ISSN:
1617-4623
Keywords:
Microaerobiosis
;
cyd
;
arcA
;
fnr
;
Escherichia coli
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Transcriptional regulation of cyd, encoding the cytochrome d complex for O2 scavenging, was studied in Escherichia coli by monitoring ϕ(cyd-lac) expression under atmospheres containing 0–21% O2. Peak expression of this operon occurred under microaerobic conditions. Mutations in arcA (a trans-acting regulatory gene involved in aerobic respiration) greatly lowered ϕ(cyd-lac) expression under all conditions. Mutations in fnr (a trans-acting regulatory gene involved in anaerobic respiration) shifted the pattern of ϕ(cyd-lac) expression, lowering the microaerobic and aerobic expression. In an arcA fnr double mutant, ϕ(cyd-lac) expression became insignificant, irrespective of the availability of O2. It thus appears that the expression of the ϕ(cyd-lac) operon is under dual control by the two pleiotropic activators, ArcA and Fnr, which interact to give the peak microaerobic expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00273605
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