Table 2.
Ability of serine and aspartate-binding mutants of Tsr and Tar to support chemotaxis (swimming) and swarming motility
| Strain | Chemotaxis | Swarming |
|---|---|---|
| HCB429 | − | − |
| RP437 | ++++ | ++++ |
| HCB429/pJC3-Tsr | +++ | ++++ |
| /pJC3-Tsr(R64C) | − | +++++ |
| /pJC3-Tsr(T156P) | − | +++++ |
| /pNT201-Tar | ++ | +++ |
| /pNT201-Tar(R69K) | − | +++ |
| /pNT201-Tar(T154I) | − | ++++ |
| /pMK76-Tar(M76K) | ++ | +++ |
Chemotaxis assays were on swim (0.3%) agar plates, whereas swarming assays were on 0.45% agar plates, as described in Methods. Except for pMK76, protein expression from all plasmids was induced with 20 μM IPTG. Results are from several independent experiments. In any one experiment, the diameter of the swim/swarm colony after 16 h at 30°C was measured, and the results from four plates were averaged. Chemotaxis/swarming phenotype: −, no migration; +++, migration of ≈6 cm; ++++, migration of ≈8 cm (i.e., entire petri dish); +++++, migration of ≈8 cm after 12 h.