期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1998
卷号：95
期号：23
页码：13431-13435
DOI：10.1073/pnas.95.23.13431
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The global regulator FNR (for fumarate nitrate reduction) controls the transcription of >100 genes whose products facilitate adaptation of Escherichia coli to growth under O2-limiting conditions. Previous Mossbauer studies have shown that anaerobically purified FNR contains a [4Fe-4S]2+ cluster that, on exposure to oxygen, is converted into a [2Fe-2S]2+ cluster, a process that decreases DNA binding by FNR. Using 57Fe Mossbauer spectroscopy of E. coli cells containing overexpressed FNR, we show here that the same cluster conversion also occurs in vivo on exposure to O2. Furthermore, the data show that a significant amount of the [4Fe-4S]2+ cluster is regenerated when the cells are shifted back to an anaerobic environment. The present study also demonstrates that 57Fe Mossbauer spectroscopy can be employed to study the in vivo behavior of (overexpressed) proteins. The use of this technique to study other iron-containing cell components is discussed.
