Table 5.
Selected differentially expressed proteins with roles in iron metabolism or metabolism of other metals
| Protein name | Protein description | Avg relative abundancea |
Transcriptional regulator(s)b | Functional role(s) | ||
|---|---|---|---|---|---|---|
| In vitro | Ext | Int | ||||
| SitA | Fe/Mn transport periplasmic protein | 578 | 5,087 | 15,015 | Fur− | Fe and Mn import |
| FeoB | Ferrous iron transport protein B | 158 | 1,837 | 1,542 | Fnr+, ArcA+, Fur− | Ferrous iron import |
| IucA | Aerobactin biosynthesis | 0 | 45 | 502 | Fur− | Siderophore biosynthesis |
| IucB | Aerobactin biosynthesis | 0 | 648 | 2,556 | Fur− | Siderophore biosynthesis |
| IucC | Aerobactin biosynthesis | 0 | 48 | 308 | Fur− | Siderophore biosynthesis |
| IucD | Aerobactin biosynthesis | 0 | 517 | 2,744 | Fur− | Siderophore biosynthesis |
| IutA | Ferric aerobactin receptor | 34 | 419 | 6,042 | Fur− | Metal ion and siderophore import |
| FhuA | Ferrichrome outer membrane transporter | 0 | 96 | 306 | Fur− | Siderophore import |
| FhuC | Iron-hydroxamate transporter ATP-binding subunit | 0 | 66 | 276 | Fur− | Metal ion and siderophore import |
| ExbB | TonB energy transducing system subunit B | 0 | 1,659 | 508 | Fur− | Energy supply for siderophore and cofactor import |
| ExbD | TonB energy transducing system subunit D | 0 | 567 | 543 | Fur− | Energy supply for siderophore and cofactor import |
| CorA | Mn/Ni/Co transporter | 30 | 521 | 758 | Metal ion import and utilization | |
| TolC | Outer membrane channel protein TolC | 5,125 | 3,665 | 6,710 | PhoP+, SoxS− | Multidrug and siderophore efflux systems |
| IscU | Fe-S assembly scaffold protein IscU | 4,299 | 7,389 | 5,793 | IscR− | Fe-S cluster assembly |
| IscS | Cysteine desulfurase IscS | 848 | 1,918 | 1,393 | Crp+, Fis− | Fe-S cluster assembly |
| SufC | Cysteine desulfurase SufC | 0 | 201 | 1,829 | IhfB+, IscR+, OxyR+, Fur− | Fe-S cluster assembly under iron starvation and oxidative stress |
| SufB | Cysteine desulfurase activator complex subunit SufB | 0 | 76 | 306 | IhfB+, IscR+, OxyR+, Fur− | Fe-S cluster assembly under iron starvation and oxidative stress |
| SufA | Fe-S cluster assembly scaffold protein SufA | 0 | 55 | 661 | IhfB+, IscR+, OxyR+, Fur− | Fe-S cluster assembly under iron starvation and oxidative stress |
| Ftn | Ferritin | 25,840 | 15,482 | 4,031 | Fur+, H-NS− | Cytoplasmic iron storage |
a
Average relative APEXi protein abundance levels for in vitro-grown S. flexneri and for extracellular (Ext) and intracellular (Int) bacteria during coculture with Henle cells. More-detailed analyses are provided in Data Set S2 in the supplemental material.
b
Known or predicted transcriptional regulator(s) of the indicated gene, based on data for the closely related bacterium E. coli (www.ecocyc.org). +, positive regulation; −, negative regulation.