Dual functions of Arabidopsis sulfiredoxin: acting as a redox-dependent sulfinic acid reductase and as a redox-independent nuclease enzyme.

Yong Hun Chi, Sun Young Kim, In Jung Jung, Mi Rim Shin, Young Jun Jung, Jin Ho Park, Eun Seon Lee, Punyakishore Maibam, Kang-San Kim, Joung Hun Park, Min Ji Kim, Gwang Yong Hwang, Sang Yeol Lee

Division of Applied Life Science (BK21 Program) and PMBBRC, Gyeongsang National University, Jinju, Republic of Korea.

FEBS letters 2012 Sep 21

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Based on the fact that the amino acid sequence of sulfiredoxin (Srx), already known as a redox-dependent sulfinic acid reductase, showed a high sequence homology with that of ParB, a nuclease enzyme, we examined the nucleic acid binding and hydrolyzing activity of the recombinant Srx in Arabidopsis (AtSrx). We found that AtSrx functions as a nuclease enzyme that can use single-stranded and double-stranded DNAs as substrates. The nuclease activity was enhanced by divalent cations. Particularly, by point-mutating the active site of sulfinate reductase, Cys (72) to Ser (AtSrx-C72S), we demonstrate that the active site of the reductase function of AtSrx is not involved in its nuclease function. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Citation

Yong Hun Chi, Sun Young Kim, In Jung Jung, Mi Rim Shin, Young Jun Jung, Jin Ho Park, Eun Seon Lee, Punyakishore Maibam, Kang-San Kim, Joung Hun Park, Min Ji Kim, Gwang Yong Hwang, Sang Yeol Lee. Dual functions of Arabidopsis sulfiredoxin: acting as a redox-dependent sulfinic acid reductase and as a redox-independent nuclease enzyme. FEBS letters. 2012 Sep 21;586(19):3493-9