Table 1. Summary of the symbols used in the text.
E. coli data are taken from [5, 25, 26]. S. cerevisiae data are taken from [4, 26, 27]. In the text we also use symbols for the number of free, active, inactive and transcript-bound ribosomes, which are Rf, Ra, Ri and Rb, respectively.
| Definition and symbol | Typical values E. coli | Typical values S. cerevisiae |
|---|---|---|
| amino acid mass (maa) | 1.8 × 10−10pg | 1.8 × 10−10pg |
| total protein mass (M) | 0.1–1 pg | 1–10 pg |
| mass fraction of ribosomal proteins (ϕR) | 0.05–0.2 | 0.08–0.3 |
| total ribosomal protein mass (MR = ϕRM) | 0.005–0.5 pg | 0.08–3 pg |
| growth rate (λ) | 0–2 h−1 | 0–0.5 h−1 |
| typical number of aa in a protein (Lp) | 300 | 370 |
| total number of aa in a ribosome (LR) | ∼7300 | ∼12500 |
| typical protein mass (mp = maaLp) | 5 × 10−8 pg | 7 × 10−8 pg |
| protein mass of a ribosome (mR = maaLR) | 1 × 10−6 pg | 2 × 10−6 pg |
| total number of ribosomes (R = Ri + Rf + Rb) | 104 − 105 | 2–4 × 105 |
| total number of ribosomes (R = Ri + Ra) | 104 − 105 | 2–4 × 105 |
| codon elongation rate (k) | 8–20 aa/s | 10.5 aa/s |
| Jtl = maakϕR mass translational flux | 3–30 × 10−7 pg h−1 | 5.5–20 × 10−7 pg h−1 |
| γ = k/LR inverse time to translate a ribosome | 4–10 h−1 | 3 h−1 |