• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.196-205
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• 2015

A Sulfolobus-E. coli shuttle vector for an efficient expression of the target gene in S. acidocaldarius strain was constructed. The plasmid-based vector pSM21 and its derivative pSM21N were generated based on the pUC18 and Sulfolobus cryptic plasmid pRN1. They carried the S. solfataricus P2 pyrEF gene for the selection marker, a multiple cloning site (MCS) with C-terminal histidine tag, and a constitutive promoter of the S. acidocaldarius gdhA gene for strong expression of the target gene, as well as the pBR322 origin and ampicillin-resistant gene for E. coli propagation. The advantage of pSM21 over other Sulfolobus shuttle vectors is that it contains a MCS and a histidine tag for the simple and easy cloning of a target gene as well as one-step purification by histidine affinity chromatography. For successful expression of the foreign genes, two genes from archaeal origins (PH0193 and Ta0298) were cloned into pSM21N and the functional expression was examined by enzyme activity assay. The recombinant PH0193 was successfully expressed under the control of the gdhA promoter and purified from the cultures by His-tag affinity chromatography. The yield was approximately 1 mg of protein per liter of cultures. The enzyme activity measurements of PH0913 and Ta0298 revealed that both proteins were expressed as an active form in S. acidocaldarius. These results indicate that the pSM21N shuttle vector can be used for the functional expression of foreign archaeal genes that form insoluble aggregates in the E. coli system.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.64-64
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• 1996

Transgenic animal and cell line models which are recently developed in toxicology field combined with molecular biological technique, are powerful tools for studying of mutation in vivo and in vitro, respectively. The Big Blue mutagenesis assay system is one of the most widely used transgenic systems. Especially, for the study of direct acting mutagens, Big Blue cell line is very useful and powerful to evaluate mutagenicity because the mutation frequency and mutationspectrlun showed no distinct differences between cell line and animal. The Big Blue cell lines carry stably integrated copies of lambda shuttle vector containing lac I gene as a mutational target. These lambda shuttle vectors are useful for various mutagenesis related studies in eukaryotic system due to their ability to be exposed mutagen and then transfer a suitable target DNA sequence to it convenient organism for analysis. We tried to assess the mutagenic effect of 4-NQO with Big Blue cell line. After the treatment of 4-NQO, genomic DNA was isolated and lambda shuttle vector was packaged by in Vitro packaging and then these were plated on bacterial host in the presence of X-gal to screen mutation in the lac I. We determined MF as a ratio of blue plaques versus colorless plaques and now undergoing the mutation spectrum of 4-NQO in lac J gene sequence.

• Journal of Microbiology
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• v.35 no.2
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• pp.149-151
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• 1997

A plasmid vector with combined features of yeast shuttle vector and mammalian expression vector was constructed to facilitate expression of cloned gene in both cell-types. All necessary elements required for plasmid maintenance and selection in E. coli, yeast and mammalian cells were size-economically arranged in this plasmid. The numan cytomegalovirus (CMV) immediate early promoter and yeast GAL1 promoter were sequentially placed in front of the gene to be expressed. The synthetic splicing donor and acceptor sequences were inserted into the immediate upstream and downstream of the GAL1 promotor, allowing the CMV promotor to direct the expression of a given gene in mammalian cell environment by splicing out the interfering GAL1 promotor sequence. When the resulting vector containing LacZ as a gene was introduced into yeast and mammalian cells, both cells efficiently produced .betha.-galactosidase, dimonstrating its dual host usage.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1472-1476
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• 2006

Previous study demonstrated that the restriction barrier of Streptomyces griseus is almost completely bypassed by the Streptomyces-E. coli shuttle vectors passed through the E. coli GM161 strain and methylated with AluI and HpaII methyltransferases. The same DNA methylation of the genomic DNA fragments cloned the nonreplicative vectors generated integrative transformation and gene disruption of their chromosomal counterparts at high efficiencies in S. griseus. This result indicated that the efficiency of gene disruption depends on the efficient transfer of the incoming DNA into bacterial hosts.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.431-439
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• 2014

We report the construction of two Bacillus subtilis expression vectors, pBNS1/pBNS2. Both vectors are based on the strong promoter P43 and the ampicillin resistance gene expression cassette. Additionally, a fragment with the Shine-Dalgarno sequence and a multiple cloning site (BamHI, SalI, SacI, XhoI, PstI, SphI) were inserted. The coding region for the amyQ (encoding an amylase) signal peptide was fused to the promoter P43 of pBNS1 to construct the secreted expression vector pBNS2. The applicability of vectors was tested by first generating the expression vectors pBNS1-GFP/pBNS2-GFP and then detecting for green fluorescent protein gene expression. Next, the mannanase gene from B. pumilus Nsic-2 was fused to vector pBNS2 and we measured the mannanase activity in the supernatant. The mannanase total enzyme activity was 8.65 U/ml, which was 6 times higher than that of the parent strain. Our work provides a feasible way to achieve an effective transformation system for gene expression in B. subtilis and is the first report to achieve B. pumilus mannanase secretory expression in B. subtilis.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.678-682
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• 2010

The deletion of sti from the Streptomyces plasmid pIJ101 made its derivative pHZ1358 an efficient vector for gene disruption and replacement. Here, pHZ1358 was further optimized by the construction of a derivative plasmid pJTU1278, in which a cassette carrying multiple cloning sites and a lacZ selection marker were introduced for convenient plasmid construction in E. coli. In addition, the oriT region of pJTU1278 was also deleted, generating a vector (pJTU1289) that can be used specifically for PCR-targeting. The efficient usage of these vectors was demonstrated by the deletion of the gene involved in avermectin biosynthesis in S. avermitilis.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.312-320
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• 2000

Abstract The full sequence of the plasmid pKJ36, which was derived from Bifidobacterium longum KJ, was determined and analyzed to construct shuttle vectors between E. coli and Bifidobacterium. The plasmid pKJ36 was composed of 3,625 base pairs with a 65.1% G+C content. The structural organization of pKJ36 was highly similar to that of pKJ50, and the three major ORFs on pKJ36 showed high amino acid sequence homologies with those of pKJ50. The putative proteins coded by these three ORFs were designated as RepB (32.0 kDa, pI=9.25), MembB (29.0 kDa, pI=12.25), and MobB (39.0 kDa, pI=IO.66), respectively. The amino acid sequence of RepB showed a 57% identity and 70% similarity with that of the RepA protein of pKJ50. Upstream of the repB gene, the so-called iteron sequence was directly repeated four-and-ahalf times and a conserved dnaA box was identified. An amino acid sequence comparison between the MobB and MobA of pKJ50 revealed a 48% identity and 61 % similarity. A conserved oriT sequence with an inverted repeat identical to that of pKJ50 was also found upstream of the mobB gene. A hydropathy analysis of MembB revealed four possible transmembrane regions. The expressions of the repB and membB genes were confirmed by RT-PCR. The in vitro translation reaction of pKJ36 showed protein bands with anticipated sizes with respect to each putative gene product. S 1 endonuclease treatment and Southern hybridization suggested that pKJ36 replicates by a rolling circle mechanism via a single-stranded DNA (ssDNA) intermediate. A shuttle vector between E. coli and Bifidobacterium sp. was constructed using the pKJ36, pBR322, and staphylococcal chloramphenicol acetyl transferase (CAT) gene. The successful transformation of the Bifidobacterium strains was shown by Southern hybridization and PCR. The transformation efficiency differed from strain to strain and, depending on the electroporation conditions, with a range between $1.2{\times}10^1-2.6{\times}10^2{\;}cfu/\mu\textrm{g}$ DNA.X> DNA.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.70-79
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• 2014

In an attempt to develop a variety of expression vector systems for Corynebacterium glutamicum, six types of promoters, including $P_{tac}$, $P_{sod}$, $P_{sod}$ with a conserved Shine-Dalgarno (SD) sequence from C. glutamicum, $P_{ilvC}$, $P_{ilvC}$ with a conserved SD-1 ($P_{ilvC-M1}$), and $P_{ilvC}$ with a conserved SD-2 ($P_{ilvC-M2}$), were cloned into a modified shuttle vector, pCXM48. According to analysis of promoter strength by quantitative reverse transcription PCR, $P_{sod}$ and $P_{sod-M}$ were superior to tac and ilvC promoters in terms of transcription activity in C. glutamicum. All of the promoters have promoter activities in Escherichia coli, and $P_{sod-M}$ displayed the highest level of transcriptional activity. The protein expression in constructed vectors was evaluated by measuring the fluorescence of green fluorescent protein (GFP) and SDS-PAGE. C. glutamicum harboring plasmids showed GFP fluorescence with an order of activity of $P_{ilvC}$ > $P_{ilvC-M1}$ > $P_{sod}$ > $P_{ilvC-M2}$ > $P_{sod-M}$, whereas all plasmids except pCSP30 with $P_{sod}$ displayed fluorescence activities in E. coli. Of them, the strongest level of GFP was observed in E. coli with $P_{sod-M}$, and this seems to be due to the introduction of the conserved SD sequence in the translational initiation region. These results demonstrate that the expression vectors work well in both C. glutamicum and E. coli for the expression of target proteins. In addition, the vector systems harboring various promoters with different strengths, conserved SD sequences, and multiple cloning sites will provide a comfortable method for cloning and gene expression, and consequently contribute to the metabolic engineering of C. glutamicum.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.476-483
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• 1988

Yeat-Escherichia coli shuttle vectors were constructed by combination of various functional segments such as autonomous replicating sequence (ARS1), centromere region (CEN3), origin of replication of 2 $\mu$m plasmid (2 $\mu$m OR). Transformation efficiency, stability and copy number of constructed vectors were analyzed in yeast strains, SHY4(cir$^+$) containing 2 $\mu$m plasmid and NNY1(cir$^{\circ}$) without it. The results showed that centromere containing plasmids were very stable and existed at one copy per cell; fused replication system (2$\mu$m OR and ARS1) containing Plasmids were more stable and higher copy number than one replicon containing plasmids ; presence of endogenous 2$\mu$m plasmid influenced on stability and copy number of 2 $\mu$m based plasmids.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.202-205
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• 2000

A gene coding $endo-{\beta}$,-1, 4 glucanase from Actinomyces sp. KNG40 and phytase from Hansenula polymorpha were cloned into Esherichia coli JM101 by using E. coli/Lactobacillus shuttle vector pNZ3004 and pNZ123. The plasmid p3PS(1-4) and p123(1-4) have slpA promoter and slpA signal sequence. So, I constructed expression vectors, p3PS(1-4)Endo, phy and p123(1-4)Endo, phy. These constructed vector was transformed in target host Lactobacillus gasseri and reutri. These transformed host expressed endoglucanase and phytase as extracellular fraction. In the enzyme activity of the same vector, host L, gasseri was higher activity than L. reuteri. This indicates that L. gasseri recongnize promoter and signal sequence very well.