Table 4.
Suppressing Mutations of H protein defects.
| Strain b | Independent Isolations c |
EOP a | ||
|---|---|---|---|---|
| 22 °C | 33/37 °C | 42 °C | ||
| Wild Type | NA d | 0.2 | 1.0 | 0.7 |
| cs(H)T244Q | NA | 4.8 × 10−2 | 1.0 | 1.0 |
| su(H)-F H73Y/cs(H)T244Q | 2 | 0.3 | 1.0 | 1.2 |
| su(H)-F Y158H/cs(H)T244Q | 3 | 0.2 | 1.0 | 0.7 |
| su(H)-F T204I/cs(H)T244Q | 1 | 0.2 | 1.0 | 1.3 |
| su(H)-F M330I/cs(H)T244Q | 1 | 0.3 | 1.0 | 0.9 |
| su(H)-F R386H/cs(H)T244Q | 1 | 0.3 | 1.0 | 0.9 |
| su(H)-H R185H/cs(H)T244Q | 1 | 1.0 | <6.4 × 10−5 | <6.4 × 10−5 |
| su(H)-H A194S/cs(H)T244Q | 1 | 0.2 | 1.0 | 1.0 |
| cs(H)M251Q | NA | 2.6 × 10−2 | 1.0 | 1.0 |
| su(H)-F T100A/cs(H)M251Q | 1 | 0.1 | 1.0 | 1.6 |
| su(H)-F Y158H/cs(H)M251Q | 1 | 0.3 | 1.0 | 1.2 |
| su(H)-F T204I/cs(H)M251Q | 1 | 0.2 | 1.0 | 1.1 |
| su(H)-F L319F/cs(H)M251Q | 1 | 0.1 | 1.0 | 0.6 |
| su(H)-F M330I/cs(H)M251Q | 2 | 0.3 | 1.0 | 0.8 |
| su(H)-F V333F/cs(H)M251Q | 1 | 0.1 | 1.0 | 1.2 |
| su(H)-F R386H/cs(H)M251Q | 1 | 0.1 | 1.0 | 0.7 |
| su(H)-H E197D/cs(H)M251Q | 1 | 0.4 | 1.0 | 1.1 |
| su(H)-H M198V/cs(H)M251Q | 1 | 0.5 | 1.0 | 0.9 |
| cs(H)T244Q/M251Q | NA | <9.5 × 10−6 | 1.0 | 1.2 |
| su(H)-H M198I/cs(H)T244Q/M251Q | 1 | 0.1 | 1.0 | 1.2 |
| su(H)-H M198V/cs(H)T244Q/M251Q | 2 | 0.2 | 1.0 | 0.9 |
| su(H)-F T204I/cs(H)T244Q/M251Q | SD d | <1.9 × 10−3 | 1.0 | <1.9 × 10−3 |
| su(H)-F M330I/cs(H)T244Q/M251Q | SD d | <6.9 × 10−6 | 1.0 | 0.5 |
| su(H)-F R386H/cs(H)T244Q/M251Q | SD d | <6.0 × 10−6 | 1.0 | 1.0 |
| cs|ts(H)Q241S/Q247S | NA | <2.5 × 10−4 | 1.0 | <2.5 × 10−4 |
| su(H)-H N216D/cs|ts(H)Q241S/Q247S | 1 | <0.2 | 1.0 | 0.8 |
| su(H)-H T234I/cs|ts(H)Q241S/Q247S | 2 | <0.05 | 1.0 | 0.9 |
| su(H)-H A239V/cs|ts(H)Q241S/Q247S | 1 | <1.8 × 10−5 | 1.0 | 0.3 |
| su(H)-H Q235K/cs|ts(H)Q241S/Q247S | 1 | <0.2 | 1.0 | 2.2 |
| su(H)-H F243L/cs|ts(H)Q241S/Q247S | 3 | <8.0 × 10−4 | 1.0 | 0.6 |
| su(H)-H Q247L/cs|ts(H)Q241S/Q247S | 8 | <1.0 × 10−4 | 1.0 | 1.2 |
| su(H)-H V255I/cs|ts(H)Q241S/Q247S | 1 | <2.0 × 10−3 | 1.0 | 0.5 |
a Efficiency of plating. Values are normalized to those obtained at 37 °C for cs mutants, and at 33 °C for cs|ts mutants. b Suppressing mutations are named with the gene in which the nucleotide substitution was found and the resulting amino acid change. Thus, su(H)-F H73Y indicates a suppressor of an H defect in gene F, conferring an H73Y substitution at amino acid 73. c For cs mutants, revertant plaques were picked from plates incubated at 22 °C. For cs|ts mutants, revertant plaques were picked from plates incubated at 42 °C. d NA: not applicable, parental strain.