Scavenging reactive oxygen species by rice dehydroascorbate reductase alleviates oxidative stresses in Escherichia coli.
Maintaining redox balance is one of the crucial requirements for a cell to endure stress from the outside. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) plays an important role in the ascorbate-glutathione cycle; one of the major ROS scavenging systems in most known biological systems. A cDNA clone of the DHAR gene from Oryza sativa (OsDHAR) was isolated and overexpressed in Escherichia coli BL21 (DE3) strain from the pET-28a(+) expression vector. The OsDHAR transformed E. coli cells showed significantly higher DHAR activity and a lower level of ROS than the E. coli cells transformed by an empty pET-28a(+) vector. Also, the DHAR-overexpressing E. coli strain was more tolerant to oxidant- and heavy metal-mediated stress conditions than the control E. coli strain. The results suggest that the overexpressed rice DHAR gene effectively functions in a prokaryotic system and provide protection to various oxidative stresses.
Shin
Sun-Young
SY
Department of Biology, Kyungpook National University, Daegu 702-701, Korea.
Kim
Il-Sup
IS
Kim
Yul-Ho
YH
Park
Hyang-Mi
HM
Lee
Jang-Yong
JY
Kang
Hong-Gyu
HG
Yoon
Ho-Sung
HS
D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology*; D018384:Oxidative Stress / Q000235:genetics*; D010088:Oxidoreductases / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate)