4XCO

Signal-sequence induced conformational changes in the signal recognition particle

Summary for 4XCO

• Entry DOI: 10.2210/pdb4xco/pdb
• Related: 3ndb
• Descriptor: RNA, Signal recognition particle 19 kDa protein, Signal recognition particle 54 kDa protein,signal sequence, ... (6 entities in total)
• Functional Keywords: signal recognition particle, signal sequence, recombinant fusion protein, rna structure, rna binding protein
• Biological source: Methanocaldococcus jannaschii; More
• Cellular location: Cytoplasm : Q58440
• Total number of polymer chains: 6
• Total formula weight: 121854.77

Authors

Hainzl, T.,Sauer-Eriksson, A.E. (deposition date: 2014-12-18, release date: 2015-06-10, Last modification date: 2024-01-10)

Primary citation

Hainzl, T.,Sauer-Eriksson, A.E.
Signal-sequence induced conformational changes in the signal recognition particle.
Nat Commun, 6:7163-7163, 2015

PubMed Abstract: Co-translational protein targeting is an essential, evolutionarily conserved pathway for delivering nascent proteins to the proper cellular membrane. In this pathway, the signal recognition particle (SRP) first recognizes the N-terminal signal sequence of nascent proteins and subsequently interacts with the SRP receptor. For this, signal sequence binding in the SRP54 M domain must be effectively communicated to the SRP54 NG domain that interacts with the receptor. Here we present the 2.9 Å crystal structure of unbound- and signal sequence bound SRP forms, both present in the asymmetric unit. The structures provide evidence for a coupled binding and folding mechanism in which signal sequence binding induces the concerted folding of the GM linker helix, the finger loop, and the C-terminal alpha helix αM6. This mechanism allows for a high degree of structural adaptability of the binding site and suggests how signal sequence binding in the M domain is coupled to repositioning of the NG domain.

PubMed: 26051119
DOI: 10.1038/ncomms8163

Experimental method

X-RAY DIFFRACTION (2.9 Å)