Details

Autor(en) / Beteiligte

• Popescu, Codrina V.
• Bates, Donna M.
• Beinert, Helmut
• Munck, Eckard
• Kiley, Patricia J.

Titel

Mossbauer Spectroscopy as a Tool for the Study of Activation/Inactivation of the Transcription Regulator FNR in Whole Cells of Escherichia coli

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 1998-11, Vol.95 (23), p.13431-13435

Ort / Verlag

United States: National Academy of Sciences of the United States of America

Erscheinungsjahr

1998

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• 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. Using57Fe 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 that57Fe 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.