• Journal of Microbiology
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• 제45권5호
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• pp.418-421
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• 2007

The nucleotide at position 791(G791) of E. coli 16S rRNA was previously identified as an invariant residue for ribosomal function. In order to characterize the functional role of G791, base substitutions were introduced at this position, and mutant ribosomes were analyzed with regard to their protein synthesis ability, via the use of a specialized ribosome system. These ribosomal RNA mutations attenuated the ability of ribosomes to conduct protein synthesis by more than 65%. A transition mutation (G to A) exerted a moderate effect on ribosomal function, whereas a transversion mutation (G to C or U) resulted in a loss of protein synthesis ability of more than 90%. The sucrose gradient profiles of ribosomes and primer extension analysis showed that the loss of protein-synthesis ability of mutant ribosomes harboring a base substitution from G to U at position 791 stems partially from its inability to form 70S ribosomes. These findings show the involvement of the nucleotide at position 791 in the association of ribosomal subunits and protein synthesis steps after 70S formation, as well as the possibility of using 16S rRNA mutated at position 791 for the selection of second-site revertants in order to identify ligands that interact with G791 in protein synthesis.

• 미생물학회지
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• 제42권2호
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• pp.156-159
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• 2006

Escherichia coli 16S rRNA의 잘 보존된 부분인 790 loop의 즉흥진화를 통한 분석에서 리보솜의 단백질 수행기능을 위해서 필수불가결한 것으로 추측되는 789번 위치에 염기치환을 유발하여 제작한 변이체 리보솜의 기능을 chloramphenicol acetyltransfernse mRNA의 단백질로의 번역능력 차이에 따른 chloramphenicol에 대한 저항성의 정도를 측정함으로써 분석하였다. 예상했던 바와 같이 모든 변이체 리보솜의 단백질 합성능력은 현저히 저하되었으며, 789 염기의 단백질합성에서의 기능을 규명하기 위하여 16S rRNA 변이체의 기능을 회복시키는 이차복귀돌연변이(second-site revertant)를 발췌하는 효과적인 유전학적 실험방법을 개발하였다.

• 미생물학회지
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• 제44권4호
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• pp.271-276
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• 2008

최근 단백질 합성 과정 중 라이보솜의 일시적인 정지에 의한 라이보솜의 A자리에서 전사체가 분해되는 현상이 여러 생명체에서 보고되었다. 이러한 현상이 라이보솜의 작은 소단위체를 이루고 있는 SSU rRNA의 기능과 관련 있는지를 알아보기 위해, SecM에서 유래한 접착펩타이드에 의한 라이보솜 정지를 우회하는 SSU rRNA 돌연변이체 발굴을 위한 유전학적 시스템을 개발하였다. 이 시스템에서는 SecM에서 유래한 접착펩타이를 포함하는 CAT 단백질을 코딩하는 CAT-SecM 전사체가 플라스미드에서 유래한 SSU rRNA를 포함한 재조합 라이보솜에 의해서만 해독된다. 이러한 재조합 라이보솜은 접착펩타이드를 합성한 후 CAT-SecM mRNA 상에서 일시 정체하며, 재조합 라이보솜의 발현은 이 전사체의 양을 감소시키는 것을 확인하였다. 이러한 결과는 개발된 시스템을 이용해 라이보솜 검지를 우회하는 SSU rRNA 돌연변이체의 선별이 가능하다는 것을 보여주며, 이러한 변이체에 대한 연구는 단백질 합성 단계에서 일어나는 라이보솜 정지와 전사체 절단 현상에 있어서, SSU rRNA의 역할을 규명하는데 기여할 것이다.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.256-260
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• 1991

In B. subtilis, $\alpha$-amylase synthesis is regulated by amyR located directly on the upstream of amyE. Three different amyR alleles have been reported, amyR1, amyR2 and amyR3. Strains bearing the gra-10 mutation which confers derepression for catabolite repression has GlongrightarrowA transition mutation at ＋5 of amyR1. S1 nuclease mapping demonstrated that transcription initiated at 8 bases downstream from the -10 region of putative E$\sigma^{A}$ promoter P1 in amyR1 and gra-10. In amyR2, the major transcription initiatd at the same place and the minor, 10 bases downstream from -10 of P2. The transcript from P2 contributed approximately 15-20% of total amyE mRNA. S1 nuclease protection experiment indicated that amyE mRNA levels corresponded to the rate of synthesis assumed by specific activities of $\alpha$-amylase in culture supernatants, suggesting that $\alpha$-amylase synthesis is regulated at the level of transcription.n.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.804-819
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• 2003

It has been known that adenine is a very important material in living cells. Because, adenine is a member of nucleotide base, so it takes part in DNA, RNA and ATP synthesis. There are many reports that adenine participated in ingredients, especially DNA, RNA, NADH and ATP, affect on the cell. As well adenosine, conjugated adenine to glycoside, was known to anti-wrinkle compound. But there is no report whether adenine shows a good effect on the skin, especially anti-wrinkle. So, in this study, we tested whether adenine affects cell proliferation, collagen synthesis, collagenase synthesis inhibition in human dermal fibroblasts. In addition, we performed clinical study with adenine cream. Cell proliferation effect was tested by MTT assay. Collagen and collagenase synthesis were measured by Immunoassay with ELISA kit. Clinical study was performed by IECK according to KFDA Functional Cosmetic method. The results of cell proliferation show that 10$^{-6}$ ~10$^{-8}$ ％ of adenine increases cell proliferation about 50 ％ compare with non-treated control. At 10$^{-7}$ ~10$^{-10}$ ％, adenine increases type I collagen synthesis about 50％, decreases type I collagenase about 22％ compare with non-treated control. The results of clinical study show that 0.05％ adenine treated group reduces wrinkle significantly compare with placebo treated group. Therefore adenine may be a new anti-wrinkle candidate, through increases cell proliferation and collagen synthesis dramatically. And it decreases collagenase synthesis. So adenine could be used as a new anti-wrinkle agent.

• Asian-Australasian Journal of Animal Sciences
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• 제11권5호
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• pp.545-549
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• 1998

The influence of refeeding with either vitamin, mineral, fibre of water on protein synthesis and mRNA content in the liver and breast muscle of fasted chicks was investigated. At 15 d of age, chicks were fasted for 2 d and then refed either vitamin, mineral, fibre or water. The fractional synthesis rate (FSR) of protein was measured after 30 min of refeeding by using a large dose injection of L - 2, $6[^3H]$ phenylalanine. In the liver, FSR was reduced by fasting and tended to increase but not significantly by refeeding with vitamin or mineral. FSR was not affected by refeeding with fibre or water. There was no influence of fasting and refeeding on ribosomal capacity (the RNA : protein ratio) and ribosomal efficiency (total protein synthesised per total RNA). The absolute synthesis rate (ASR) of liver protein and hepatic mRNA content were reduced by fasting and unchanged by refeeding. In the muscle, FSR, ASR and mRNA content were significantly decreased by fasting and not recovered by refeeding with either vitamin, mineral, fibre or water. It concluded that vitamin, mineral, fibre and water have little capacity to stimulate liver and muscle protein synthesis reduced by fasting.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1204-1207
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• 2007

Structural analyses have shown that nucleotides at the positions 770 and 771 of Escherichia coli 16S rRNA are implicated in forming one of highly conserved intersubunit bridges of the ribosome, B2c. To examine a functional role of these residues, base substitutions were introduced at these positions and mutant ribosomes were analyzed for their protein synthesis ability using a specialized ribosome system. The results showed requirement of a pyrimidine at the position 770 for ribosome function regardless of the nucleotide identity at the position 771. Sucrose gradient profiles of ribosomes revealed that the loss of protein-synthesis ability of mutant ribosome bearing a base substitution from C to G at the position 770 stems from its inability to form 70S ribosomes. These findings indicate involvement of nucleotide at the position 770, not 771, in ribosomal subunit association and provide a useful rRNA mutation that can be used as a target to investigate the physical interaction between 16S and 23S rRNA.

• Molecules and Cells
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• 제19권2호
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• pp.239-245
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• 2005

Factor for inversion stimulation (FIS), the Escherichia coli protein, is a positive regulator of the transcription of genes that encode stable RNA species, such as rRNA and tRNA. Transcription of the rnpB gene encoding M1 RNA, the catalytic subunit of E. coli RNase P, rapidly declines under stringent conditions, as does that of other stable RNAs. There are multiple putative FIS binding sites upstream of the rnpB promoter. We tested whether FIS binds to these sites, and if so, how it affects rnpB transcription. In vitro binding assays revealed specific binding of FIS to multiple sites in the rnpB promoter region. Interestingly, FIS bound not only to the upstream region of the promoter, but also to the region from +4 to +18. FIS activated rnpB transcription in vitro, but the level of activation was much lower than that of the rrnB promoter for rRNA. We also examined the effects of FIS on rnpB transcription in vivo using isogenic $fis^+$ and $fis^-$ strains. rnpB transcription was higher in the $fis^-$ than the $fis^+$ cells during the transitions from lag to exponential phase, and from exponential to stationary phase.

• Journal of Microbiology
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• 제34권1호
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• pp.37-37
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• 1996

The internal regions of nuclear small subunit rRNA from 6 plaeurotus species and 5 Pleurotus ostreatus strains were amplified by PCR and sequenced. The DNA sequences of 8 Pleurotus strains (P. ostreatus NFFA2, NFFA4501, NFFA4001, KFFA4001, KFCC11635, P florida, P. florida, P. sajor-cuju, P. pulmonarius, and P. spodoleucus) were idential, but P. cornucopiae differed from them in two bases out of 605 bases. However, p[hylogenetic analysis of the sequences by DNA-distance matrix and UPGMA methods showed that P. ostreatus NFFA2m1 and NFFA2m2, known as mutants of P. ostreatus NFFA2, belonged to anther group of Basidiomycotina, which is close to the genus Auricularia. The difference of the SSU rDNA sequences of P. cornucopiae from other Pleurotus species tested corresponds to the difference of mitochondrial plasmid type present in Pleurotus species as observed by Kim et al. (1993, Korean J. Microbiol. 31, 141-147).ishement of silencing at the HMR/hsp82 locus can occur in G1-arrested cells. Cell cycle arrest at G1 phase was achieved by treatment of early log a cell cultures with .alpha.-factor mating pheromone, which induces G1 arrest. The result suggests that passage through S phase (and therefore DNA replication) is nor required for re-establishing silencer-mediated repression at the HMNRa/HSP82 locus. Finally, to test whether de nono protein synthesis is required for re-establishment of silencer-mediated repression, cells were pretreated with cycloheximide (500 /.mu.g/ml) 120 min. It was apparent that inhibiting protein synthesis delays, but does not prevent, re-establishment of silencer-mediated repression. Altogether, these results indicate that re-establishment of silencer-mediated repression is not dependent on the DNA replication and has no requirement for protein synthesis.

• 한국미생물·생명공학회지
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• 제39권1호
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• pp.93-96
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• 2011

대장균의 16S rRNA 염기 중 진화적으로 매우 보존되어 있는 B2c 인터브리지의 구성요소 중 하나인 C770염기에 치환을 일으키면 단백질 합성이 저하되는 것으로 알려져 있다. 이 연구에서는 770 위치에 C에서 G로 염기치환(C770G)된 16S rRNA의 기능을 회복시키는 이차복귀돌연변이(secondsite revertant)를 얻기 위해 16S rRNA를 암호화하는 DNA 부분에 무작위로 염기치환을 유발시켜, 재조합 리보솜이 번역하는 CAT mRNA로부터의 단백질 합성능력이 향상된 클론을 선별하였다. 이 실험으로 C770G 염기치환을 가진 변이체 리보솜의 단백질 합성능력을 일부 회복시키는 하나의 이차복귀돌연변이체를 획득하였으며, DNA 염기분석을 통하여 C569G와 U904C 염기치환을 가진 것을 확인하였다. 이러한 연구결과를 이용하여 770 염기가 단백질 합성 과정에서 16S rRNA의 어떤 다른 부분과 결합을 하는지, 또한 그러한 결합으로 이루어지는 구조가 가지게 되는 기능은 무엇인지 등에 대한 리보솜의 구체적인 단백질 합성기작 연구에 도움이 될 것으로 기대한다.