeler, was also compared to the crystal structure of another alginate lyase. A mutated glycine residue was positioned between Gly193 and Tyr195 of the C-terminal conserved sequence, YFKAGXYXQ. A phenylalanine residue (at position 99) and a glycine residue (at position 194) mutated in this study were distant from the active site, but the degrading activity was strongly affected by their mutation.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.61-67
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• 2011

In 2010, two-spotted spider mite, Tetranychus urticae was collected from the rose greenhouse and apple orchards in Cheongju (CJ), Chungju (CUJ)-1, CUJ-2, Kangjin (KJ), Yesan (YS), and Yeongju (YJ). Among them, KJ and YS strain showed high resistance to bifenazate of 964.5- and 1l30-fold, respectively. The other strains showed low resistance to bifenazate. By analyzing the mitochondrial cytochrome b (cytb) sequence, G126S point mutation was detected in KJ and YS strain. Thus, G126S point mutation in the mitochondrial cytb was available molecular detection marker for selection of bifenazate resistant T. urticae. Two molecular detection methods, quantitative sequencing (QS) and PCR amplification of specific alleles (PASA) were well detected specific G126S point mutation. Therefore, these methods can be used to monitor the resistance allele in field population of T. urticae and bifenazate resistance management strategy.

• Journal of KIISE:Software and Applications
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• v.27 no.11
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• pp.1115-1122
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• 2000

기존의 블록 정합 알고리즘인 FS(Full Search) 알고리즘은 정확한 움직임 벡터를 구할 수 있으나 요구되는 계산량이 많다. 반면에 국부 탐색을 하는 고속 블록 정합 알고리즘은 FS보다 빠른 탐색을 할 수 있으나 FS 보다 정합 오차가 크다. 본 연구는 전역탐색을 하는 유전자 알고리즘에 빠른 탐색을 하는 블록 정합 알고리즘인 NTSS(New Three Ste Search)알고리즘을 제안한다. 제안한 방법에서 각 염색체는 움직임 벡터를 표현하며 초기 염색체는 탐색 공간의 중심 탐색점 가까이에 고정적으로 발생시키고 각 염색체는 MSE(Mean Square Error)값으로 평가된다. 평가된 염색체 중 작은 MSE값을 가지는 염색체가 NTSS의 탐색점 수만큼 다음 세대의 탐색점으로 선택된다. 선택된 염색체는 세대를 거치면서 돌연변이 연산과 교배연산이 행해지고 이 때 돌연변이 연산의 크기는 NTSS의 탐색 단계 크기가 된다. 제안한 세대 수 만큼 반복 후 최소의 MSE 값을 가지는 유전자가 해당 블록의 움직임 벡터가 된다. 시뮬레이션 결과 제안한 방법을 가장 우수한 성능을 가지는 FS와 유사한 MSE 값을 얻을 수 있었고 동시에 FS에서 요구되는 계산량에 비해 많은 계산량을 줄일 수 있었다.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2000.11a
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• pp.12-12
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• 2000

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.93-104
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• 2023

This study aimed to identify new markers that cause lung adenocarcinoma by analyzing mutation hotspots for the top five genes with high mutation frequency in lung adenocarcinoma in Koreans by next generation sequencing (NGS) analysis. The association between TP53 mutation types and patterns with smoking, a major cause of lung cancer, was examined. The clinicopathological characteristics of lung adenocarcinoma patients with TP53 P72R SNPs were analyzed. In Korean lung adenocarcinoma cases, regardless of the smoking status, the TP53 P72R SNP was the most frequently occurring mutational hotspot, in which the nucleotide base was transversed from C to G, and the amino acid was substituted from proline to arginine at codon 72 of TP53. An analysis of the clinicopathological characteristics of lung adenocarcinoma cases with TP53 P72R SNP revealed no significant correlation with the patient's age, gender, smoking status, and tumor differentiation, but a significant correlation with low stage (P-value =0.026). This study confirmed an increase in TP53 rather than EGFR, which was reported as the most frequent mutations in lung adenocarcinoma in Koreans through NGS. Among them, TP53 P72R SNP is the most frequent regardless of smoking status.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.43-54
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• 2004

This study analyzes characteristics and applicability of genetic algorithms and genetic operators to optimize highway alignments. Genetic algorithms, one of artificial intelligence techniques, are fast and efficient search algorithms for generating, evaluation and finding optimal highway alignment alternatives. The performance of genetic algorithms as an optimal search tool highly depends on genetic operators that are designed as a problem-specific. This study adopts low mutation operators(uniform mutation operator, straight mutation operator, non-uniform mutation operator whole non-uniform mutation operator) to explore whole search spaces, and four crossover operators(simple crossover operator, two-point crossover operator, arithmetic crossover operator, heuristic crossover operator) to exploit food characteristics of the best chromosome in previous generations. A case study and a sensitivity analysis have shown that the eight problem-specific operators developed for optimizing highway alignments enhance the search performance of genetic algorithms, and find good solutions(highway alignment alternatives). It has been also found that a mixed and well-combined use of mutation and crossover operators is very important to balance between pre-matured solutions when employing more crossover operators and more computation time when adopting more mutation operators.

• The Microorganisms and Industry
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• v.11 no.1
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• pp.13-20
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• 1985

특이 단백질(gene II protein)의 정성적 또는 정량적 변화에 의해 DNA 복제에 필요한 replication orgin sequence의 일부분이었단 replication enhancer를 불필요하게 함으로써 minimum replication origin을 core region만으로 국한 되게 함이었다.

• Journal of Life Science
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• v.14 no.2
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• pp.296-300
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• 2004

We investigated feasibility of using the formalin-fixed and paraffin-embedded tissue to study mitochondrial mutations in the case that fresh or frozen tissue, or blood samples are not available. Four paraffin blocks of muscle biopsies in Korean MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) patients were chosen. Total DNA was extracted from these blocks for PCR/RFLP analysis, and sequencing was performed to study the most common mutation, A to G transition at nucleotide position 3243 underlying MELAS in the mitochondrial tRN $A^{Leu(UUR)}$ gene. We could identify the A to G mutation at nt.3243 in three MELAS patients. Our results show that the mitochondrial genome of our paraffin blocks is presumably in good condition. Our results are in accordance with the previous findings by other investigators that PCR allows molecular genetic analysis of paraffin-embedded tissues stored in most histopathology laboratories.s.

• Korean Journal of Animal Reproduction
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• v.18 no.3
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• pp.191-197
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• 1994

It is generally known that mutations in any of several genes encoding photoreceptor-specific proteins have resulted in retinitis pigmentosa (RP), a disease characterized by losing photoreceptor function with progressive degeneration of photoreceptor cells and eventually leading to blindness. To study the procure and cure of photoreceptor degeneration, we produced transgenic mice. Transgene consisted of a 12.5kb genomic DNA fragment that contains mutated pig rhodopsin gene (Pro-347-Ser) including both the 5'-franking (4.0 kb) and the 3'-franking (2.9 kb) sequences. This gene was used for the production of transgenic mouse. The mutated rhodopsin DNA was microinjected into male pronuclei of fertilized mouse (C57BL /6]) embryos. We detected transgenic animals harboring mutated rhodopsin gene by PCR and Southern blot analysis. These transgenic mice showed stable transmission of microinjected rhodopsin gene into their offspring. Therefore these animals will provide a novel approach to study the mechanism of the photoreceptor degeneration and be provided as a disease model for the treatment of the blind in human.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.4
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• pp.143-151
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• 2000

Purpose : The p53 tumor suppressor gene is one of the most frequently altered genes in human malignancies. We try to explore the implication of p53 alteration in Ewing's sarcoma. Materials and Methods : We analyzed 35 paraffin blocks to explore the deletion and sequence alterations of p53. Results : Quantitative PCR analysis showed that 2 tumors showed a homozygous deletion of the gene. Mutational analysis of exons 4 to 9 of p53 by PCR-SSCP revealed that 3 tumors carry sequence alterations in exons 5 or 8, and DNA sequencing analysis identified missense point mutations. Conclusion : Taken together, our data demonstrate that p53 is genetically altered in a small fraction of Ewing's sarcoma.