PT  - JOURNAL ARTICLE
AU  - Ataide, Sandro F.
AU  - Schmitz, Nikolaus
AU  - Shen, Kuang
AU  - Ke, Ailong
AU  - Shan, Shu-ou
AU  - Doudna, Jennifer A.
AU  - Ban, Nenad
TI  - The Crystal Structure of the Signal Recognition Particle in Complex with Its Receptor
AID  - 10.1126/science.1196473
DP  - 2011 Feb 18
TA  - Science
PG  - 881--886
VI  - 331
IP  - 6019
4099  - http://science.sciencemag.org/content/331/6019/881.short
4100  - http://science.sciencemag.org/content/331/6019/881.full
SO  - Science2011 Feb 18; 331
AB  - Cotranslational targeting of membrane and secretory proteins is mediated by the universally conserved signal recognition particle (SRP). Together with its receptor (SR), SRP mediates the guanine triphosphate (GTP)–dependent delivery of translating ribosomes bearing signal sequences to translocons on the target membrane. Here, we present the crystal structure of the SRP:SR complex at 3.9 angstrom resolution and biochemical data revealing that the activated SRP:SR guanine triphosphatase (GTPase) complex binds the distal end of the SRP hairpin RNA where GTP hydrolysis is stimulated. Combined with previous findings, these results suggest that the SRP:SR GTPase complex initially assembles at the tetraloop end of the SRP RNA and then relocalizes to the opposite end of the RNA. This rearrangement provides a mechanism for coupling GTP hydrolysis to the handover of cargo to the translocon.