Download MendeleySignal-sequence induced conformational changes in the signal recognition particle.
Hainzl, T., Sauer-Eriksson, A.E.(2015) Nat Commun 6: 7163-7163
- PubMed: 26051119
- DOI: https://doi.org/10.1038/ncomms8163
- Primary Citation of Related Structures:
4XCO - 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.
Organizational Affiliation:
Department of Chemistry, Umeå University, Umeå SE-901 87, Sweden.
