• Molecules and Cells
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• 제19권3호
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• pp.342-349
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• 2005

Cytokinins are adenine derivatives that regulate numerous plant growth and developmental processes, including apical and floral meristem development, stem growth, leaf senescence, apical dominance, and stress tolerance. However, not much is known about how cytokinin biosynthesis and metabolism is regulated. We identified a novel Arabidopsis gene, ALL, encoding an aldolase-like enzyme that regulates cytokinin signaling. An Arabidopsis mutant, all-1D, in which ALL is activated by the nearby insertion of the 35S enhancer, exhibited extreme dwarfism with rolled, dark-green leaves and reduced apical dominance, symptomatic of cytokinin-overproducing mutants. Consistent with this, ARR4 and ARR5, two representative primary cytokinin-responsive genes, were significantly induced in all-1D. Whereas SHOOT MERISTEMLESS (STM) and KNAT1, which regulate meristem development, were also greatly induced, expression of REV and PHV that regulate lateral organ polarity was inhibited. ALL encodes an aldolase-like enzyme that belongs to the HpcH/HpaI aldolase family in prokaryotes and is down-regulated by exogenous cytokinin, possibly through a negative feedback pathway. We propose that ALL is involved in cytokinin biosynthesis or metabolism and acts as a positive regulator of cytokinin signaling during shoot apical meristem development and determination of lateral organ polarity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권3호
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• pp.192-198
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• 2003

BiP, immunoglobulin binding protein, is an ER homologue of Hsp70. However, unlit other Hsp70 proteins, regulatory protein(s) for BiP has not been identified. Here, we demo strafed the presence of potential regulatory proteins for BiP using a pull -down assay. Since BiP can bind any unfolded protein, only the ATPase domain of BiP was used for the pull -down assay in order to minimize nonspecific binding. The ATPase domain was cloned to produce recombinant protein, which was then conjugated to CNBr-activated agarose. The structural conformation and ATP hydrolysis activity of the recombinant ATPase domain were similar to those of the native protein, light proteins from metabolically labeled mouse plasmacytoma cells specifically bound to the recombinant ATPase protein. The binding of these proteins was inhibited by excess amounts of free ATPase protein, and was dependent on the presence of ATP. These proteins were eluted by ADP. Of these proteins, Grp170 and BiP where identified. while the other were not identified as known ER proteins, from Western blot analyses. The presence of the ATPase-binding proteins for BiP was first demonstrated in this study, and our data suggest similar regulatory machinery for BiP may exist in the ER, as found in prokaryotes and other cellular compartments.

• 한국미생물·생명공학회지
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• 제50권3호
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• pp.404-413
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• 2022

The process of manufacturing craft beer involves a wide variety of spontaneous microorganisms, acting in different stages of the brewing process, that contribute to the distinctive characteristics of each style. The objective of this work was to compare the structure of microbial communities associated with two different craft beer styles (Doppelbock and Märzen lagers), at a late maturation stage, and to identify discriminative, or style-specific taxa. Bacterial and fungal microbial communities were analyzed by Illumina sequencing of 16S rRNA gene of prokaryotes and the ITS 2 spacer of fungi (eukaryotes). Fungal communities in maturating beer were dominated by the yeast Dekkera, and by lactic acid (Lactobacillus and Pediococcus) and acetic acid (Acetobacter) bacteria. The Doppelbock barrels presented more rich and diverse fungal communities. The Märzen barrels were more variable in terms of structure and composition of fungal and bacterial communities, with occurrence of exclusive taxa of fungi (Aspergillus sp.) and bacteria (L. kimchicus). Minority bacterial taxa, differently represented in the microbiome of each barrel, may underlie the variability between barrels and ultimately, the distinctive traits of each style. The composition of the microbial communities indicates that in addition to differences related to upstream stages of the brewing process, the contact with the wood barrels may contribute to the definition of style-specific microbiological traits.

• BMB Reports
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• 제57권1호
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• pp.40-49
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• 2024

Prokaryotes encode clustered regularly interspaced short palindromic repeat (CRISPR) arrays and CRISPR-associated (Cas) genes as an adaptive immune machinery. CRISPR-Cas systems effectively protect hosts from the invasion of foreign enemies, such as bacteriophages and plasmids. During a process called 'adaptation', non-self-nucleic acid fragments are acquired as spacers between repeats in the host CRISPR array, to establish immunological memory. The highly conserved Cas1-Cas2 complexes function as molecular recorders to integrate spacers in a time course manner, which can subsequently be expressed as crRNAs complexed with Cas effector proteins for the RNA-guided interference pathways. In some of the RNA-targeting type III systems, Cas1 proteins are fused with reverse transcriptase (RT), indicating that RT-Cas1-Cas2 complexes can acquire RNA transcripts for spacer acquisition. In this review, we summarize current studies that focus on the molecular structure and function of the RT-fused Cas1-Cas2 integrase, and its potential applications as a directional RNA-recording tool in cells. Furthermore, we highlight outstanding questions for RT-Cas1-Cas2 studies and future directions for RNA-recording CRISPR technologies.

• 한국토양비료학회지
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• 제49권1호
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• pp.17-29
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• 2016

Though there is an abundant supply of nitrogen in the atmosphere, it cannot be used directly by the biological systems since it has to be combined with the element hydrogen before their incorporation. This process of nitrogen fixation ($N_2$-fixation) may be accomplished either chemically or biologically. Between the two elements, biological nitrogen fixation (BNF) is a microbiological process that converts atmospheric di-nitrogen ($N_2$) into plant-usable form. In this review, the genetics and mechanism of nitrogen fixation including genes responsible for it, their types and role in BNF are discussed in detail. Nitrogen fixation in the different agricultural systems using different methods is discussed to understand the actual rather than the potential $N_2$-fixation procedure. The mechanism by which the diazotrophic bacteria improve plant growth apart from nitrogen fixation such as inhibition of plant ethylene synthesis, improvement of nutrient uptake, stress tolerance enhancement, solubilization of inorganic phosphate and mineralization of organic phosphate is also discussed. Role of diazotrophic bacteria in the enhancement of nitrogen fixation is also dealt with suitable examples. This mini review attempts to address the importance of diazotrophic bacteria in nitrogen fixation and plant growth improvement.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.986-993
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• 2001

Translation Initiation in prokaryotes involves the formation of a 30 S preinitiation complex, in which translation initiation factors play a role in the stimulation of fMet-tRNA (fMet) binding. However, the specific function and precise mechanism of initiation factor IF1 are still unclear. One a functionally active factor with a high purity. In the present study a large quantity of active IF was rapidly purified, obtained by the overexpression of the infA gene, and then used for a functional study. The induction of infA did not appreciably affect the growth rate of the protease-deficient strain E. coli AR68 harboring the IF1 overproducing plasmid. The level of IF1 obtained was approximately $1-2\%$ of the total cell protein, which enabled the yield of highly purified IF1 (>$98\%$ pure) to be increased to 0.15 mg of IF1/g of cells. The IF1 was isolated within one day by the centrifugatioin of the ribosomal washed fraction, by ammonium sulfate fractionation, chromatography on batch of phosphocellulose, and FPLC Mono S. The overexpressed IF1 was found to be comparable to the factor isolated from normal cells, as determined by migration in NEPHGE/SDS 2-D gels. For binding of fMet-tRNA(fMet) to the 30 S ribosomal subunitis, relatively high levels of binding were obtained when IF2 was present. The addition of IF1 up to 110 pmol proportionally stimulated the binding to a variable extent. This IF1-dependent stimulation of the 30 S preinitiation complex formation demonstrated that IF1 would appear to be exclusively essential for promoting the initiation phase of protein synthesis.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7523-7527
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• 2013

Thymidylate synthase (TS) catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. It is a primary target in the chemotherapy of colorectal cancers and some other neoplasms. In order to obtain pure protein for analysis of structure and biological function, an expression vector TS-pET28b (+) was constructed by inserting wild-type human thymidylate synthase (hTS) cDNA into pET28b (+). Then an expression strain was selected after transformation of the recombined plasmid into Rosetta (DE3). Fusion protein with His-tag was efficiently expressed in the form of inclusion bodies after IPTG induction and the content was approximately 40.0% of total bacteria proteins after optimizing expression conditions. When inclusion bodies were washed, dissolved and purified by Ni-NTA under denatured conditions, the purity was up to 90%. On SDS-PAGE and West-blotting, the protein band was found to match well with the predicted relative molecular mass-36kDa. Bioactivity was 0.1 U/mg. The results indicated that high-level expression of wild-type hTS cDNA can be achieved in prokaryotes with our novel method, facilitating research into related chemotherapy.

• ALGAE
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• 제17권1호
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• pp.59-68
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• 2002

A phylogenetic affinity between charophytes and embryophytes (land plants) has been explained by a few chloroplast genomic characters including gene and intron (Manhart and Palmer 1990; Baldauf et al. 1990; Lew and Manhart 1993). Here we show that a charophyte, Spirogyra maxima, has the largest operon of angiosperm chloroplast genomes, rpl23 operon (trnⅠ-rpl23-rpl2-rps19-rpl22-rps3-rpl16-rpl14-rps8-infA-rpl36-rps11-rpoA) containing both embryophyte introns, rpl16.i and rpl2.i. The rpl23 gene cluster of Spirogyra contains a distinct eubacterial promoter sequence upstream of rpl23, which is the first gene of the green algal rpl23 gene cluster. This sequence is completely absent in angiosperms but is present in non-flowering plants. The results imply that, in the rpl23 gene cluster, early charophytes had at least two promoters, one upstream of trnⅠ and and another upstream of rpl23, which partially or completely lost its function in land plants. A comparison of gene clusters of prokaryotes, algal chloroplast DNAs and land plant cpDNAs indicated a loss of numerous genes in chlorophyll a+b eukaryotes. A phylogenetic analysis using presence/absence of genes and introns as characters produced trees with a strongly supported clade containing chlorophyll a+b eukaryotes. Spirogyra and embryophytes formed a clade characterized by the loss of rpl5 and rps9 and the gain of trnⅠ (CAU) and introns in rpl2 and rpl16. The analyses support the hypothesis that the rpl23 gene cluster and the rpl2 and rpl16 introns of land plants originated from a common ancestor of Spirogyra and land plants.

• BMB Reports
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• 제44권11호
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• pp.719-724
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• 2011

The $Sec61{\alpha}$ subunit is the core subunit of the protein conducting channel which is required for protein translocation in eukaryotes and prokaryotes. In this study, we cloned a $Sec61{\alpha}$ subunit from Penicillium ochrochloron ($PoSec61{\alpha}$). Sequence and 3D structural model analysis showed that $PoSec61{\alpha}$ conserved the typical characteristics of eukaryotic and prokaryotic $Sec61{\alpha}$ subunit homologues. The pore ring known as the constriction point of the channel is formed by seven hydrophobic amino acids. Two methionine residues from transmembrane ${\alpha}$-helice 7 (TM7) contribute to the pore ring formation and projected notably to the pore area and narrowed the pore compared with the superposed residues at the corresponding positions in the crystal structures or the 3D models of the $Sec61{\alpha}$ subunit homologues in archaea or other eukaryotes, respectively. Results reported herein indicate that the pore ring residues differ among $Sec61{\alpha}$ subunit homologues and two hydrophobic residues in the TM7 contribute to the pore ring formation.

• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2019-2029
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• 2016

Zinc finger proteins are among the most extensively applied metalloproteins in the field of biotechnology owing to their unique structural and functional aspects as transcriptional and translational regulators. The classical zinc fingers are the largest family of zinc proteins and they provide critical roles in physiological systems from prokaryotes to eukaryotes. Two cysteine and two histidine residues ($Cys_2His_2$) coordinate to the zinc ion for the structural functions to generate a ${\beta}{\beta}{\alpha}$ fold, and this secondary structure supports specific interactions with their binding partners, including DNA, RNA, lipids, proteins, and small molecules. In this account, the structural similarity and differences of well-known $Cys_2His_2$-type zinc fingers such as zinc interaction factor 268 (ZIF268), transcription factor IIIA (TFIIIA), GAGA, and Ros will be explained. These proteins perform their specific roles in species from archaea to eukaryotes and they show significant structural similarity; however, their aligned amino acids present low sequence homology. These zinc finger proteins have different numbers of domains for their structural roles to maintain biological progress through transcriptional regulations from exogenous stresses. The superimposed structures of these finger domains provide interesting details when these fingers are applied to specific gene binding and editing. The structural information in this study will aid in the selection of unique types of zinc finger applications in vivo and in vitro approaches, because biophysical backgrounds including complex structures and binding affinities aid in the protein design area.