• 제목/요약/키워드: Molecular Biology

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Crystal structure of the pretense domain of an ATP-independent heat shock protease HtrA

  • Kim, Dong-Young;Kim, Dong-Ryoung;Ha, Sung-Chul;Neratur K.Lokanath;Hwang, Hye-Yeon;Kim, Kyeong-Kyu
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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    • pp.24-24
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    • 2002
  • HtrA (high temperature requirement A), a periplasmic heat shock protein, is known to have molecular chaperone function at low temperatures and proteolytic activity at elevated temperatures. To investigate the mechanism of functional switch to pretense, we have determined the crystal structure of the N-terminal protease domain (PD) of HtrA from Thermotoga maritima. HtrA PD shares the same fold with chymotrypsin-like serine professes. However, crystal structure suggests that HtrA PD is not an active pretense at current state since its active site is not formed properly and blocked by an additional helical lid. On the surface of the lid, HtrA PD has hydrophobic patches that could be potential substrate binding sites for molecular chaperone activity. Present structure suggests that the activation of the proteolytic function of HtrA PD at elevated temperatures might occur by the conformational change.

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The subcellular distribution of MnSOD alters during sodium selenite-induced apoptosis

  • Guan, Liying;Jiang, Qian;Li, Zhushi;Huang, Fang;Ren, Yun;Yang, Yang;Xu, Caimin
    • BMB Reports
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    • 제42권6호
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    • pp.361-366
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    • 2009
  • It was reported that high doses of sodium selenite can induce apoptosis of cancer cells, but the molecular mechanisms are poorly understood. Manganese superoxide dismutase (MnSOD) converts superoxide radical to hydrogen peroxide within the mitochondrial matrix and is one of the most important antioxidant enzymes. In this study, we showed that 20 ${\mu}M$ sodium selenite could alter subcellular distribution of MnSOD, namely a decrease in mitochondria and an increase in cytosol. The alteration of subcellular distribution of MnSOD is dependent on the production of superoxide induced by sodium selenite.