4xco
From Proteopedia
Signal-sequence induced conformational changes in the signal recognition particle
Structural highlights
FunctionSRP19_METJA Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Binds directly to 7S RNA and mediates binding of the 54 kDa subunit of the SRP (By similarity). Publication Abstract from PubMedCo-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 A 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 alphaM6. 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. Signal-sequence induced conformational changes in the signal recognition particle.,Hainzl T, Sauer-Eriksson AE Nat Commun. 2015 Jun 8;6:7163. doi: 10.1038/ncomms8163. PMID:26051119[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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