| Subunit |
Molecular weight |
Source |
Function |
| α (I) |
70,000 |
Protein S1 of 30S ribosomal subunit |
Qβ RNA binding,Inhibits protein synthesis on other phages |
| β (II) |
65,000 |
Virus specified |
Chain elongation |
| γ (III) |
45,000 |
Elongation factor (EF - Tu) |
Initiation |
| δ (IV) |
35,000 |
Elongation factor (EF - Ts) |
Initiation |
| HFI |
72,000 (hexamer) |
Ribosome-associate protein |
Minus strand synthesis |
