Summary information and primary citation

6vvj; DSSR-derived features in text and JSON formats
Brown JD, Kharytonchyk S, Chaudry I, Iyer AS, Carter H, Becker G, Desai Y, Glang L, Choi SH, Singh K, Lopresti MW, Orellana M, Rodriguez T, Oboh U, Hijji J, Ghinger FG, Stewart K, Francis D, Edwards B, Chen P, Case DA, Telesnitsky A, Summers MF (2020): "Structural basis for transcriptional start site control of HIV-1 RNA fate." Science, 368, 413-417. doi: 10.1126/science.aaz7959.
Heterogeneous transcriptional start site usage by HIV-1 produces 5'-capped RNAs beginning with one, two, or three 5'-guanosines (Cap1G, Cap2G, or Cap3G, respectively) that are either selected for packaging as genomes (Cap1G) or retained in cells as translatable messenger RNAs (mRNAs) (Cap2G and Cap3G). To understand how 5'-guanosine number influences fate, we probed the structures of capped HIV-1 leader RNAs by deuterium-edited nuclear magnetic resonance. The Cap1G transcript adopts a dimeric multihairpin structure that sequesters the cap, inhibits interactions with eukaryotic translation initiation factor 4E, and resists decapping. The Cap2G and Cap3G transcripts adopt an alternate structure with an elongated central helix, exposed splice donor residues, and an accessible cap. Extensive remodeling, achieved at the energetic cost of a G-C base pair, explains how a single 5'-guanosine modifies the function of a ~9-kilobase HIV-1 transcript.

Cartoon-block schematics in six views (download the tarball)

PyMOL session file Download PDB file View in 3Dmol.js