Levén S, Heimberger A, Eisenstark A
Division of Biological Sciences, University of Missouri, Columbia 65211.
Biochem Biophys Res Commun. 1990 Sep 28;171(3):1224-8. doi: 10.1016/0006-291x(90)90816-6.
The katG gene in Escherichia coli encodes catalase HPI, which is involved in membrane transport and protects the cell during oxidative stress. Hydrogen peroxide (H2O2) induces synthesis of HPI. We examined the role of HPI in membrane permeability (proline uptake) following exposure to near-ultraviolet radiation (NUV). We found that NUV resulted in the same type of induction as H2O2. KatG::Tn10 cells experienced a large drop in uptake after NUV exposure, and levels remained low following incubation. A strain carrying a katG+ plasmid, however, showed considerably less decrease in uptake after NUV, and uptake quickly resumed upon incubation. Further, in an srd mutant which lacks 4-thiouracil, NUV resulted in only a small drop in proline uptake, which was immediately resumed.
大肠杆菌中的katG基因编码过氧化氢酶HPI，它参与膜运输并在氧化应激期间保护细胞。过氧化氢（H2O2）可诱导HPI的合成。我们研究了HPI在暴露于近紫外辐射（NUV）后对膜通透性（脯氨酸摄取）的作用。我们发现NUV导致与H2O2相同类型的诱导。KatG::Tn10细胞在暴露于NUV后摄取量大幅下降，孵育后水平仍保持较低。然而，携带katG+质粒的菌株在暴露于NUV后摄取量的下降要小得多，并且在孵育后摄取迅速恢复。此外，在缺乏4-硫尿嘧啶的srd突变体中，NUV仅导致脯氨酸摄取量小幅下降，随后立即恢复。
