Movie
Controller
Structure viewers
About EMN Papers
+Search query
-Structure paper
| Title | Cryo-EM structure of a 40 kDa SAM-IV riboswitch RNA at 3.7 Å resolution. |
|---|---|
| Journal, issue, pages | Nat Commun, Vol. 10, Issue 1, Page 5511, Year 2019 |
| Publish date | Dec 3, 2019 |
 Authors | Kaiming Zhang / Shanshan Li / Kalli Kappel / Grigore Pintilie / Zhaoming Su / Tung-Chung Mou / Michael F Schmid / Rhiju Das / Wah Chiu /  |
| PubMed Abstract | Specimens below 50 kDa have generally been considered too small to be analyzed by single-particle cryo-electron microscopy (cryo-EM). The high flexibility of pure RNAs makes it difficult to obtain ...Specimens below 50 kDa have generally been considered too small to be analyzed by single-particle cryo-electron microscopy (cryo-EM). The high flexibility of pure RNAs makes it difficult to obtain high-resolution structures by cryo-EM. In bacteria, riboswitches regulate sulfur metabolism through binding to the S-adenosylmethionine (SAM) ligand and offer compelling targets for new antibiotics. SAM-I, SAM-I/IV, and SAM-IV are the three most commonly found SAM riboswitches, but the structure of SAM-IV is still unknown. Here, we report the structures of apo and SAM-bound SAM-IV riboswitches (119-nt, ~40 kDa) to 3.7 Å and 4.1 Å resolution, respectively, using cryo-EM. The structures illustrate homologies in the ligand-binding core but distinct peripheral tertiary contacts in SAM-IV compared to SAM-I and SAM-I/IV. Our results demonstrate the feasibility of resolving small RNAs with enough detail to enable detection of their ligand-binding pockets and suggest that cryo-EM could play a role in structure-assisted drug design for RNA. |
 External links | Nat Commun / PubMed:31796736 / PubMed Central |
| Methods | EM (single particle) |
| Resolution | 3.7 - 4.1 Å |
| Structure data | EMDB-20755, PDB-6ues: EMDB-20756, PDB-6uet: |
| Chemicals |  ChemComp-SAM: |
| Source |
|
 Keywords | RNA / SAM-IV riboswitch / Cryo-EM / Small RNA |
Helicobacter pylori (bacteria)
