• Archives of Pharmacal Research
• /
• v.21 no.3
• /
• pp.291-297
• /
• 1998

Cop protein has been overexpressed in Escherichia coli using a T7 RNA polymerase system. Purification to apparent homogeneity was achieved by the sequential chromatography on ion exchange, affinity chromatography, and reverse phase high performance liquid chromatography system. The molecular weight of the purified Cop was estimated as 6.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). But the molecular mass of the native state Cop was shown to be 19 kDa by an analytical high performance size exclusion chromatography, suggesting a trimer-like structure in 50 mM Tris-HCI buffer (pH 7.5) containing 100 mM NaCl. Cop protein Was calculated to contain $39.1% {\alpha}-helix, 16.8% {\beta}-sheet$, 17.4% turn, and 26.8% random structure. The DNA binding property of Cop protein expressed in E. coli Was preserved during the expression and purification process. The isoelectric point of Cop was determined to be 9.0. The results of amino acid composition analysis and N-terminal amino acid sequencing of Cop showed that it has the same amino acid composition and N-terminal amino acid sequence as those deduced from its DNA sequence analysis, except for the partial removal of N-terminal methionine residue by methionyl-aminopeptidase in E. coli.

• Plant Biotechnology Reports
• /
• v.2 no.4
• /
• pp.227-231
• /
• 2008

D-class cyclins play important roles in controlling the cell cycle in development and in response to external signals by forming the regulatory subunit of cyclin-dependent kinase (CDK) complexes. To evaluate the effects of D-class cyclins in transgenic rice plants, Arabidopsis cyclin D2 gene (CycD2) was linked to the maize ubiquitin1 promoter (Ubi1) and introduced into rice by the Agrobacterium-mediated transformation method. Genomic deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and Western blot hybridizations of the Ubi1:-CycD2 plants revealed copy number of transgene and its increased expression in leaf and callus cells at messenger RNA (mRNA) and/or protein levels. The H1 kinase assay using the immunoprecipitates of protein extracts from the Ubi1:CycD2 plants and nontransgenic controls demonstrated that the introduced Arabidopsis CycD2 forms a functional CycD2/CDK complex with an unidentified CDK of rice. Shoot and root growth was enhanced in the Ubi1:CycD2 seedlings compared with nontransgenic controls, together, suggesting that Arabidopsis cyclin D2 interacts with a rice cyclin-dependent kinase, consequently enhancing seedling growth.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.9
• /
• pp.864-869
• /
• 1995

Investigation of the structures of the gangliosides has proven to be very important in the understanding of their biological roles such as regulation of differentiation and growth of cells. We used nuclear magnetic resonance spectros-copy in order to investigate the structure of GA1. In order to do this, the assignment of spectra is a prerequisite. Since GA1 does not have polar sialic acid, the spectral overlap is severe. In order to solve this problem, we use 2D NMR spectroscopy and heteronuclear 1H/13C correlated spectroscopy in this study. Here, we report the complete assignment of the proton and the carbon spectra of the GA1 in DMSO-d6-D20 (98:2, v/v). These assignments will be useful for interpreting 1H and 13C NMR data from uncharacterized oligosaccharides and for determining the linkage position, the number of sugar rings, and the sequence of new ganglioside. Amide proton in ring Ⅲ shows many interring nOes and has intramolecular hydrogen bonding. This appears to be an important factor in tertiary folding of GA1. Based on this assignment, determination of three dimensional structure of GA1 will be carried out. Studies on the conformational properties of GA1 may lead to a better understanding of the molecular basis of its functions.

• Biomedical Science Letters
• /
• v.24 no.4
• /
• pp.292-304
• /
• 2018

Microbes is becoming increasingly forensic possibility as a consequence of advances in massive parallel sequencing (MPS) and bioinformatics. Human DNA typing is the best identifier, but it is not always possible to extract a full DNA profile namely its degradation and low copy number, and it may have limitations for identical twins. To overcome these unsatisfactory limitations, forensic potential for bacteria found in evidence could be used to differentiate individuals. Prokaryotic cells have a cell wall that better protects the bacterial nucleoid compared to the cell membrane of eukaryotic cells. Humans have an extremely diverse microbiome that may prove useful in determining human identity and may even be possible to link the microbes to the person responsible for them. Microbial composition within the human microbiome varies across individuals. Therefore, MPS of human microbiome could be used to identify biological samples from the different individuals, specifically for twins and other cases where standard DNA typing doses not provide satisfactory results due to degradation of human DNA. Microbial forensics is a new discipline combining forensic science and microbiology, which can not to replace current STR analysis methods used for human identification but to be complementary. Among the fields of microbial forensics, this paper will briefly describe information on the current status of microbiome research such as metagenomic code, salivary microbiome, pubic hair microbiome, microbes as indicators of body fluids, soils microbes as forensic indicator, and review microbial forensics as the feasibility of microbiome-based human identification.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.7
• /
• pp.1106-1112
• /
• 2007

This report provides the complete nucleotide sequences of the full-length cDNA encoding squalene synthase (SQS) and its genomic DNA sequence from a triterpene-producing fungus, Ganoderma lucidum. The cDNA of the squalene synthase (SQS) (GenBank Accession Number: DQ494674) was found to contain an open reading frame (ORF) of 1,404 bp encoding a 468-amino-acid polypeptide, whereas the SQS genomic DNA sequence (GenBank Accession Number: DQ494675) consisted of 1,984 bp and contained four exons and three introns. Only one gene copy was present in the G. lucidum genome. The deduced amino acid sequence of Ganoderma lucidum squalene synthase (GI-SQS) exhibited a high homology with other fungal squalene synthase genes and contained six conserved domains. A phylogenetic analysis revealed that G. lucidum SQS belonged to the fungi SQS group, and was more closely related to the SQS of U. maydis than to those of other fungi. A gene expression analysis showed that the expression level was relatively low in mycelia incubated for 12 days, increased after 14 to 20 days of incubation, and reached a relatively high level in the mushroom primordia. Functional complementation of GI-SQS in a SQS-deficient strain of Saccharomyces cerevisiae confirmed that the cloned cDNA encoded a squalene synthase.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.6
• /
• pp.608-618
• /
• 2000

We consider the problem of placing resources in a distributed computing system so that certain performance requirements may be met while minimizing the number of required resource copies, irrespective of node or link failures. To meet the requirements for high performance and high availability, minimum number of resource copies should be placed in such a way that each node has at least two copies on the node or its neighbor nodes. This is called the fault-tolerant resource placement problem in this paper. The structure of a parallel or a distributed computing system is represented by a graph. The fault-tolerant placement problem is first transformed into the problem of finding the smallest fault-tolerant dominating set in a graph. The dominating set problem is known to be NP-complete. In this paper, searching for the smallest fault-tolerant dominating set is formulated as a state-space search problem, which is then solved optimally with the well-known A* algorithm. To speed up the search, we derive heuristic information by analyzing the properties of fault-tolerant dominating sets. Some experimental results on various regular and random graphs show that the search time can be reduced dramatically using the heuristic information.

• Journal of Plant Biotechnology
• /
• v.44 no.2
• /
• pp.142-148
• /
• 2017

Drought stress is one of the important factors that restrict the expansion of Hevea brasiliensis cultivation to non-traditional regions experiencing extreme weather conditions. Plants respond to drought stress by triggering expression of several drought responsive genes including transcription factors which in turn trigger expression of various downstream signalling pathways and adaptive networks. Expression of such drought responsive genes may revert back to their original level upon re-watering. However, no reports are available on such phenomenon in Hevea and hence, this study was initiated. For this purpose, NAC transcription factor (NAC tf) was chosen as candidate gene. Its expression levels were monitored under intermittent drought as well as irrigated conditions in two clones (RRII 105 and RRIM 600) of H. brasiliensis with contrasting tolerance level. Copy number of NAC tf was found similar in both the clones. Expression of NAC tf was found highly up-regulated in RRIM 600 (a relatively drought tolerant clone) than in RRII 105 (a relatively drought susceptible clone) throughout the drought incidences which upon re-watering, reached back to its original levels in both the clones. The study indicated the existence of an association between expression of NAC tf and drought tolerance trait exhibited by the tolerant clone RRIM 600. The study also proves the influence of drought and re-watering on the leaf photosynthesis and expression of NAC tf in H. brasiliensis.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.81-88
• /
• 2007

The sprC gene encodes Streptomyces griseus protease C (SGPC), a bacterial chymotrypsin-like serine protease. Because the published data on sprC was not complete, we cloned and analyzed a new DNA fragment spanning downstream to upstream of the sprC gene from S. griseus IFO13350. The cloned 2.3-kb DNA fragment was placed on a high-copy number plasmid and introduced into Streptomyces lividans TK24. Chymotrypsin activity of the transformant was 8.5 times higher than that of the control after 3 days of cultivation and stably maintained until 9 days of cultivation, which dearly indicated that the cloned 2.3-kb fragment contained the entire sprC gene with its own promoter. When the same construct was introduced in the S. griseus IFO13350 (wild strain) and its two mutant strains in the A-factor regulatory cascade, ${\Delta}adpA$ and HO1, the chymotrypsin activity increased fivefold only in the ${\Delta}adpA$ strain. Transcriptional analysis based on RT-PCR revealed that the sprC gene is normally transcribed in both strains; however, earlier transcription was observed in the wild strain compared with the ${\Delta}adpA$ strain. A gel mobility shift assay showed that the AdpA protein did not bind to the promoter region of sprC. All these data clearly indicate that the expression of sprC is not dependent on the AdpA protein, but is distinctly regulated from other chymotrypsin genes composing an AdpA regulon. Earlier morphological differentiation was observed in S. lividans TK24, and S. griseus IFO13350 and HO1, transformed with the expression vector. The transformant of S. griseus ${\Delta}adpA$ formed markedly larger colonies. Antisense repression of sprC resulted in severe decrease of chymotrypsin activity, down to one-third of the control, and delayed morphological differentiation. All these data suggest that SGPC is related to normal morphogenesis in S. griseus.

• Korean Journal of Microbiology
• /
• v.47 no.3
• /
• pp.200-208
• /
• 2011

Most problematic antibiotic resistance mechanism for MLS (macrolide-lincosamide-streptogramn B) antibiotics encountered in clinical practice is mono- or dimethylation of specific adenine residue at 2058 (E. coli coordinate) of 23S rRNA which is performed by Erm (erythromycin ribosome resistance) protein through which bacterial ribosomes reduce the affinity to the antibiotics and become resistant to them. ErmSF is one of the four gene products produced by Streptomyces fradiae to be resistant to its own antibiotic, tylosin. Unlike other Erm proteins, ErmSF harbors idiosyncratic long N-terminal end region (NTER) 25% of which is comprised of arginine well known to interact with RNA. Furthermore, NTER was found to be important because when it was truncated, most of the enzyme activity was lost. Based on these facts, capability of NTER peptide to inhibit the enzymatic activity of ErmSF was sought. For this, expression system for two different proteins to be expressed in one cell was developed. In this system, two plasmids, pET23b and pACYC184 have unique replication origins to be compatible with each other in a cell. And expression system harboring promoter, ribosome binding site and transcription termination signal is identical but disparate amount of protein could be expressed according to the copy number of each vector, 15 for pACYC and 40 for pET23b. Expression of NTER peptide in pET23b together with ErmSF in pACYC 184 in E. coli successfully gave more amounts of NTER than ErmSF but no inhibitory effects were observed suggesting that there should be dynamicity in interaction between ErmSF and rRNA rather than simple and fixed binding to each other in methylation of 23S rRNA by ErmSF.

• Journal of Apiculture
• /
• v.34 no.1
• /
• pp.15-26
• /
• 2019

Tracheal mite (Acarapis woodi) is an internal parasite that is parasitic on the bronchus of adult bees and sucks fluid from the trachea. Since its first report by Rennie, it has been spread throughout Europe and in some Asian regions, with adjacent Japan and China reported in 2011 and 2012, respectively. Korea detected specific genes of A. woodi in 2015, but only one of 99 samples has been identified and the being of A. woodi has not been confirmed. In this study, we established a specific nested PCR method to confirm for detecting low-copy number of A. woodi-specific gene in bee samples. As a result, A. woodi-specific COI gene was amplified in 15 of 23 samples, and they were judged positive by melting point analysis and sequencing analysis. Although we could not observe the existence of the mites in bees, our results suggest that tracheal mit might exist in nature.