Table II. Properties of spt16 mutants.
| Change in MPT (°C) when combined with a second mutation | |||||
|---|---|---|---|---|---|
| spt16 allele | MPT (°C) | pob3-L78R | nhp6-Δ | dna2-2 | ctf18-Δ |
| SPT16 | >37 | 0 | 0 | 0 | 0 |
| spt16-G132D | 34 | –3 | –1 | –2 | –2 |
| spt16-6 | 33.5 | SL | –3.5 | –2.5 | –2.5 |
| spt16-7 | 34 | SL | –3 | –1 | –2 |
| spt16-8 | 35.5 | SL | –3.5 | –3.5 | –2 |
| spt16-9 | 32 | SL | –2 | –2 | –2 |
| spt16-9a | >37 | 0 | |||
| spt16-11 | 34.5 | SL | –5.5 | –2.5 | –2.5 |
| spt16-16 | 36.5 | SL | SL | SL | –2.5 |
| spt16-16a | <37 | SL | |||
| spt16-24 | 37 | SL | –6 | –3 | –3 |
7737-3-2 (spt16-Δ) with pTF128 (SPT16-WT) or derivatives with the alleles shown were used to test the MPT. Congenic strains 7810-4-3 (spt16-Δ pob3-L78R), 7847-2-4 (spt16-Δ, nhp6a-Δ, nhp6b-Δ), 7800-3-2 (spt16-Δ, dna2-2) and 7806-2-3 (spt16-Δ, ctf18-Δ) carrying the same SPT16 alleles on plasmids were also tested and the difference between the MPT for the double mutant and the MPT for the single mutant with the lower restrictive temperature is shown. SL indicates that the combination was synthetically lethal.