• 한국미생물·생명공학회지
• /
• 제17권4호
• /
• pp.295-300
• /
• 1989

B. thuringiensis가 생산하는 살충성 독소 단백질의 생태학적 응용방법을 개발하기 위한 목적으로 우선 독소 단백질 유전자를 옮겨 발현시키기에 적합한 숙주 미생물의 분리작업을 수행하였다. 국내 주요농산물인 고추, 감자, 무우 등 7가지 농작물의 뿌리부근에 군락을 형성하는 35종의 형광성Pseudomonas들을 분리하였고 독소 단백질 유전자를 함유하는 재조합 plasmid에 대한 숙주로서의 이응가능성을 검토해 보기 위하여 분리균주 35주에 대한 형질전환을 실시한 결과 4주에 독소 단백질 유전자의 도입이 가능하였고 생물검정과 면역학적인 방법 등에 의한 결과 BT 독소 유전자의 발현을 확인하였다.

• Journal of Microbiology and Biotechnology
• /
• 제12권5호
• /
• pp.826-828
• /
• 2002

In our previous studies, we have cloned and characterized a gene region from Bradyrhizobium japonicum ,which is involved in the synthesis of lipopolysaccharide (LPS). In this study, we have expanded the sequence analysis of the region and found an additional open reading frame (orf), which appeared to be divergently transcribed from the rfaF gene. Sequence alignment of the orf revealed a significant similarity with rfaD genes of Salmonella typhimurium , Escherichia coli, and Neisseria gonorrhoeae. These genes encode a heptose-6-epimerase, which catalyzes the interconversion of ADP -D -glycerol-D-manno-heptose to ADP-L-glycero-D-manno-heptose. This divergent organization of the rfaF and rfaD genes is different from that of other Gram-negative bacteria where two genes form an operon. A rfaD- mutant of E. coli was successfully transformed with plasmid constructs containing the rfaD gene of B. japonicum. Novobiocin sensitivity test showed that the rfaD gene from B. japonicum could complement the rfaD mutation in E. coli, which confirms the functionality of the cloned B. japonicum gene.

• Journal of Microbiology and Biotechnology
• /
• 제3권4호
• /
• pp.224-231
• /
• 1993

The nucleotide sequence of the xylanase gene (xynY) from alkalophilic Bacillus sp. YC-335 was determined and analyzed. An open reading frame of 1, 062 base pairs for xynY gene was observed and encoded for a protein of 354 amino acids with a molecular weight of 38, 915. S1 nuclease mapping showed that the transcription initiation sites of the xynY gene were different in Bacillus sp. YC-335 and Escherichia coli HB101 (pYS55). S1 mapping also showed that -10 region of the xynY gene recognized by RNA polymerases of E. coli and Bacillus sp. YC-335 were TACAGT and TATGAT , respectively. A ribosome binding site sequence with the free energy of -17.0 Kcal/mol was observed 9 base pairs upstream from the unusual initiation codon, TTG. The proposed signal sequence consisted of 27 amino acids, 2 of which were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YC-335 xylanase showed more than 50% homology with xylanases from B. pumilus, B. subtilis, and B. circulans.

• Journal of Microbiology and Biotechnology
• /
• 제22권6호
• /
• pp.793-799
• /
• 2012

A gene related to high pristinamycin yield in Streptomyces pristinaespiralis was selected by amplified fragment length polymorphism (AFLP) and its functions were investigated by gene disruption. First, a 561 bp polymorphic sequence was acquired by AFLP from high-yield recombinants compared with the S. pristinaespiralis ancestor ATCC25486, indicating that this approach is an effective means of screening for valuable genes responsible for antibiotic yield. Then, a 2,127 bp open reading frame of a gene designated spy1 that overlaps with the above fragment was identified and its structure and biological functions were investigated. In silico analysis of spy1 encoding a deduced 708-amino-acid-long serine/threonine protein kinase showed that it only contains a catalytic domain in the N-terminal region, which is different from some known homologs. Gene inactivation of chromosomal spy1 indicated that it plays a pleiotropic regulatory function in pristinamycin production, with a positive correlation to pristinamycin I biosynthesis and a negative correlation to pristinamycin II biosynthesis.

• 한국생물정보학회:학술대회논문집
• /
• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
• /
• pp.63-68
• /
• 2005

Transcription factors regulate gene expression by binding to gene upstream region. Each transcription factor has the specific binding site in promoter region. So the analysis of gene upstream sequence is necessary for understanding regulatory mechanism of genes, under a plausible idea that assumption that DNA sequence motif profiles are closely related to gene expression behaviors of the corresponding genes. Here, we present an effective approach to the analysis of the relation between gene expression profiles and gene upstream sequences on the basis of kernel canonical correlation analysis (kernel CCA). Kernel CCA is a useful method for finding relationships underlying between two different data sets. In the application to a yeast cell cycle data set, it is shown that gene upstream sequence profile is closely related to gene expression patterns in terms of canonical correlation scores. By the further analysis of the contributing values or weights of sequence motifs in the construction of a pair of sequence motif profiles and expression profiles, we show that the proposed method can identify significant DNA sequence motifs involved with some specific gene expression patterns, including some well known motifs and those putative, in the process of the yeast cell cycle.

• 한국지능시스템학회논문지
• /
• 제17권5호
• /
• pp.707-711
• /
• 2007

Microarray gene expression data is believed to show the functions of living organism through the gene expression values. We have studied a method to get the informative genes from the microarray gene expression data. There are several ways for this. In recent researches to get more sophisticated and detailed results, it has used the intelligence information theory like fuzzy theory. Some methods are to add fudge factors to the significance test for more refined results. In this paper, we suggest a method to get informative genes from microarray gene expression data. We combined the difference of means between two groups and the fuzzy membership degree which reflects the variance of the gene expression data. We have called our significance test the Fuzzy Information method for Gene Expression data(FIGER). The FIGER calculates FIGER variation ratio and FIGER membership degree to show how strongly each object belongs to the each group and then it results in the significance degree of each gene. The FIGER is focused on the variation and distribution of the data set to adjust the significance level. Out simulation shows that the FIGER-test is an effective and useful significance test.

• Journal of Microbiology and Biotechnology
• /
• 제18권2호
• /
• pp.334-337
• /
• 2008

A tightly regulated gene expression system composed of a single-copy target gene under the control of a lac promoter derivative and lacI gene in a multicopy plasmid is proposed, and its ability to control the flux of a metabolic pathway is demonstrated. A model system to control the flux of acetyl-CoA to acetyl phosphate was constructed by integrating pta, a gene encoding phosphotransacetylase, under a tac promoter into the chromosome of E. coli with a pta-negative background and transforming a multicopy plasmid containing the $lacI^Q$ gene into the strain. The production rate of acetate was shown to be tightly controlled when varying the concentration of the inducer (IPTG) in he model system.

• BMB Reports
• /
• 제32권1호
• /
• pp.72-75
• /
• 1999

In an effort to understand the function of the eryBVII gene in the erythromycin biosynthetic gene cluster, we overexpressed the eryBVII gene in E. coli and TDP-6-deoxy-L-threo-D-glycero-4-hexulose was used as a substrate of the overexpressed EryBVII enzyme. The enzymatic reaction product was chemically modified by reduction and peracetylation. Structural analysis of the derivatized enzymatic products by GC-Mass Spectrophotometry indicated that TDP-6-deoxy-L-threo-D-glycero-4-hexulose could be converted into its epimer by EryBVII enzyme. Based on this result, TDP-6-deoxy-L-threo-D-glycero-4-hexulose was indeed the substrate of EryBVII enzyme and the function of the eryBVII gene was confirmed.

• Korean Chemical Engineering Research
• /
• 제47권5호
• /
• pp.538-545
• /
• 2009

본 총설에서는 주사형프로브현미경의 원리와 응용에 관하여 간략히 설명하고 최근 본 그룹에 의하여 활발하게 연구되고 있는 나노탐침과 AFM(원자간력현미경 atomic force microscopy)을 이용한 저침습성(low-invasive) 단일세포 조작기술과 고효율 유전자 도입기술을 소개하고자 한다. 시판 AFM 탐침을 침상구조로 가공한 나노탐침과 AFM을 이용하였을 경우, 탐침의 세포삽입의 성공여부를 force-distance curve 상의 척력소실의 유무로 판단할 수 있다. 침상 나노탐침을 사용하면 대부분의 세포에서 80~90%의 고효율 세포삽입이 가능하여 마이크로인젝션용 미세관을 이용하는 경우보다 세포삽입효율이 높았다. 또한 나노탐침의 직경이 400 nm 이하의 경우에는 세포 종류에 관계없이 장시간 나노탐침의 삽입에도 세포활성에 큰 영향이 없었다. 침상나노탐침을 이용하여 DNA를 도입하였을 경우에도 기존의 DNA 도입방법과 비교하여 높은 도입효율과 유전자 발현율로 DNA를 도입할 수 있는 가능성을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권9호
• /
• pp.1349-1353
• /
• 2007

Calcineurin is a calmodulin dependent protein that functions as a regulator of muscle cell growth and function. Agents capable of interacting with calcineurin could have important applications in muscle disease treatment as well as in the improvement of livestock production. Calsarcins comprise a family of muscle-specific calcineurin binding proteins which play an important role in modulating the function of calcineurin in muscle cells. Recently, we described the first two members of the calsarcin family (calsarcin-1 and calsarcin-2) in the pig. Here, we characterized the third member of the calsarcin family, calsarcin-3, which is also expressed specifically in skeletal muscle. However, unlike calsarcin-1 and calsarcin-2, the calsarcin-3 mRNA expression in skeletal muscle kept rising throughout the prenatal and postnatal development periods. In addition, radiation hybrid mapping indicated that porcine calsarcin-3 mapped to the distal end of the q arm of pig chromosome 2 (SSC2). A C/T single nucleotide polymorphism site in exon 5 was genotyped using the denaturing high performance liquid chromatography (DHPLC) method and the allele frequencies at this locus were significantly different among breeds.