Table 2.
Three phenotypic classes of RPS2 mutations that alter the accuracy of start codon recognition
| Near-cognate start |
Poor context AUG |
||||||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| RPS2 allele | Phenotype Class | Suppression of SUI5 His+ (Ssu−) | Suppression of SUI5 UUG/AUG | Suppression of SUI5 UUG/AUG | Reduced eIF1 expression | Increased SUI1opt-lacZ/SUI1-lacZ | Increased el.-uORF1-GCN4-lacZ |
| (Two UUG reporter) (Ssu−) | (One UUG reporter) (Ssu−) | ||||||
| D78A | II | Moderate | Strong | ND | No | No | No |
| Q89K | II | Strong | Strong | Very Strong | No | No | No |
| T90R | III | Weak | None | ND | No | Weak | Moderate |
| Q94D | III | Weak | None | Moderate | Yes | Strong | Strong |
| T96K | III | Weak | None | Moderate | Yes | Moderate | Strong |
| K119A | II | Moderate | Strong | Strong | No | No | No |
| V121D | I | ? | Strong | ND | Yes | No | Moderate |
| I125K | I | ? | Strong | ND | Yes | Weak | Strong |
?, suppression could not be evaluated because these mutations impaired growth in the presence of SUI5 on medium containing histidine.