RT Journal Article
SR Electronic
T1 The Crystal Structure of the Signal Recognition Particle in Complex with Its Receptor
JF Science
JO Science
FD American Association for the Advancement of Science
SP 881
OP 886
DO 10.1126/science.1196473
VO 331
IS 6019
A1 Ataide, Sandro F.
A1 Schmitz, Nikolaus
A1 Shen, Kuang
A1 Ke, Ailong
A1 Shan, Shu-ou
A1 Doudna, Jennifer A.
A1 Ban, Nenad
YR 2011
UL http://science.sciencemag.org/content/331/6019/881.abstract
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.