Open AccessThe effect of iron limitation on expression of the aerobic and anaerobic electron transport pathway genes in Escherichia coli
Author(s) -
Cotter Peggy A.,
Darie Silvia,
Gunsalus Robert P.
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb14045.x
Subject(s) - lac operon , operon , escherichia coli , anaerobic exercise , biology , gene , gene expression , anaerobic respiration , microbiology and biotechnology , biochemistry , physiology
To determine whether the aerobic and anaerobic respiratory pathways of Escherichia coli are regulated in response to iron availability, strains containing lacZ reporter fusions to the cydAB , cyoABCDE, narGHJI, dmsABC and frdABCD operons were grown in medium limited for iron by use of the chelator, 2,2′‐dipyridyl. Under anaerobic conditions, expression of the anaerobic respiratory pathway operons, narG‐lacZ, dmsA‐lacZ and frdA‐lacZ , was reduced 14–16 fold when iron was limited. In contrast, expression of the aerobic pathway operons, cyoA‐lacZ and cydA‐lacZ , was elevated modestly. Iron‐dependent transcriptional control of these operons was independent of the fur gene which encodes an iron‐and‐DNA‐binding regulatory protein. The expression of fnr‐lacZ was relatively unaffected by iron limitation suggesting that Fnr levels in the cell do not change in response to iron. The above findings suggest that in addition to Fur, some other cellular protein may bind iron for reporting and regulating iron‐dependent cell functions.