Table 1.
Modifications in the three functional regions examined
| Position | snoRNA | Helix | Conservation of sites | Association or function |
|---|---|---|---|---|
| A-site finger | ||||
| Ψ960 | snR8 | helix 37 | Ψ1664 (human) | |
| Ψ986 | snR8 | helix 38 | ||
| Ψ1004 | snR5 | helix 38 | Ψ1731 (human), Ψ1013 (A. thaliana) | |
| Ψ1042 | snR33 | helix 38 | Ψ1769 (human) | |
| Ψ1052 | snR81a | helix 38 | Ψ1779 (human) | |
| Ψ1124 | snR5 | helix 39 | Ψ1849 (human) | |
| Decoding center | ||||
| Um578 | snR77 | helix 18 | Um627 (human) Um580 (A. thaliana) | A-region |
| Ψ999 | snR31 | helix 24 | Ψ1056 (human) Ψ1000 (A. thaliana) | 3 nt next IF3 Association with 50S E-region |
| Cm1007 | snR79 | helix 24 | Next E-site tRNA | |
| Ψ1187 | snR36 | helix 31 | Ψ1244 (human) | Aa region |
| M1acp3Ψ1191 | snR35 | helix 31 | Gm966 (E. coli) Ψ1248 (human) | P-site tRNA Protein synthesis |
| Gm1271 | snR40b | helix 34 | Gm1328 (human) Gm 1272 (A. thaliana) | Downstream cross-links to mRNA A-region |
| Gm1428 | snR56 | helix 34 | Gm1490 (human) Gm 1431 (A. thaliana) | 2 nt next cross-links site to mRNA Aa region |
| Cm1639 | snR70 | helix 44 | Cm1402 (E. coli) Cm1703 (human) Cm 1641 (A. thaliana) | Downstream cross-links to mRNA P-region |
| Helix 69 | ||||
| Am2256 | snR63 | helix 69 | Am3749 (human) | A-site tRNA D-stem Contact H44 (DC) |
| Ψ2258 | snR191 | helix 69 | m3Ψ1915 (E. coli) Ψ3741 (human) Ψ2248 (A. thaliana) | A-site tRNA D-stem Contact H44 (DC) Translational fidelity Contact RF3 Translation termination |
| Ψ2260 | snR191 | helix 69 | Ψ1917 (E. coli) Ψ3743 (human) Ψ2250 (A. thaliana) | Translation termination |
| Ψ2264 | snR3c | helix 69 | Ψ3747 (human) | |
| Ψ2266 | snR84 | helix 69 | Ψ3749 (human) | P-site tRNA D-stem |
asnR81 also guides position Ψ42 in U2 snRNA.
bsnR40 also guides position Um898 in 25 S rRNA.
csnR3 also guides Ψ2129 in helix 64 and Ψ2133 in helix 65.