Table 1.
Average times for dipeptide synthesis from fMet-tRNAfMet and different aminoacyl-tRNAs
| Aminoacyl-tRNA | Codon | τdip, ms | τGTP, ms | τacc,pep, ms |
|---|---|---|---|---|
| Phe-tRNAPhe | UUU | 19.6 (±2.1) | 7.8 (±0.6) | 11.9 (±2.1) |
| Phe-tRNAPhe | UUC | 18.5 (±1.7) | 7.7 (±0.6) | 10.8 (±1.8) |
| Phe-tRNABulk | UUC | 20.4 (±1.7) | 8.9 (±0.8) | 11.5 (±1.9) |
| Phe-tRNAPheB | UUC | 24.4 (±2.3) | 13.0 (±0.7) | 11.4 (±2.4) |
| N-methyl-Phe-tRNAPheB | UUC | 200,000 (±12,000) | 52.6 (±7.3) | 199,900 (±12,000) |
| N-butyl-Phe-tRNAPheB | UUC | Undetectable | 67.7 (±27) | Undetectable |
| Ala-tRNAPheB | UUC | 37.0 (±5.1) | 13.2 (±1.4) | 23.9 (±7.1) |
| Pro-tRNAPheB | UUC | 571.3 (±65) | 16.1 (±3.2) | 555 (±65) |
| Pro-tRNABulk | CCG | 62.5 (±7.6) | 12.5 (±1.4) | 50.0 (±7.7) |
| Pro-tRNABulk | CCA | 66.7 (±8.9) | 18.9 (±2.8) | 47.8 (±9.3) |
| Pro-tRNABulk | CCU | 71.4 (±9.7) | 23.8 (±3.5) | 47.6 (±10.3) |
| Pro-tRNABulk | CCC | 116.3 (±16.1) | 50.0 (±5.1) | 66.3 (±16.9) |
Data are expressed as average times for GTP hydrolysis (τGTP) and dipeptide synthesis (τdip) measured in the same reaction mixture. The average time for accommodation/peptidyl transfer is calculated as τacc,pep = τdip − τGTP. All experiments were conducted at 37 °C in high-accuracy polyamine containing LS3 buffer (see Materials and Methods); each experiment was performed at least twice.