• Title/Summary/Keyword: DsbA

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Crystal Structure of DsbA from Corynebacterium diphtheriae and Its Functional Implications for CueP in Gram-Positive Bacteria

  • Um, Si-Hyeon;Kim, Jin-Sik;Song, Saemee;Kim, Nam Ah;Jeong, Seong Hoon;Ha, Nam-Chul
    • Molecules and Cells
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    • v.38 no.8
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    • pp.715-722
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    • 2015
  • In Gram-negative bacteria in the periplasmic space, the dimeric thioredoxin-fold protein DsbC isomerizes and reduces incorrect disulfide bonds of unfolded proteins, while the monomeric thioredoxin-fold protein DsbA introduces disulfide bonds in folding proteins. In the Gram-negative bacteria Salmonella enterica serovar Typhimurium, the reduced form of CueP scavenges the production of hydroxyl radicals in the copper-mediated Fenton reaction, and DsbC is responsible for keeping CueP in the reduced, active form. Some DsbA proteins fulfill the functions of DsbCs, which are not present in Gram-positive bacteria. In this study, we identified a DsbA homologous protein (CdDsbA) in the Corynebacterium diphtheriae genome and determined its crystal structure in the reduced condition at $1.5{\AA}$ resolution. CdDsbA consists of a monomeric thioredoxin-like fold with an inserted helical domain and unique N-terminal extended region. We confirmed that CdDsbA has disulfide bond somerase/reductase activity, and we present evidence that the N-terminal extended region is not required for this activity and folding of the core DsbA-like domain. Furthermore, we found that CdDsbA could reduce CueP from C. diphtheriae.

A Study on Implementation of 6 Channel DSB Modulator using DDS (DDS(Direct Digital Synthesis)를 이용한 6채널DSB(Double-SideBand) 변조기 구현에 관한 연구)

  • 하재승
    • Journal of the Korea Computer Industry Society
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    • v.2 no.8
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    • pp.1063-1068
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    • 2001
  • In this paper, we designed a high resolution six channel DSB modulator of Acousto-Optic effect generator make use of DDS technology. Also, configured seamless connection for other instruments to use IEEE-488 bus interface. We programmed the device driver for DDS and DAC control by 80C51 assembler language. And, high resolution 6 channel DSB modulator has improved the important characteristics of that the frequency tuning range, the resolution, the switching time. This DSB modulator system can use high precision frequency synthesizer for instruments.

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Phase Noise Characterization with Optical Carrier Suppression Level on Continuous Wave in the Ranges of Millimeter Waves Generated by Photomixing of Optical Double Sideband-Suppressed Carrier(DSB-SC) (광 반송파가 억압된 양측 대역 방식의 광 혼합을 통하여 발생된 밀리미터파 대역 연속파에서 광 반송파 억압 레벨에 따른 위상 잡음 특성 분석)

  • Kim, Sung-Il;Kang, Kwang-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.9
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    • pp.974-982
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    • 2009
  • Photomixing techniques beating two optical signals with different wavelengths and strong correlations are also very useful techniques to make a continuous wave(CW) signals in the range of millimeter(mm) and terahertz(THz) frequencies. An optical double sideband-suppressed carrier(DSB-SC) technique is one of the popular techniques to generate two optical signals with different wavelengths and strong correlations. DSB-SC signals with strong correlations are generated by a CW modulation of an optical carrier with a local oscillator and an optical modulator. In the previous parers related the DSB-SC for producing the CW signals within the range of mm and THz frequencies, there have been no reports why the optical carrier should suppress. In order to clear that, we have analyzed and measured the characteristics of the mm-wave CW signals made by the DSB-SC photomixing in this paper. From our analysis and measurement results, compared with the case of the DSB with the maximized optical carrier, the power and phase noise have improved about 23.9 dB and 21 dBc/Hz(@ 1 MHz offset frequency) in the case of the DSB with the minimized optical carrier (that is to say, the DSB-SC). Consequently, it is evident reason that the optical carrier should sufficiently suppress to obtain the mm-wave CW signals with the high power and low noise. This paper has given very helpful data to make mm- and THz-wave CW signals using photomixing techniques with the DSB-SC because the reason why the optical carrier should be suppressed is reported in this paper based on the numerical and experimental results.

Calculation for Components of Locational Marginal Price considering Demand-Side Bidding in a Competitive Electricity Market (경쟁시장내의 수요자원입찰을 고려한 모선별 한계가격의 구성요소산정 기법)

  • Kim, Hyun-Houng;Kim, Jin-Ho;Park, Jong-Bae;Shin, Joong-Rin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.7
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    • pp.1157-1166
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    • 2008
  • This paper presents a new approach for the evaluation of location marginal prices (LMPs) considering demand-side bidding (DSB) in a competitive electricity market. The stabilization of the electric power supply and demand balance is one of the major important activities in electric power industry. In this paper, we present an analytical method for calculation of LMPs considering DSB, which has opportunity to compete with generating units, as England & Wales Pool's DSB scheme[1]. Also, we propose a new approach that LMP considering DSB is divided into three components. The proposed approach can be used for the evaluation of demand-side bidding into the electricity market and the assessment of the influence of DSB on total production costs and LMPs as well as three components.

Ubiquitin E3 ligases in cancer: somatic mutation and amplification

  • Eun-Hye Jo;Mi-Yeon Kim;Hyung-Ju Lee;Hee-Sae Park
    • BMB Reports
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    • v.56 no.5
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    • pp.265-274
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    • 2023
  • Defects in DNA double-strand break (DSB) repair signaling permit cancer cells to accumulate genomic alterations that confer their aggressive phenotype. Nevertheless, tumors depend on residual DNA repair abilities to survive the DNA damage induced by genotoxic stress. This is why only isolated DNA repair signaling is inactivated in cancer cells. DNA DSB repair signaling contributes to general mechanism for various types of lesions in diverse cell cycle phases. DNA DSB repair genes are frequently mutated and amplified in cancer; however, limited data exist regarding the overall genomic prospect and functional result of these modifications. We list the DNA repair genes and related E3 ligases. Mutation and expression frequencies of these genes were analyzed in COSMIC and TCGA. The 11 genes with a high frequency of mutation differed between cancers, and mutations in many DNA DSB repair E3 ligase genes were related to a higher total mutation burden. DNA DSB repair E3 ligase genes are involved in tumor suppressive or oncogenic functions, such as RNF168 and FBXW7, by assisting the functionality of these genomic alterations. DNA damage response-related E3 ligases, such as RNF168, FBXW7, and HERC2, were generated with more than 10% mutation in several cancer cells. This study provides a broad list of candidate genes as potential biomarkers for genomic instability and novel therapeutic targets in cancer. As a DSB related proteins considerably appear the possibilities for targeting DNA repair defective tumors or hyperactive DNA repair tumors. Based on recent research, we describe the relationship between unstable DSB repairs and DSB-related E3 ligases.

Optical Millimeter-Wave Generation Based on DSB-SC Modulation (DSB-SC 변조에 의한 광 밀리미터파 신호 발생)

  • Choi, Jae-Won;Choi, Gyung-Sun;Seo, Dong-Sun;Jeon, Young-Min;Lee, Seok
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.11a
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    • pp.178-179
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    • 2002
  • We generate optical millimeter-waves by double-sideband suppressed carrier (DSB-SC) modulation using a Mach-Zehnder (MZ) modulator biased at the minimum power. The DSB-SC modulation allows the high-frequency intensity modulation for millimeter-wave generation at the twice of the MZ modulator driving frequency.

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Site Application Characteristics of Deep-Site Biopile System for Cleaning Oil-Contaminated Soil/Underground Water (유류오염 토양/지하수 정화를 위해 개발된 DSB(Deep-Site Biopile) System 현장적용특성)

  • Han Seung-Ho;Kong Sung-Ho;Kang Jung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.10 no.2
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    • pp.28-34
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    • 2005
  • The aim of this article is to assess the application characteristics of the site by remediating oil-contaminated area using DSB (Deep-site Biopile) system. In the contaminated area, the soil was composed of penetrable sand and the leaked oil was spread widely (total 7,201 cubic meters) through 2.5 meter deep underground water flow. DSB system was operated for 30 minutes intervals for 24 hours in a day (30 minutes opεration and 30 minutes stop). To check contamination level change in the contaminated area after DSB system was operated, samples were taken. The result from the site shows that BTEX/TPH contamination level was dropped 50% after 30-day operation of DSB system, and that contamination level was dropped below contamination level check standard after 165 days and the remediation was completed. Unlike traditional biological remediation methods DSB system could efficiently process soil and water which were contaminated by high levels of oil compounds.

Ku complex suppresses recombination in the absence of MRX activity during budding yeast meiosis

  • Yun, Hyeseon;Kim, Keunpil
    • BMB Reports
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    • v.52 no.10
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    • pp.607-612
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    • 2019
  • During meiosis, programmed double-strand breaks (DSBs) are repaired via recombination pathways that are required for faithful chromosomal segregation and genetic diversity. In meiotic progression, the non-homologous end joining (NHEJ) pathway is suppressed and instead meiotic recombination initiated by nucleolytic resection of DSB ends is the major pathway employed. This requires diverse recombinase proteins and regulatory factors involved in the formation of crossovers (COs) and non-crossovers (NCOs). In mitosis, spontaneous DSBs occurring at the G1 phase are predominantly repaired via NHEJ, mediating the joining of DNA ends. The Ku complex binds to these DSB ends, inhibiting additional DSB resection and mediating end joining with Dnl4, Lif1, and Nej1, which join the Ku complex and DSB ends. Here, we report the role of the Ku complex in DSB repair using a physical analysis of recombination in Saccharomyces cerevisiae during meiosis. We found that the Ku complex is not essential for meiotic progression, DSB formation, joint molecule formation, or CO/NCO formation during normal meiosis. Surprisingly, in the absence of the Ku complex and functional Mre11-Rad50-Xrs2 (MRX) complex, a large portion of meiotic DSBs was repaired via the recombination pathway to form COs and NCOs. Our data suggested that Ku complex prevents meiotic recombination in the elimination of MRX activity.

Evaluation of DNA Double Strand Breaks in Human and Mouse Lymphocyte Following ${\gamma}-Irradiation$ (${\gamma}-Ray$ 조사에 따른 사람의 정상임파구와 마우스 정상임파구의 DNA Double Strand Break 발생율에 대한 비교분석)

  • Kim Tae Hwan;Kim Sung Ho;Chung In Yong;Cho Chul Koo;Ko Kyung Hwan;Yoo Seong Yul
    • Radiation Oncology Journal
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    • v.11 no.2
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    • pp.219-225
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    • 1993
  • The evaluation of radiation-induced DNA double strand breaks (DSB) was made following irradiation of human lymphocytes, murine lymphocytes and EL-4 leukemia cells over a wide dose range of $^{60}Co\;{gamma}-rays.$ In lipopolysaccharide (LPS) or phytohemagglutinin (PHA)-stimulated murine lymphocytes, the slopes of the stand scission factor (SSF) revealed that lymphocytes with LPS increased DNA DSB formation by a factor of 1.432 (p<0.005). Furthermore, strand break production was relatively inefficient in the T lymphocytes compared to the B lymuhocytes. And EL-4 leukemia cells were found to form significantly more DNA DSB to a greater extent than normal lymphocytes (p<0.005). The in vitro studies of the intrinsic radiosensitivity between human lymphocytes and murine lymphocytes showed similar phasic kinetics. However, murine lymphocytes were lower in DNA DSB formation and higher in the relative radiation dose of 10 percent DNA strand breaks at 3.5 hours following ${gamma}-irradiation$ than human lymphocytes. Though it is difficult to interpret these results, these differences may be result from environmental and genetic factors. From our data, if complementary explanations for this difference will be proposed, the differences in the dose-effect relationship for the induction of DSB between humans and mice must be related to interspecies variations in the physiological condition of the peripheral blood in vitro and not to differences in the intrinsic radiation sensitivity of the lymphocytes. These results can be estimated on the basis of dose-effect correlation enabling the interpretation of clinical response and the radiobiological parameters of cytometrical assessment.

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A Study on the Low Temperature Growth of SiC Film with a 1,3-DSB Precursor (단일전구체(1,3-DSB)에 의한 저온 SiC박막 성장에 관한 연구)

  • 양재웅;노대호;윤진국;김재수
    • Journal of the Korean institute of surface engineering
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    • v.36 no.2
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    • pp.141-147
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    • 2003
  • Silicon carbide thin film was deposited in APCVD and LPCVD system with 1,3-DSB precursor 1,3-DSB is the single precursor to deposit SiC on Si at low temperature. SiC film was deposited at $850^{\circ}C$ lower than ordinary temperature ($1000~1200^{\circ}C$) in CVD process. SiC thin film glowed to high oriented (111) plane in APCVD system. In LPCVD system, SiC film groved to preferred (220) plane at same temperature. This discrepancy between preferred planes can be described by the difference of deposition mechanism. Amorphous phase and crystal defect were observed in APCVD system with the main growth mechanism of mass transport limited region. But in LPCVD system, we got the SIC film of uniform, faceted structure and high quality.