TABLE 4.

Some of the genes from clusters A and E that show substantial reduction in expression after the addition of ferrous sulfate

Category and protein	Proposed functions
Iron transport and storage
ChuABCD	Putative hemin uptake system
CfrA	Putative ferric siderophore receptor protein
Cj1661-1663 and Cj0173c-0175c	Putative ABC transporter systems
TonB3, ExbB2, ExbD2, TonB1, ExbB1, and ExbD1	Members of the three putative TonB-ExbB-ExbD energy-transducing complexes
p19 and Cj1658	Iron-regulated proteins with identity to components of iron transporters
Cj0177	Putative lipoprotein sharing homology with a protein involved in iron acquisition
CeuC	Putative enterobactin uptake permease
Cft	Ferritin
Cj0203, Cj0891c, Cj1163c, and Cj0339	Putative transmembrane tranporter proteins
Oxidative stress responses
PerR	Peroxide stress regulator
KatA	Catalase
AhpC	Alkyl hydroperoxide reductase
Tpx	Thiol peroxidase
SodB	Iron-containing superoxide dismutase
Iron not required as cofactor, physiologically important under iron-limited conditions?
Cj0414	Putative oxidoreductase
Cj0723c	Zinc metalloprotease involved in macromolecule degradation
PanC, PanB, BioC, MoaE, ThiC, NadE, TrxA, and TrxB	Cofactor biosynthesis
FldA	Flavodoxin
Cj0559	Oxidoreductase
Cj1287c	Malate oxidoreductase