Abstract
Expression of the lacZ gene from the Fnr-regulated FF-melR promoter on a plasmid in iron-deprived Paracoccus denitrificans cells required not only a decreased oxygen tension but also supplementation with iron. The levels of beta-galactosidase and 5-aminolevulinate synthase showed comparable responses to changes in iron availability. The presence of soluble and particulate enzymes catalyzing the reduction of Fe(III) by NADH suggests a hypothesis in which the redox state of the cytoplasmic NAD-couple determines the concentration of free Fe(II) and thereby modulates the activity of a common regulator of the Fnr type.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
5-Aminolevulinate Synthetase / genetics
-
5-Aminolevulinate Synthetase / metabolism
-
Bacterial Proteins / pharmacology*
-
Escherichia coli Proteins*
-
Ferric Compounds / metabolism
-
Ferrous Compounds / metabolism
-
Gene Expression / drug effects
-
Iron / metabolism*
-
Iron / pharmacology
-
Iron-Sulfur Proteins / pharmacology*
-
NAD / metabolism
-
Oxidation-Reduction
-
Oxygen / pharmacology*
-
Paracoccus denitrificans / genetics
-
Paracoccus denitrificans / metabolism*
-
Transcription Factors / pharmacology
-
beta-Galactosidase / genetics
-
beta-Galactosidase / metabolism
Substances
-
Bacterial Proteins
-
Escherichia coli Proteins
-
FNR protein, E coli
-
Ferric Compounds
-
Ferrous Compounds
-
Iron-Sulfur Proteins
-
Transcription Factors
-
NAD
-
Iron
-
5-Aminolevulinate Synthetase
-
beta-Galactosidase
-
Oxygen