• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.322-328
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• 2003

The Transformation-Associated Recombination (TAR) cloning technique allows selective isolation of chromosomal regions and genes from complex genomes. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosomal region of interest. This technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector that has 5'and 3' gene targeting sequences. In this study, we examined the minimum size of specific hooks required for a single-copy gene isolation and compared the utility of different TAR vectors, radial and unique vectors, by cloning the same single-copy gene. The efficiency of TAR cloning of the hHPRT gene was same using hooks varying from 750 to 63 bp. The number of transformants decreased approximately 20-fold when the TAR vector contained two unique hooks versus using a radial vector, but the percentage of positive recombinants increased over 2-fold when a unique TAR vector was used. Therefore, we suggest that the two-unique TAR vector is suitable for general TAR cloning given its high selectivity, and the radial TAR vector is more suitable when genomic DNA is in limited quantity, for example, DNA isolated from pathological specimens. Moreover, we confirm the minimal length of a unique sequence in a TAR vector is approximately 60 bp for a single-copy gene isolation.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1481-1483
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• 2010

We constructed an efficient T-vector, pTQEST216T that employed an engineered esterase as an indicator for direct cloning of PCR products. After ligation of the XcmI-digested vector with PCR products, this cloning system could easily discriminate positive clones owing to insertional inactivation of the esterase reporter. Additionally, PCR products were efficiently cloned into this vector without the gel purification steps, owing to the well-designed multi-cloning site that was in-frame fused at the circularly permutated gap of the reporter.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.264-266
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• 2000

A new GFP-based T-vector for cloning of PCR products was developed by using a green fluorescent protein (GFP) as a mafker. In order to facilitate the DNA inserts, multiple restriction sites, SP6 and T7 RNA polymerase promoter sites, were introduced close to the PCR DNA insertion site of a pCRGv vector. The XcmI-digested pHNT plasmid can be used to clone a 3' A-overhanged PCR DNA amplified by Taq DNA polymerase. A potential method of easing some difficulties from its use along with its cost savings proveded by this vector are likely to lead to the replacement of other T-vectors for PCR DNA cloning.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.262-273
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• 1987

The replication region of the chloramphenical resistance plasmid pSBK203 of Staphylococcus aureus was cloned using pBR322 and pBD9 as vectors. Cloned replication tegion and chloramphenicol resistance gene were recombined to pBR322. The reconstructed vector behaved as a shuttle vector for E. coli and B. subtilis.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.126-130
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• 1988

Promoters of an alkali-tolerant Bacillus sp. isolated from soil have been cloned in Bacillus subtilis using promoter probe vector pPL703. The CAT specific activity of a clone harboring the strongest promoter activity among these transformants was 8.01. This activity was 2.5 times higher than that of Bacillus subtilis harboring expression vector pPL708 and was increased after the end of the logarithmic growth phase. In the 2.8kb of inserted DNA fragment, BamHI and Sal I recognition sites were located.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.98-102
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• 1990

A strain of Erwinia spp. was selected from the soil for the production of bacteriocin to the root rot plant pathogen. Bacteriocin producing gene was not located on plasmid but on chromosome. Genomic library of Erwinia spp. were made by using pLAFR 3 as a vector system for cloning of the gene. It was been cloned and expressed in E. coli DH 5 . Bacteriocin producing colony was composed of pLAFR 3 vector and 3.0 kb EcoRI fragment of Erwinia spp. ehromosomal DNA. The inserted fragment (3.0 kb) was possessed a EcoRI and BarnHI restriction sites.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.128-134
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• 2003

Transformation-associated recombination (TAR) cloning is based on co-penetration into yeast spheroplasts of genomic DNA along with TAR vector DNA that contains 5'- and 3'-sequences (hooks) specific for a gene of interest, followed by recombination between the vector and the human genomic DNA to establish a circular YAC. Typically, the frequency of recombinant insert capture is 0.01-1% for single-copy genes by TAR cloning. To further refine the TAR cloning technology, we determined the effect of GC content on target hooks required for gene isolation utilizing the $Tg\cdot\AC$ mouse transgene as the targeted region. For this purpose, a set of vectors containing a B1 repeated hook and Tg AC-specific hooks of variable GC content (from 18 to 45%) was constructed and checked for efficiency of transgene isolation by radial TAR cloning. Efficiency of cloning decreased approximately 2-fold when the TAR vector contained a hook with a GC content ～${\leq}23$% versus ～40%. Thus, the optimal GC content of hook sequences required for gene isolation by TAR is approximately 40%. We also analyzed how the distribution of high GC content (65%) within the hook affects gene capture, but no dramatic differences for gene capturing were observed.

• Journal of Life Science
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• v.16 no.6
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• pp.1036-1043
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• 2006

The transformation-associated recombination (TAR) cloning technique allows selective isolation of chromosome regions or genes from complex genome. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosome region of interest. This method involves homologous recombination during spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences (hooks). To examine whether TAR cloning can be applied to the isolation of gene homologues, we chose the HPRT genes from human and mouse genome. As results, the yield of positive clones for HPRT gene from human and mouse genome when using a TAR vector containing mHPRT hook or hHPRT hook was almost same level. Analysis of the gap regions in mHPRT revealed that they contain abnormalities that could result in instability of the sequences. In conclusion, we were able to use the TAR cloning technology to isolate gene homologue (orthologue) from nonidentical genome. Moreover, the use of the TAR cloning system may accelerate work on closing the remaining gaps in mammalian genome to achieve the goal of annotation of all mammalian genes.

• Journal of Microbiology and Biotechnology
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• v.3 no.1
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• pp.6-11
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• 1993

An autonomously replicating sequence (Kf-ARS1) of Kluyveromyces fragilis was cloned from the genomic library which was constructed using pHN134 as a cloning vector to make a new host-vector system for the production of heterologous protein from K. fragilis as a host. The cloning vector pHN134 was composed of $Km^r, Ap^r$ and multiple cloning site in LacZ . A clone carrying Kf-ARS1 was isolated and the recombinant plasmid was designated as pIKD102. The cloned fragment was 2.3 kb (EcoRI/EcoRI) in length. Subcloning experiment showed that the region for ARS activity was 1.5 kb (SalI/EcoRI) fragment. It was shown that the Kf-ARS1 was active in Saccharomyces cerevisiae and Kluyveromyces fragilis.

• BMB Reports
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• v.39 no.1
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• pp.22-25
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• 2006

The gene encoding MPB83 from Mycobacterium bovis Vallee111 chromosomal DNA was amplified by using polymerase chain reaction (PCR) technique, and the PCR product was approximately 600bp DNA segment. Using T-A cloning technique, the PCR product was cloned into pGEM-T vector and the cloning plasmid pGEM-T-83 was constructed successfully. pGEM-T-83 and pET28a(+) were digested by BamHI and EcoRI double enzymes. The purified MPB83 gene was subcloned into the expression vector pET28a(+), and the prokaryotic expression vector pET28a-83 was constructed. Plasmid containing pET28a-83 was transformed into competence Escherichia coli BL21 (DE3). The bacterium was induced by isopropyl-$\beta$-D-thiogalactopyranoside (IPTG) and its lysates were loaded directly onto sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), approximately 26 kDa exogenous protein was observed on the SDS-PAGE. The protein was analyzed using Western-blotting. The results indicated that the protein was of antigenic activity of M. bovis. The results were expected to lay foundation for further studies on the subunit vaccine and DNA vaccine of MPB83 gene in their prevention against bovine tuberculosis.