• Title/Summary/Keyword: Nucleotide binding

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Cotton GhKCH2, a Plant-specific Kinesin, is Low-affinitive and Nucleotide-independent as Binding to Microtubule

  • Xu, Tao;Sun, Xuewei;Jiang, Shiling;Ren, Dongtao;Liu, Guoqin
    • BMB Reports
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    • v.40 no.5
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    • pp.723-730
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    • 2007
  • Kinesin is an ATP-driven microtubule motor protein that plays important roles in control of microtubule dynamics, intracellular transport, cell division and signal transduction. The kinesin superfamily is composed of numerous members that are classified into 14 subfamilies. Animal kinesins have been well characterized. In contrast, plant kinesins have not yet to be characterized adequately. Here, a novel plant-specific kinesin gene, GhKCH2, has been cloned from cotton (Gossypium hirsutum) fibers and biochemically identified by prokaryotic expression, affinity purification, ATPase activity assay and microtubule-binding analysis. The putative motor domain of GhKCH2, $M_{396-734}$ corresponding to amino acids Q396-N734 was fused with 6$\times$His-tag, soluble-expressed in E. coli and affinity-purified in a large amount. The biochemical analysis demonstrated that the basal ATPase activity of $M_{396-734}$ is not activated by $Ca^{2+}$, but stimulated 30-fold max by microtubules. The enzymatic activation is microtubule-concentration-dependent, and the concentration of microtubules that corresponds to half-maximum activation was about 11 ${\mu}M$, much higher than that of other kinesins reported. The cosedimentation assay indicated that $M_{396-734}$ could bind to microtubules in vitro whenever the nucleotide AMP-PNP is present or absent. As a plant-specific microtubule-dependent kinesin with a lower microtubule-affinity and a nucleotide-independent microtubule-binding ability, cotton GhKCH2 might be involved in the function of microtubules during the deposition of cellulose microfibrils in fibers or the formation of cell wall.

The Genetic Variations of NOD2 Are Associated With White Blood Cell Counts

  • Jin, Hyun-Seok;Park, Sangwook
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.334-340
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    • 2018
  • The cytoplasmic elicitor, nucleotide-binding domain and leucine-rich repeat containing domain receptors (NLRs) is well established molecules in its role in inflammatory response. Among 22 NLR receptors, NOD2 is one of the intensively studied genes of elucidating for the inflammatory bowel disease and Crohn's disease as well. Recent research have accumulated that common genetic mutations in Parkinson's disease (PD) are increasingly related to the susceptibility to Crohn's disease. In this study, with the Korean Genome and Epidemiology Study, we aimed to perform the association between NOD2 polymorphisms and blood cell counts [WBC (white blood cell) count, RBC (red blood cell) count, platelet count], which linked supposedly to cytoplasmic inflammatory responses with clinical specialty. Linear regression analyses were performed, controlling for residential area, sex, and age as covariates. As a results, 12 SNPs from NOD2 gene were significantly associated with WBC counts (Bonferroni correction P-value criteria < 0.05/23=0.00218). In this study, we could ensure an association with NOD2 gene and WBC counts. This is the first report to have relationship between SNPs of NOD2 gene and WBC counts.

Structural and Functional Analysis of Nitrogenase Fe Protein with MgADP bound and Amino Acid Substitutions (MgADP 결합 및 아미노산 치환 Nitrogenase Fe 단백질의 구조 및 기능 분석)

  • Jeong, Mi-Suk;Jang, Se-Bok
    • Journal of Life Science
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    • v.14 no.5
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    • pp.752-760
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    • 2004
  • The function of the [4Fe-4S] cluster containing iron (Fe-) protein in nitrogenase catalysis is to serve as the nucleotide-dependent electron donor to the MoFe protein which contains the sites for substrate binding and reduction. The ability of the Fe protein to function in this manner is dependent on its ability to adopt the appropriate conformation for productive interaction with the MoFe protein and on its ability to change redox potentials to provide the driving force required for electron transfer. The MgADP-bound (or off) conformational state of the nitrogenase Fe protein structure described reveals mechanisms for long-range communication from the nucleotide-binding sites to control affinity of association with the MoFe protein component. Two pathways, termed switches I and II, appear to be integral to this nucleotide signal transduction mechanism. In addition, the structure of the MgADP bound Fe protein provides the basis for the changes in the biophysical properties of the [4Fe-4S] observed when Fe protein binds nucleotides. The structures of the nitrogenase Fe protein with defined amino acid substitutions in the nucleotide dependent signal transduction pathways of the Switch I and Switch II have been determined by X-ray diffraction methods. These two pathways have been also implicated by site directed mutagenesis studies, structural analysis and analogies to other proteins that utilize similar nucleotide dependent signal transduction pathways. We have examined the validity of the assignment of these pathways in linking the signals generated by MgATP binding and hydrolysis to macromolecular complex formation and intermolecular electron transfer. The results provide a structural basis for the observed biophysical and biochemical properties of the Fe protein variants and interactions within the nitrogenase Fe protein-MoFe protein complex.

Nucleotide Polymorphisms of Cytochrome P450 Genes in Domestic Garlic Cultivars (국내 재배마늘의 Cytochrome P450 유전자의 염기다형성 분포)

  • Kwon, Soon-Tae;Chung, Jinbo
    • Korean Journal of Plant Resources
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    • v.31 no.5
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    • pp.531-537
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    • 2018
  • This study was carried to survey distribution of the nucleotide polymorphisms in heme-binding (HB) domain, which is highly conserved region between 1,210 and 1,240 bp of cytochrome P450, in domestic garlic cultivars. 120 garlic cultivars collected from Korea were classified into seven HB domain variation based on the nucleotide sequence of the domain. Northern type garlic cultivars, collected from Kyungpook, Chungnam, Chungpook and Kangwon province, showed 51.3% of KP2 type nucleotide sequence, 5'-TTT/GGC/GGT/GGA/CGG/AGA/ATA/TGT/CCT/GGA-3' with coding amino acid FGGGRRICPG, 13.7% of KP1, 11.3% of CP, 8.8% of CM and 5% of KW2 types. Southern type cultivars, collected from Kyungnam province, showed 52.5% of KM type nucleotide sequence, 5'-TTT/GGC/GCA/GGA/CGG/AGA/ATT/TGT/CCT/GGA-3' with coding amino acid FGAGRRICPG, 22.5% of KP2, 5.0% of KW2 and 2,5% of CP type nucleotide sequence. These results showed that Korean garlics were cultivated in highly mixed condition even in the same region.

Recognition of DNA Damage in Mammals

  • Lee, Suk-Hee
    • BMB Reports
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    • v.34 no.6
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    • pp.489-495
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    • 2001
  • DNA damage by UV and environmental agents are the major cause of genomic instability that needs to be repaired, otherwise it give rise to cancer. Accordingly, mammalian cells operate several DNA repair pathways that are not only responsible for identifying various types of DNA damage but also involved in removing DNA damage. In mammals, nucleotide excision repair (NER) machinery is responsible for most, if not all, of the bulky adducts caused by UV and chemical agents. Although most of the proteins involved in NER pathway have been identified, only recently have we begun to gain some insight into the mechanism by which proteins recognize damaged DNA. Binding of Xeroderma pigmentosum group C protein (XPC)-hHR23B complex to damaged DNA is the initial damage recognition step in NER, which leads to the recruitment of XPA and RPA to form a damage recognition complex. Formation of damage recognition complex not only stabilizes low affinity binding of XPA to the damaged DNA, but also induces structural distortion, both of which are likely necessary for the recruitment of TFIIH and two structure-specific endonucleases for dual incision.

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The Physical Interaction between Nucleotide-Binding Oligomerization Domain Containing 2 and Leucine-Rich Repeat Kinase 2

  • Jung, Ji-A;Park, Sangwook
    • Biomedical Science Letters
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    • v.26 no.1
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    • pp.47-50
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    • 2020
  • Recently, decades of robust researches on degenerative brain disorder have been highlighted on the interactive connection of gut and brain. In terms of inflammatory cytokine production, others have shown that Nucleotide-Binding Oligomerization Domain Containing 2 (NOD2) is involved with Leucine-Rich Repeat Kinase 2 (LRRK2). HEK293T cells were transiently co-transfected with Myc-tagged LRRK2 and Flag-tagged NOD2 and then followed by co-immunoprecipitation assay. In this study, we provide the novel finding of physical protein-protein interaction between NOD2 and LRRK2. G2019S variant has shown stronger interactions against NOD2 than those of wild type LRRK2. In an axis of NOD2-LRRK2 communication, it is believed to pave a new way in the understanding of the bidirectional molecular mechanism of brain disorder, including Parkinson's disease into gut inflammatory disease, including Crohn's disease.

Binding Symmetry of External Divalent Cations to Cyclic Nucleotide-gated IonChannel Reveled by Channel Tandem Dimers

  • Kwon, Ryuk-Jun;Park, Chul-Seung
    • Proceedings of the Korean Biophysical Society Conference
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    • 2001.06a
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    • pp.37-37
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    • 2001
  • Cyclic nucleotide-gated (CNG) channels are composed of homo or hetero tetramer of ${\alpha}$ and ${\beta}$ subunits. The a subunits of these channels have a conserved glutamate residue within the pore-forming region. This residue determines the selectivity as well as the affinity for the extracellular divalent cations. Using the high affinity mutant (E363D) of bovine retinal CNG channel in which the Glu was replaced to Asp at position 363, we constructed tandem dimers and investigated the binding symmetry of divalent cation to the site.(omitted)

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Functional Analysis of RAD4 Gene Required for Nucleotide Excision Repair of UV-induced DNA Damage in Saccharomyces cerevisiae

  • Park, Sang Dai;Park, In Soon
    • Animal cells and systems
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    • v.6 no.4
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    • pp.311-315
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    • 2002
  • The RAD4 gene is essential for nucleotide excision repair in Saccharomyces cerevisiae. It has been known that the deduced amino acid sequence of Rad4 protein contains three DNA-dependent ATPase/helicase motifs. To determine the biochemical activities and functional role of RAD4 the Rad4 protein was expressed and purified. Immunoblot analysis showed a specific band of 21 kDa, which was well-matched with the size of open reading frame of the RAD4 gene. The purified Rad4 protein had no detectable helicase activity. However, the protein could interact with double stranded oligonucleotides, as judged by mobility shift assay. This result suggests that the Rad4 protein is a DNA binding protein.

Molecular Cloning and Sequencing of Cell Wall Hydrolase Gene of an Alkalophilic Bacillus subtilis BL-29

  • Kim, Tae-Ho;Hong, Soon-Duck
    • Journal of Microbiology and Biotechnology
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    • v.7 no.4
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    • pp.223-228
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    • 1997
  • A DNA fragment containing the gene for cell wall hydrolase of alkalophilic Bacillus subtilis BL-29 was cloned into E. coli JM109 using pUC18 as a vector. A recombinant plasmid, designated pCWL45B, was contained in the fragment originating from the alkalophilic B. subtilis BL-29 chromosomal DNA by Southern hybridization analysis. The nucleotide sequence of a 1.6-kb HindIII fragment containing a cell wall hydrolase-encoding gene was determined. The nucleotide sequence revealed an open reading frame (ORF) of 900 bp with a concensus ribosome-binding site located 6 nucleotide upstream from the ATG start codon. The primary amino acid sequence deduced from the nucleotide sequence revealed a putative protein of 299 amino acid residues with an M.W. of 33, 206. Based on comparison of the amino acid sequence of the ORF with amino acid sequences in the GenBank data, it showed significant homology to the sequence of cell wall amidase of the PBSX bacteriophage of B. subtilis.

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Distinct Regional and Cellular Localization of Hyperpolarization-activated Cyclic Nucleotide-gated Channel 1 in Cerebellar Cortex of Rat

  • Kwon, Young-Joon;Kim, Tae-Sung
    • Journal of Korean Neurosurgical Society
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    • v.42 no.3
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    • pp.205-210
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    • 2007
  • Objective : Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediate the hyperpolarization-activated currents (Ih) that participate in regulating neuronal membrane potential and contribute critically to pacemaker activity, promoting synchronization of neuronal networks. However, distinct regional and cellular localization of HCN channels in the brain have not been precisely defined. Aim of this study was to verify the precise cellular location of HCN1 channels in rat cerebellum to better understand the physiological role these channels play in synaptic transmission between CNS neurons. Methods : HCN1 expression in rat brain was analyzed using immunohistochemistry and electron-microscopic observations. Postsynaptic density-95 (PSD-95), otherwise known as locating and clustering protein, was also examined to clarify its role in the subcellular location of HCN1 channels. In addition, to presume the binding of HCN1 channels with PSD-95, putative binding motifs in these channels were investigated using software-searching method. Results : HCN1 channels were locally distributed at the presynaptic terminal of basket cell and exactly corresponded with the location of PSD-95. Moreover, nine putative SH3 domain of PSD-95 binding motifs were discovered in HCN1 channels from motif analysis. Conclusion : Distinct localization of HCN1 channels in rat cerebellum is possible, especially when analyzed in conjunction with the SH3 domain of PSD-95. Considering that HCN1 channels contribute to spontaneous rhythmic action potentials, it is suggested that HCN1 channels located at the presynaptic terminal of neurons may play an important role in synaptic plasticity.