Table 1.
Properties of Tar⋀ mutants
| Tar⋀ mutation† | Expression level‡ | Tar function§ | Dominance¶ | Epistasis‖ | Cluster formation†† | CW time‡‡ | Suppression by Tsr*§§ |
|---|---|---|---|---|---|---|---|
| V365F | 1.05 | 0.30 | 0.65 | 0.55 | 0.30 | 0.09 | + |
| G368D | 0.40 | 0.55 | 0.30 | 0.15 | 0.30 | 0.22 | na |
| L376F | 2.40 | 0.40 | 0.65 | 0.70 | 0.70 | 0.97 | − |
| A377T | 1.05 | 0.30 | 0.65 | 0.65 | 0.90 | 0.71 | − |
| A380V | 1.10 | 0.30 | 0.65 | 0.45 | 0.55 | 0.37 | + (F373W) |
| R386H | 2.95 | 0.45 | 0.50 | 0.80 | 0.40 | 0.61 | − |
| G388D | 2.80 | 0.30 | 0.65 | 0.50 | 0.85 | 0.04 | +(L380A) |
| E389G | 3.25 | 0.70 | 0.20 | 0.35 | 0.65 | 0.20 | na |
| G391S | 3.00 | 0.40 | 0.65 | 0.60 | nd | 0.55 | + |
| G393S | 0.35 | 0.40 | 0.45 | 0.40 | 0.40 | 0.88 | +(I377A) |
| G393V | 1.70 | 0.35 | 0.65 | 0.60 | 0.85 | 0.79 | − |
| V396A | 0.85 | 0.65 | 0.25 | 0.15 | 0.20 | 0.26 | na |
| V397A | 1.00 | 0.30 | 0.60 | 0.45 | 0.20 | 0.84 | − |
| V397M | 0.60 | 0.20 | 0.70 | 0.60 | 0.30 | 0.71 | − |
| E400K | 1.15 | 0.25 | 0.45 | 0.20 | 0.20 | 0.59 | − |
| V401M | 2.65 | 0.25 | 0.75 | 0.85 | 0.90 | 0.00 | − |
| A411T | 0.15 | 0.20 | 0.70 | 0.50 | 0.55 | 0.09 | − |
| A411V | 0.65 | 0.20 | 0.75 | 0.85 | 0.60 | 0.01 | − |
| E414K | 0.50 | 0.45 | 0.40 | 0.10 | 0.50 | 0.26 | na |
| WT | 1.00 | 1.00 | 0.00 | 0.00 | 1.00 | 0.28 | na |
Fractional data are rounded to the nearest 5% value. nd, not determined; na, not applicable.
†Tar residue numbers are two less than the corresponding Tsr residues, e.g., E400 of Tar corresponds to E402 of Tsr; mutations in italics are at trimer contact residues.
‡pLC113-Tar⋀/UU1250: fraction of WT Tar expression level.
§pLC113-Tar⋀/UU1250, T soft agar, 32.5°C, 10 hr: fraction of WT Tar colony diameter.
¶pLC113-Tar⋀/UU1624, T soft agar, 32.5°C, 10 hr: (1 − colony diameter normalized to WT).
‖pLC113-Tar⋀/UU1615, T soft agar, 32.5°C, 10 hr: (1 − colony diameter normalized to WT).
††pLC113-Tar⋀ + pPA789/UU1638: fraction of cells with one or more receptor clusters, normalized to WT Tar; 85% of Tar+ cells had clusters.
‡‡Fraction of time that tethered cells spent in CW rotation.
§§pLC113-Tar⋀ + pJC3-Tsr*/UU1250, T soft agar, 32.5°C, 10 hr. + indicates that the Tar defect was suppressed by the Tsr* partner(s) of the Tar⋀ mutation. When only one Tsr* partner suppressed the Tar⋀ defect, the suppressing mutation is shown in parentheses.