SCI和EI收录∣中国化工学会会刊

›› 2012, Vol. 20 ›› Issue (1): 52-61.

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Structural Basis for the Thermostability of Sulfur Oxygenase Reductases

尤晓颜1, 孟珍2, 陈栋炜1, 郭旭1, Josef Zeyer3, 刘双江1, 姜成英1   

  1. 1. State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
    2. Scientific Data Center, Computer Network Information Center, Chinese Academy of Sciences, Beijing 100190, China;
    3. Environmental Microbiology, Institute for Biogeochemistry and Pollutant Dynamics(IBP), Federal Institute of Technology(ETH), Switzerland
  • 收稿日期:2011-10-08 修回日期:2011-12-19 出版日期:2012-02-28 发布日期:2012-05-03
  • 通讯作者: LIU Shuangjiang,E-mail:liusj@sun.im.ac.cn;JIANG Chengying,E-mail:jiangcy@im.ac.cn
  • 基金资助:
    Supported by the National Natural Science Foundation of China (31070042,30870039,30921065);partially by Open Funding Project of the National Key Laboratory of Biochemical Engineering,China (2010KF-2)

Structural Basis for the Thermostability of Sulfur Oxygenase Reductases

YOU Xiaoyan1, MENG Zhen2, CHEN Dongwei1, GUO Xu1, Josef Zeyer3, LIU Shuangjiang1, JIANG Chengying1   

  1. 1. State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
    2. Scientific Data Center, Computer Network Information Center, Chinese Academy of Sciences, Beijing 100190, China;
    3. Environmental Microbiology, Institute for Biogeochemistry and Pollutant Dynamics(IBP), Federal Institute of Technology(ETH), Switzerland
  • Received:2011-10-08 Revised:2011-12-19 Online:2012-02-28 Published:2012-05-03
  • Supported by:
    Supported by the National Natural Science Foundation of China (31070042,30870039,30921065);partially by Open Funding Project of the National Key Laboratory of Biochemical Engineering,China (2010KF-2)

摘要: The thermostability of three sulfur oxygenase reductases(SORs) was investigated from thermoacidophilic achaea Acidianus tengchongensis(SORAT) and Sulfolobus tokodaii(SORST) as well as the moderately thermophilic bacterium Acidithiobacillus sp.SM-1(SORSB).The optimal temperatures for catalyzing sulfur oxidation were 80℃(SORAT),85℃(SORST),and 70(SORSB),respectively.The half-lives of the three SORs at their optimal catalytic conditions were 100 min(SORAT),58 min(SORST),and 37 min(SORSB).In order to reveal the structural basis of the thermostability of these SORs,three-dimensional structural models of them were generated by homology modeling using the previously reported high-resolution X-ray structure of SORAA(from Acidianus ambivalens) as a template.The results suggest that thermostability was dependent on:(a) high number of the charged amino acid glutamic acid and the flexible amino acid proline,(b) low number of the thermolabile amino acid glutamine,(c) increased number of ion pairs,(d) decreased ratio of hydrophobic accessible solvent surface area(ASA) to charged ASA,and(e) increased volumes of the cavity.The number of cavities and the number of hydrogen bonds did not significantly affect the thermostability of SORs,whereas the cavity volumes increased as the thermal stability increased.

关键词: sulfur oxygenase reductase(SOR), thermostability, homology modeling, Acidianus,Sulfolobus,Acid-ithiobacillus

Abstract: The thermostability of three sulfur oxygenase reductases(SORs) was investigated from thermoacidophilic achaea Acidianus tengchongensis(SORAT) and Sulfolobus tokodaii(SORST) as well as the moderately thermophilic bacterium Acidithiobacillus sp.SM-1(SORSB).The optimal temperatures for catalyzing sulfur oxidation were 80℃(SORAT),85℃(SORST),and 70(SORSB),respectively.The half-lives of the three SORs at their optimal catalytic conditions were 100 min(SORAT),58 min(SORST),and 37 min(SORSB).In order to reveal the structural basis of the thermostability of these SORs,three-dimensional structural models of them were generated by homology modeling using the previously reported high-resolution X-ray structure of SORAA(from Acidianus ambivalens) as a template.The results suggest that thermostability was dependent on:(a) high number of the charged amino acid glutamic acid and the flexible amino acid proline,(b) low number of the thermolabile amino acid glutamine,(c) increased number of ion pairs,(d) decreased ratio of hydrophobic accessible solvent surface area(ASA) to charged ASA,and(e) increased volumes of the cavity.The number of cavities and the number of hydrogen bonds did not significantly affect the thermostability of SORs,whereas the cavity volumes increased as the thermal stability increased.

Key words: sulfur oxygenase reductase(SOR), thermostability, homology modeling, Acidianus,Sulfolobus,Acid-ithiobacillus

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