TABLE 3.
Effect of polyamine addition to an E. coli mutant lacking polyamines on the expression of genes in the acid fitness island and other acid response pathways and the relative roles of rpoS and gadE gene deletions
| Gene names | Functions | Fold change in gene expression (after addition of polyamines)a |
||
|---|---|---|---|---|
| rpoS+/gadE+ | ΔrpoS/gadE+ | ΔgadE/rpoS+ | ||
| gadB | Glutamate decarboxylase B | 25.9 | 8.2 | 8 |
| gadA | Glutamate decarboxylase A | 20.7 | 3 | 3 |
| gadE | Regulator of GDAR | 8.6 | 3 | |
| hdeD | Acid resistance, putative membrane transporter | 7.2 | 3 | 2.2 |
| slp | Acid resistance, outer membrane lipoprotein | 6.8 | 4 | 6 |
| dctR | Putative LuxR family repressor for C4-dicarboxylate transporter | 6 | 2 | 6.9 |
| yhiD | Predicted Mg2+ transport ATPase | 5.4 | 2 | 3.8 |
| gadC | Antiporter GABA/glutamate | 4.8 | 3 | 1.4 |
| mdtF | Anaerobic multidrug efflux transporter | 3.9 | 2 | −1.8 |
| hdeA | Periplasmic chaperone of acid denatured proteins | 3.8 | 3 | 2.3 |
| yhiU | Anaerobic multidrug efflux transporter | 2.3 | 1 | −1.7 |
| gadX | Regulator of GDAR | 1.9 | 2 | 2 |
| gadY | Small RNA regulator of GDAR | 1.9 | 1 | 2.1 |
| hdeB | Periplasmic chaperone of acid-denatured proteins | 1.7 | 2 | 1.8 |
| rpoS | Sigma factor (σ38) for RNA polymerase | 1.2 | 1.3 | |
a The data are averages of three independent microarray experiments using Affymetrix E. coli chip 2.0 (p < 0.05). The data presented for rpoS+/gadE+ strain in this table are from the microarray experiments comparing rpoS+/gadE+ and ΔgadE/rpoS+ cultures. The complete microarray data are available as supplemental Data Sets S1 and S2. Functional annotations are based on the Ecogene Database.