• Journal of Microbiology
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• v.37 no.2
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• pp.59-65
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• 1999

RecA protein can promote strand assimilation, homologous pairing, and strand exchange. All these reactions require DNA-dependent ATP hydrolysis by recA protein, and the activities of recA protein are affected by the ionic environment. In this experiment, DNA-dependent ATPase activity showed different sensitivity to anionic species. ATP hydrolysis and strand exchange were relatively sensitive to salt in the reactions with NaCl, strongly inhibited at 100 mM NaCl. However, the inhibition by sodium acetate or sodium glutamate was not observed at 50∼100 mM concentration. Addition of sodium glutamate to the standard reaction condition increased the apparent efficiency of ATP hydrolysis during strand exchange. The condition including 50∼100 mM sodium-glutamate might be similar to the physiological condition.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.135-141
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• 2001

Endocrine disruptors have been implicated in carcinogenesis in animal studies, but carcinogenetic effects on human remain controversial. In order to examine the genotoxicity of two common endocrine disruptors, Bisphenol A and Diethylstilbestrol, cytogenetic endpoints including chromosome aberration (CA), sister chromatid exchange (SCE), micronuclei (MN) analyses and DNA damage by single cell gel electrophoresis (SCGE) were assessed. The effects of Bisphenol A and Diethylstilbestrol on the frequencies of CA and MN were increased in a dose-dependent manner and that of Bispheol A was more significant by Kendall'$\tau$test. Bisphenol A and Diethylstilbestrol also increased the frequency of SCE. Bisphenol A and Diethylstilbestrol induced DNA damage in a dose-dependent manner and the DNA damage induced by Diethylstilbestrol in human blood lymphocytes was more significant.

• Korean Journal Plant Pathology
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• v.11 no.2
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• pp.173-178
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• 1995

동물계에서 항바이러스와관련된 dsRNA 의존성 인산화 효소(PKR)의 유전자를 식물체에서 발현시킬 경우 PKR에 의한 단백질합성 및 식물바이러스의 증식조절 가능성에 대한 기초자료를 확보하기 위하여 사람에서 분리된 PKR cDNA를 Agrobacterium 방법에 의하여 연초식물체(Nicotiana tabacum cv. Xanthi-nc)로 형질전환시켰다. HindIII/PstI처리에 의해 얻어지는 약 1.8kb의 phPKR cDNA절편을 일련의 유전자 조작 방법을 통하여 식물발현벡터인 pBI121에 도입하여, p12168을 재조합하였다. 이를 A. tumefaciens LBA 4404에 형질전환시켜 연초식물체형질 전환에 이용하였다. 2mg/l BA와 0.5mg/l NAA가 포함되고 100$\mu\textrm{g}$/ml의 kanamycin이 첨가된 MS배지에서 shooting시킨 후 phytohormone이 첨가되지 않은 MS배지상에서 rooting을 시켜 형질전환 연초식물체를 얻었으며, 형질전환식물체는 정상식물체와 유사한 생육양상을 나타내었다. 형질전환식물체의 유전자도입은 hPKR cDNA의 전사부여는 RT-PCR 방법에 의하여 확인되었다.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.264-269
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• 1994

To determine the nucleotide sequence of the ds RNA segment B containing the RNA dependent RNA polymerase (RdRp) gene of the DRT strain of infectious pancreatic necrosis virus (lPNV), the cDNA of the ds RNA segment B of the DRT strain of IPNV was synthesized using the reverse transcriptase (RT)-polymerase chain reaction (PCR) and its cDNA nucleotide sequence was determined. The DRT segment B was 2, 783 bp long and contained only a single long open reading frame (ORF) of 2, 535 bp in length. This ORF nucleotides encoded the VPl protein, the putative RdRp of IPNV. The VPl protein comsisted of 845 amino acids. The molecular weight of the RdRp, as deduced from the nucleotide sequence, is 94, 426. The nucleotide sequence of the ORF of the DRT showed 89.7% homology to the Jasper strain, but 80.8% to the Sp strain. The amino acid sequence of the ORF of the DRT sho.wed 97.6% homology to the Jasper strain, but 88.7% to the Sp strain. The conserved GTP-binding motif was detected in VPl protein.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.641-648
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• 2003

Changes of plasma DNA contents and serum biochemical values were measured in rats administered with $HgCl_2$ to investigate the in vivo cytotoxic effects of mercury and examine the usefulness of these changes as indicators of mercury exposure and diagnosis of mercury poisoning. Rats were given once intraperitonealy $HgCl_2$(0.13. 0.32. 0.8 and 2 mg/kg b.w) and the changes of plasma DNA contents and serum biochemical values were measured at the time of 2, 4, 8, 24, 48 and 72 hours after the administration of $HgCl_2$. Plasma DNA contents began to increase from 2 hours after the administration of $HgCl_2$ in all the treatment groups significantly compared to control with dose-dependent pattern. The levels of plasma DNA reached to peak at 48 hours as 2.77, 7.60, 15.46 and 16.51 times higher than control in each treatment group of 0.13, 0.32, 0.8 and 2 mg/kgb.w, respectively and remained to be higher until 72 hours after the administration. The values of creatine kinase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, blood urea nitrogen and glucose of serum were increased, however the values of alkaline phosphatase, total protein and triglyceride were decreased. These changes of increase and decrease showed dose-dependent pattern but the starting time, maintenance and magnitude of change were various and characteristic according to serum biochemical indices. Among the changes of serum biochemical values, those of aspartate aminotransferase, lactate dehydrogenase and blood urea nitrogen were apparently and significantly increased compared to control from 2 to 72 hours by the administration of 2 mg/kg $HgCl_2$. This study demonstrates that plasma DNA and serum biochemical values such as aspartate aminotransferase, lactate dehydrogenase, blood urea nitrogen and etc. are valuable as biomarkers for mercury exposure assessment and diagnosis of mercury poisoning.

• Journal of Microbiology
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• v.43 no.6
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• pp.516-522
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• 2005

The phosphorylation of C-terminal domain (CTD) of Rpb1p, the largest subunit of RNA polymerase II plays an important role in transcription and the coupling of various cellular events to transcription. In this study, its role in DNA damage response is closely examined in Saccharomyces cerevisiae, focusing specifically on several transcription factors that mediate or respond to the phosphorylation of the CTD. CTDK-1, the pol II CTD kinase, FCP1, the CTD phosphatase, ESS1, the CTD phosphorylation dependent cis-trans isomerase, and RSP5, the phosphorylation dependent pol II ubiquitinating enzyme, were chosen for the study. We determined that the CTD phosphorylation of CTD, which occurred predominantly at serine 2 within a heptapeptide repeat, was enhanced in response to a variety of sources of DNA damage. This modification was shown to be mediated by CTDK-1. Although mutations in ESS1 or FCP1 caused cells to become quite sensitive to DNA damage, the characteristic pattern of CTD phosphorylation remained unaltered, thereby implying that ESS1 and FCP1 play roles downstream of CTD phosphorylation in response to DNA damage. Our data suggest that the location or extent of CTD phosphorylation might be altered in response to DNA damage, and that the modified CTD, ESS1, and FCP1 all contribute to cellular survival in such conditions.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.313-318
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• 2010

Deinococcus radiodurans RecA protein, when bound to DNA, exhibits a DNA-dependent ATPase. In the absence of DNA, the rate of RecA protein-promoted ATP hydrolysis drops 1,000-fold under the physiological concentrations of salt. This DNA-independent activity can be stimulated to levels approximating those observed with DNA by adding high concentrations (approximately 1.6 M) of a wide variety of salts. This effect was characterized by varying salt concentration and comparing the effects of different ion types. The higher concentrations of salt stimulated the ATP hydrolysis by RecA protein in the absence of DNA. At 1.6 M chloride, the observed stimulation showed the following cation trend $K^+{\geq}Na^+$ > $NH_4^+$ and the following anion sequence was observed: $glutamate^- \; > \; C1^- \;> \; acetate^-\; > \;PO_4^-$ at 1.6 M $K^+$. The catalytic properties of the salt-stimulated ATP hydrolysis reaction was optimal between pH 7.0 and 8.0, which was similar to the double stran nded DNA-dependent ATPase activities of Deinococcus radiodurans RecA protein. In the absence of DNA the active species for ATP hydrolysis by RecA protein was shown to be an aggregate of three RecA protein molecules.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.309-316
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• 1990

The sequence of a 1795 bp restriction fragment containing the B. circulans F-2 gene for NaC1- dependent $\alpha$-amylase (CI-amylase) is reported. The probable coding region of the gene is 1005 base pairs (335 amino acida) long. The NaC1-dependent $\alpha$-amylase (el-amy) sequence shows an open reading frame (ORF) with the translated molecular weight of about 38, 006, which correspond to a molecular weight of about 35, 000 (Mi). The gene is preceded by the sequence resembling promoter for the vegetative B, subtitis RNA polymerases. These are followed by the sequences resembling a B. subtilis ribosome binding site 5 nucleotides before the first codon of the gene. Homologous regions with other amylases were found. The N-terminal sequences of the mature proteins expressed in E. eoli were identical to the N-terminal sequences which are anaIysed.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1071-1074
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• 2006

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.107-107
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• 2004