• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.369-376
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• 1992

This paper dealt with plasmid DNA profile in 98 Salmonella(S) isolated from pigs and cattle sources in Taegu, Gyeongbook and Gyeongnam during the period from 1984 to 1987. Also we were studied for restriction enzyme analysis of the plasmid DNA, and mouse infection, Sereny test and normal setum resistance test in guinea pig for S typhimurium and S enteritidis harbored or cured 60 megadalton(Md) plasmid and 36 Md plasmid, respectively. Of the 13 Salmonella isolated from cattle, 7 Salmonella harbored one or more plasmids and molecular sizes of the large plasmids were 60 Md for S typhimurium and 36 Md for S enteritidis. Of the 85 Salmonella isolated from pigs, 47 Salmonella were confirmed as being one or more plasmids, and all the S typimurium stains harbored 60 Md plasmid. In enzyme digestion with 8 types of restriction endonuclease for 60 Md plasmid DNA of S typhimurium, cleavage patterns were varied to enzymes, and the DNA was segmented into 4 to 15 fragments. In restriction enzyme analysis of 36 Md plasmid DNA obtained from four strains of S. enteritidis, the DNA showed the same cleavage patterns obtained with Eco RI, Hind III and Bam H I, and was segmented into 3 to 5 fragments. In virulence for mice by measuring the 50% lethal dose ($LD_{50}$), the $LD_{50}$ values obtained for 60 Md virulence-associated plasmid harbored strains of S typhimurium and 36 Md virulence-associated plasmid of S enteritidis were up to $10^4$-fold lower than the values obtained for the plasmid-cured strains of the same serotype. Only the plasmid harbored strains were resistant to the bactericidal activity of 90% guinea pig serum, and only they gave positive responses in sereny test. We suggested that their plasmid DNA might be associated with virulence for mice.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.40-45
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• 1987

The gene for the Bdi I modification enzyme, which is one of Bdi I restriction-modification system, fromBrevibacterium divaricatum FERM 5948 was cloned and expressed in E. coli. For cloning of the Bdi I methylase gene, we have initially used three cloning site(EcoRI, BamHI and Sal I) of plasmid vector pBR 322 and adopted the retransformation method after Bdi I restriction endonuclease cleavage. Selection of transformants carrying the gene was based on the resistance of the modified plasmid encoding the enzyme to cleavage by Bdi I restriction enzyme, and the recombinant plasmid pBDIM 116 containing 5.6kb EcoRI insery was proved to carry the gene. Crude cell extracts prepared from strains carrying the plasmid pBDIM 116 contained an S-adenosylmethionine-dependent methyltransferase activity specific for the Bdi I recognition site, ATCGAT. The restriction map was constructed with 11 restriction enzyme, and the Bdi I restriction-modification system was also discussed.

• BMB Reports
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• v.39 no.2
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• pp.208-215
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• 2006

The human ribosomal protein S3 (rpS3) was expressed in E. coli using the pET-I5b vector and the monoclonal antibodies (mAbs) were produced and characterized. A total of five hybridoma cell lines were established and the antibodies recognized a single band of molecular weight of 33 kDa on immunoblot with purified rpS3. When the purified rpS3 was incubated with the mAbs, the UV endonuclease activity of rpS3 was inhibited up to a maximum of 49%. The binding affinity of mAbs to rpS3 determined by using a biosensor technology showed that they have similar binding affinities. Using the anti-rpS3 antibodies as probes, we investigated the cross-reactivities of various other mammalian brain tissues and cell lines, including human. The immunoreactive bands on Western blots appeared to be the same molecular mass of 33 kDa in all animal species tested. They also appear to be extensively cross-reactive among different organs in rat. These results demonstrated that only one type of immunologically similar rpS3 protein is present in all of the mammalian brain tissues including human. Furthermore, these antibodies were successfully applied in immunohistochemistry in order to detect rpS3 in the gerbil brain tissues. Among the various regions in the brain tissues, the rpS3 positive neurons were predominantly observed in the ependymal cells, hippocampus and substantia nigra pars compacta. The different distributions of rpS3 in brain tissues reply that rpS3 protein may play an important second function in the neuronal cells.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.312-319
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• 2002

The Sporosarcina psychrophilia pyrB gene, which encodes aspartate transcarbamylase (ATcase), was cloned on Sau3AI restriction endonuclease fragment inserted into pUC19 plasmid vector, S. psychrophilia pyrB gene was expressed in Escherichia coli pyrB mutant for the complementation test. The sequence of 2,606 nucleotides including putative pyrB gene was determined. The region contained one full open reading frame (ORf) and two partial ORFs. The deduced amino acid sequence of the second ORF showed 59% identity with that of Bacillus caldolyticus ATCase. The first and third partial ORFs were closely related to the uracil permease (pyrP) and dihydroorotase (pyrC), respectively. Besides, potential terminator, antiterminator, and anti-antiterminator structures were found in the intergenic region between pyrP and pyrB. These results suggested that S. psychrophilia pyrimidine nucleotide biosynthesis genes are clustered as well as other Bacillus sp. Over-expressed product of pyrB encoding ATCase was purified and analyzed by the SDS-PAGE. The purified PyrB protein turned out to be molecular mass of 27 kDa and showed ATCase activity.

• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.534-542
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• 2021

Single-molecular guide RNA (sgRNA) plays a role in recognizing the DNA target sequence in CRISPR technology for genome editing and gene expression control. In this study, we systematically compared the length of the target recognition sequence in sgRNAs required for genome editing using Cas9-NG (an engineered Cas9 recognizing 5'-NG as PAM sequence) and gene expression control using deactivated Cas9-NG (dCas9-NG) by targeting the gal promoter in E. coli. In the case of genome editing, the truncation of three nucleotides in the target recognition sequence (TRS) of sgRNA was allowed. In gene expression regulation, we observed that target recognition and binding were possible even if eleven nucleotides were deleted from twenty nucleotides of the TRS. When 4 or more nucleotides are truncated in the TRS of the sgRNA, it is thought that the sgRNA/Cas9-NG complex can specifically bind to the target DNA sequence, but lacks endonuclease activity to perform genome editing. Our study will be helpful in the development of artificial transcription factors and various CRISPR technologies in the field of synthetic biology.