TABLE 3.
All five flagellin promoters are transcribed simultaneously in V. choleraea
Genotypeb | β-Galactosidase activity in strain with mutation:
|
||||
---|---|---|---|---|---|
flaAp-′lacZ | flaCp-′lacZ | flaEp-′lacZ | flaDp-′lacZ | flaBp-′lacZ | |
Wild type | 9,641 | 11,047 | 3,417 | 14,639 | 16,298 |
ΔflaA::Cmr | 11,063 | 13,789 | 6,833 | 11,341 | 15,833 |
ΔtoxR | 9,436 | 15,441 | 5,101 | 13,846 | 13,407 |
Assays were performed as described in Materials and Methods. Strains were grown in LB supplemented with 2 mM glutamine; cultures were assayed in triplicate at an optical density at 600 nm of ∼0.2 to 0.4. Results are the average of three samples expressed in Miller units (38). Each strain harboring the vector pRS551 alone grown in this medium has 10 to 15 Miller units of activity, which can be considered background activity.
The actual strains used (Table 1) were CG842 (wild type), KKV90 (ΔflaA::Cmr), and KKV62 (ΔtoxR), harboring plasmids pKEK80 (flaAp-′lacZ), pKEK76 (flaCp-′lacZ), pKEK81 (flaEp-′lacZ), pKEK77 (flaDp-′lacZ), and pKEK79 (flaBp-′lacZ).