Table 3.
SUP45 alleles used in this study
| SUP45 mutant | Amino acid distance scorea | Published allele name | Readthrough frequency (%) |
Growth rate (% of wt.) | eRF1 expression level (% of wt.) | Ref. | ||
|---|---|---|---|---|---|---|---|---|
|
UAAC |
UAGC |
UGAC |
||||||
| wt [psi−] | – | 3.7 | 0.3 | 0.7 | 100 | 100 | This study | |
| wt [PSI+]s | – | 12.7 | 2.0 | 5.8 | 101 | nd | This study | |
| wt [PSI+]m | – | 9.8 | 1.1 | 3.4 | 99 | nd | This study | |
| wt [PSI+]w | – | 5.6 | 0.7 | 1.5 | 97 | nd | This study | |
| S30P | 0.4 | sl23ts | 5.0 | 0.6 | 1.3 | 99 | 101 | (20) |
| I32F | 1.0 | sup45-708 | 6.4 | 0.2 | 5.8 | 87 | 30 | (4) |
| L34S | −2.1 | sup45-36ts | Unstable | (34) | ||||
| P38L | −2.3 | sup45-718 | 7.1 | 0.9 | 3.5 | 80 | 96 | (4) |
| M48I | 2.5 | sup45-222 | 2.1 | 1.2 | 3.2 | 75 | 129 | (4) |
| L49A | −1.2 | 3.0 | 0.3 | 0.7 | 100 | nd | This study | |
| E52A | 0.0 | 3.4 | 0.3 | 0.7 | 100 | nd | This study | |
| G54D | 0.1 | Not viable | This study | |||||
| T55A | 0.6 | 5.4 | 0.4 | 0.6 | 97 | 86 | This study | |
| N58A | −0.3 | 22.4 | 1.9 | 3.8 | 71 | 140 | This study | |
| K60A | −0.4 | Not viable | This study | |||||
| S61A | 1.1 | 3.8 | 0.4 | 0.8 | 100 | nd | This study | |
| R62A | −0.6 | 5.1 | 0.4 | 1.1 | 92 | 87 | This study | |
| R65C | −2.2 | sup45-3 | Unstable | (35) | ||||
| V68A | 0.1 | sup45-731 | 8.9 | 0.3 | 4.6 | 87 | 85 | (4) |
| S74F | −2.8 | sup45-228 | 13.2 | 1.6 | 2.0 | 80 | 96 | (4) |
| V107D | −2.9 | 10.2 | 0.8 | 4.7 | 100 | 29 | This study | |
| D110G | 0.1 | sup45-242 | 12.2 | 0.9 | 2.8 | 98 | 119 | (4) |
| L123V | 1.8 | sup45-721 | 4.4 | 0.3 | 10.0 | 101 | 118 | (4) |
| H129R | 0.6 | sup45-707 | 4.3 | 0.3 | 5.4 | 98 | 96 | (4) |
| P174Q | −0.2 | 7.0 | 0.7 | 2.5 | 89 | 82 | This study | |
| K175A | −0.4 | Not viable | This study | |||||
| K176A | −0.4 | Not viable | This study | |||||
| G180A | 0.5 | Not viable | This study | |||||
| G181A | 0.5 | Not viable | This study | |||||
| Q182E | 1.7 | Unstable | (37) | |||||
| Q182N | 0.7 | Unstable | (37) | |||||
| I222S | −1.8 | sup45-2 | 9.1 | 1.4 | 3.9 | 88 | 85 | (36) |
| T295A | 0.6 | 3.7 | 0.4 | 0.7 | 100 | nd | This study | |
| T305A | 0.6 | 4.3 | 0.4 | 0.9 | 100 | nd | This study | |
| T357A | 0.6 | 3.9 | 0.4 | 0.8 | 100 | nd | This study | |
| T388A | 0.6 | 4.3 | 0.3 | 0.9 | 100 | nd | This study | |
| F401Y | 5.1 | 4.1 | 0.3 | 0.6 | 85 | nd | This study | |
| Y410F | 5.1 | 5.0 | 0.4 | 1.6 | 87 | 74 | This study | |
Statistically significant differences to wild-type are indicated in bold (P <0.05) or bold italic (P <0.01). All data for sup45 mutants were generated in a [psi−] background (strain YTH82/MT604).
aGiven as the log odds score for observing this amino acid substitution in natural protein alignments, based on the PAM250-normalized Gonnet matrix (42). Lower numbers indicate less frequently observed substitutions.
Nd, not determined.