Bowen S W, Hassan H M
Department of Food Science, North Carolina State University, Raleigh 27695-7624.
J Biol Chem. 1988 Oct 15;263(29):14808-11.
The synthesis of manganese-superoxide dismutase in response to hydrogen peroxide and to paraquat was examined in strains of Escherichia coli with different mutations in the oxyR gene. Hydrogen peroxide treatment did not induce manganese-superoxide dismutase, but did induce the oxyR regulon. Paraquat induced this enzyme in a strain compromised in its ability to induce the defense response against oxidative stress (oxyR deletion) as well as in a strain that is constitutive and overexpresses the oxyR regulon. Catalase (HPI), but not manganese-superoxide dismutase, was over-expressed under anaerobic conditions in a strain harboring a constitutive oxyR mutation. The data clearly demonstrate that the induction of manganese-superoxide dismutase is independent of the oxyR-controlled regulon.
在氧还调节基因（oxyR）存在不同突变的大肠杆菌菌株中，研究了过氧化氢和百草枯对锰超氧化物歧化酶合成的影响。过氧化氢处理不会诱导锰超氧化物歧化酶的产生，但会诱导氧还调节基因操纵子。百草枯在诱导针对氧化应激的防御反应能力受损的菌株（氧还调节基因缺失）以及组成型且过表达氧还调节基因操纵子的菌株中均可诱导该酶的产生。在携带组成型氧还调节基因突变的菌株中，过氧化氢酶（HPI）而非锰超氧化物歧化酶在厌氧条件下过表达。数据清楚地表明，锰超氧化物歧化酶的诱导独立于氧还调节基因控制的操纵子。
