• BMB Reports
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• v.34 no.4
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• pp.342-346
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• 2001

The Mycobacterium bovis BCG panB gene, encoding ketopantoate hydroxymethyltransferase (KPHMT), was cloned from a ${\lambda}gt11$ genomic library and sequenced. The DNA sequence encodes a protein that contains 281 amino acid residues (M, 29,337) with a high similarity to the KPHMTs. Subcloning of a 846 by open reading frame (ORF), but not a 735 by ORF, into the vector pUC19 led to complementation of the panB mutant of Escherichia coli. The BCG pang gene was overexpressed in E. coli and the KPHMT purified to homogeneity The recombinant protein was further confirmed by an enzymatic assay.

• BMB Reports
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• v.44 no.12
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• pp.805-810
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• 2011

Methionine sulfoxide reductase A (MSRA) is a ubiquitous enzyme that has been demonstrated to reduce the S enantiomer of methionine sulfoxide (MetSO) to methionine (Met) and can protect cells against oxidative damage. In this study, we isolated a novel MSRA (SlMSRA2) from Micro-Tom (Solanum lycopersicum L. cv. Micro-Tom) and characterized it by subcloning the coding sequence into a pET expression system. Purified recombinant protein was assayed by HPLC after expression and refolding. This analysis revealed the absolute specificity for methionine-S-sulfoxide and the enzyme was able to convert both free and protein-bound MetSO to Met in the presence of DTT. In addition, the optimal pH, appropriate temperature, and $K_m$ and $K_{cat}$ values for MSRA2 were observed as 8.5, $25^{\circ}C$, $352{\pm}25\;{\mu}M$, and $0.066{\pm}0.009\;S^{-1}$, respectively. Disk inhibition and growth rate assays indicated that SlMSRA2 may play an essential function in protecting E. coli against oxidative damage.

• Journal of Plant Biology
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• v.38 no.1
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• pp.107-113
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• 1995

pRLYS1 containing intact rbcL gene of maize (Zea mays L. cv Golden X Bantam T-51; Zm-A) was digested with several restriction enzymes to construct subcones carrying promoter region of rbcL. The DNA fragments of 0.20, 0.19, 0.92 and 1.55 kb among the EcoRI digests, the EcoRI-DdeI digests, the AvaI digests and the EcoRI-BamHI digests of pRLYS1 were subcloned into pBluscriptSK＋and named pRLPS2, pRLPS3, pRLPS14 and pRLPS35, respectively. Four subclones contain the 1.92 kb portion from 136 nucleotide downstream to 1780 nucleotide upstream from the ATG initiation codon of rbcL gene. pRLPS2 (-29 to -229) and pRLPS3 (-239 to -420 from the ATG) were sequenced. When nucleotide sequence of Zm-A was compared with sequence of rbcL promoter region of a different cultivar of maize (Zea mays L. cv WFG TMS X BS7; Zm-B), the difference rate between two cultivars was 4.3%. The mean of sequence divergence between Zm-A and three grass species in the same tribe, Andropogoneae, in the upstream region from 29 to 420 of ATG was 1.8%, whereas between Zm-B and above-mentioned three species was 5.4%. Therefore, Zm-A seems to evolutionarily closer to three other species in Andropogoneae tribe than Zm-B is.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.574-580
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• 2007

Full-length chloride intracellular channel protein 1 (CLIC1) is a member of the family of proteins related to bovine chloride intracellular channel p64. Mutations in the SEDL gene cause spondyloepiphyseal dysplasia tarda (SEDT), a rare X-linked chondrodysplasia. The link between the intracellular chloride channels and SEDL is an important step toward understanding their functional interplay. In the present study, CLIC1 protein was subcloned into the pGEX-KG vector and overexpressed in XL-1 blue cells. We developed a large-scale expression system composed of glutathione S-transferase (GST) fused with a 240-amino-acid CLIC1 protein in Escherichia coli. The soluble CLIC1 protein was successfully purified to homogeneity, and its purity, identity, activity and conformation were determined using SDS-PAGE, MALDI-MS, biophotometer and circular dichroism spectroscopic studies. The binding of both CLIC1 and SEDL proteins in vitro was detected by BIAcore biosensor and fluorescence measurements.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.48-53
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• 1993

For the purpose to improve the glucoamylase productivity of Saccharomyces diastaticus, we integrated STA 1 gene into chromosomal DNA of S. diastaticus using YIp vector. After construction of Ylp-STA by the subcloning of STAI (5.3 kb) into YIp5 vector, S. diastaticus GMT-II(a. ura3. STAJ) was transformed by Ylp-STA through homologous recombination at the chromosomal STAJ gene. So we obtained the tram formants that glucoamylase productivity was increased maximum six fold. These strains transformed by the multi-copy integration of Ylp-STA in chromosomal DNA were confirmed by Southern hybridization. And the integrated Ylp-STA was maintained stably during 30 mitotic divisions.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.447-452
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• 2014

To isolate novel and useful microbial enzymes from uncultured gastrointestinal microorganisms, a fecal microbial metagenomic library of the pygmy loris was constructed. The library was screened for amylolytic activity, and 8 of 50,000 recombinant clones showed amylolytic activity. Subcloning and sequence analysis of a positive clone led to the identification a novel gene (amyPL) coding for ${\alpha}$-amylase. AmyPL was expressed in Escherichia coli BL21 (DE3) and the purified AmyPL was enzymatically characterized. This study is the first to report the molecular and biochemical characterization of a novel ${\alpha}$-amylase from a gastrointestinal metagenomic library.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.132-137
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• 1997

A novel protein (HEAAE, High Essential Amino Acid Encoding Protein), rich in essential amino acids ($75{\%}$ of total), was designed and constructed in our laboratory. The designed peptides were analyzed by SYBLE and stable secondary and tertiary structures were predicted. The monomeric form (HEAAE-1) of the protein consists of 20 amino acid residues with four additional amino acids comprising a potential ${\beta}$-turn (HEAAE-4). Size exclusion analysis demonstrated that the monomer is self-aggregates in aqueous solution to form higher ordered multimeric structures, which are very reminiscent of natural plant storage proteins. The DNA encoding this amino acid sequence was synthesized, and from this monomeric gene fragment (heaae-1), the stable tetrameric form of the gene (heaae-4) was generated by subcloning into the E. coli expression vector pKK223-3. A clear 6 kDa polypeptide band corresponding to the molecular weight of the dimeric form (HEAAE-2) was detected. The smeared band which appeared around the molecular weight corresponding to HEAAE-4 of 11 kDa suggested that the tetramer form of this protein might be processed into smaller size products.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.639-647
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• 2008

The heat-inducible expression vectors for Corynebacterium glutamicum and C. ammoniagenes were constructed by using the ${\lambda}O_L1$ and the cryptic promoters, CJ1 and CJ4 that express genes constitutively in C. ammoniagenes. Although the promoters were isolated from C. ammoniagenes, CJ1 and CJ4 were also active in C. glutamicum. To construct vectors, the $O_L1$ from the ${\lambda}P_L$ promoter was isolated and fused to the CJ1 and CJ4 promoters by recombinant PCR. The resulting artificial promoters, CJ1O and CJ4O, which have one ${\lambda}O_L1$, and CJ1OX2, which has two successive ${\lambda}O_L1$, were fused to the green fluorescent protein (GFP) gene followed by subcloning into pCES208. The expression of GFP in the corynebacteria harboring the vectors was regulated successfully by the temperature-sensitive cI857 repressor. Among them, C. ammoniagenes harboring plasmid pCJ1OX2G containing GFP fused to CJ1OX2 showed more GFP than the other ones and the expression was tightly regulated by the repressor. To construct the generally applicable expression vector using the plasmid pCJ1OX2G, the His-tag, enterokinase (EK) moiety, and the MCS were inserted in front of the GFP gene. Using the vector, the expression of pyrR from C. glutamicum was tried by temperature shift-up. The results indicated that the constructed vectors (pCeHEMG) can be successfully used in the expression and regulation of foreign genes in corynebacteria.

• Journal of Life Science
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• v.14 no.3
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• pp.391-395
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• 2004

To overproduce the cyclodextrin glucanotransferase(CGTase) of Bacillus stearothermophilus NO2 in B. subtilis, the pJH-CGTl plasmid (8.14 kb) was constructed, in which the ORF of CGTase gene could be transcribed by strong constitutive promoter, P$\_$JH/. To overproduce CGTase from a recombinant B. subtilis, the effect of media on the cell growth and expression level of CGTase were investigated with various media (LB, 2${\times}$LB, 5% molasses+2% CSL, CS, LBG) in the flask culture. Among them, [5% molasses+2% CSL] medium revealed the maximum expression level of CGTase with 1.8 unit/$m\ell$ at 9 hr culture. In the batch culture on [10% molasses+5% corn steep liquor] medium the expression level of CGTase, the secretion efficiency, and plasmid stability were about 4.2 unit/$m\ell$, 90% and 90%, respectively, at 30 hr culture. The cell growth and expression level in the fermenter culture with the industrial molasses medium were increased by 2-folds over the flask culture.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.93-97
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• 1997

For the molecular genetic study of cold tolerance mechanism in plants, a cDNA encoding fatty acid desaturase (fad3), converting linoleic acid (18:2, $\omega$-6) to linolenic acid (18:3, $\omega$-3), was isolated from $\lambda$ZAPII Arabidopsis thaliana cDNA expression library by plaque hybridization using fad3 cDNA probe derived from Brassica napus. A 1.8 kb-EcoRI fragment from a lambda clone showing a strong positive hybridization signal was subcloned into pGEM7 and analyzed for its nucleotide sequence. From deduced amino acid sequences, the fad3 gene was revealed to have an open reading frame(ORF) consisting of 386 amino acids with a molecular mass of 44,075 Da. The fad3 gene was compared to chloroplast $\omega$-3 fatty acid desaturase (fad7) and endoplasmic reticulum Δ12 fatty acid desaturase (fad2) to show 70% and 58% amino acid sequence homology, respectively, Especially, amino acids of internal (82 to 151) and carboxy terminal (276 to 333) regions were highly conserved, implying their requisite role for enzymatic functioning of fatty acid desaturases. IPTG-induced fad3 cDNA expression in E. coli cells was suggested to be toxic to bacterial growth.