In Azotobacter vinelandii, the E1 subunit of the pyruvate dehydrogenase complex binds fpr promoter region DNA and ferredoxin I

被引:14
作者
Regnström, K [1 ]
Sauge-Merle, S [1 ]
Chen, K [1 ]
Burgess, BK [1 ]
机构
[1] Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA
关键词
D O I
10.1073/pnas.96.22.12389
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
In Azotobacter vinelandii, deletion of the fdxA gene that encodes a well characterized seven-iron ferredoxin (FdI) is known to lead to overexpression of the Fdf redox partner, NADPH:ferredoxin reductase (FPR). Previous studies have established that this is an oxidative stress response in which the fpr gene is transcriptionally activated to the same extent in response to either addition of the superoxide propagator paraquat to the cells or to fdxA deletion. In both cases, the activation occurs through a specific DNA sequence located upstream of the fpr gene. Here, we report the identification of the A. vinelandii protein that binds specifically to the paraquat activatable fpr promoter region as the El subunit of the pyruvate dehydrogenase complex (PDHE1), a central enzyme in aerobic respiration. Sequence analysis shows that PDHE1, which was not previously suspected to be a DNA-binding protein, has a helix-turn-helix motif. The data presented here further show that FdI binds specifically to the DNA-bound PDHE1.
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页码:12389 / 12393
页数:5
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