2yhs
Structure of the E. coli SRP receptor FtsY
Structural highlights
FunctionFTSY_ECOLI Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Acts as a receptor for the complex formed by the signal recognition particle (SRP) and the ribosome-nascent chain (RNC). Interaction with SRP-RNC leads to the transfer of the RNC complex to the Sec translocase for insertion into the membrane, the hydrolysis of GTP by both Ffh and FtsY, and the dissociation of the SRP-FtsY complex into the individual components.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedCo-translational protein targeting to the membrane is mediated by the signal recognition particle (SRP) and its receptor (FtsY). Their homologous GTPase domains interact at the membrane and form a heterodimer in which both GTPases are activated. The prerequisite for protein targeting is the interaction of FtsY with phospholipids. However, the mechanism of FtsY regulation by phospholipids remained unclear. Here we show that the N-terminus of FtsY (A domain) is natively unfolded in solution and define the complete membrane targeting sequence (MTS). We show that the MTS is highly dynamic in solution, independent of nucleotides and directly responds to the density of anionic phospholipids by a random coil-helix transition. This conformational switch is essential for tethering FtsY to membranes and activates the GTPase for its subsequent interaction with SRP. Our results underline the dynamics of lipid/protein interactions and their importance in the regulation of protein targeting and translocation across biological membranes. Lipids trigger a conformational switch regulating signal recognition particle (SRP)-mediated protein targeting.,Stjepanovic G, Kapp K, Bange G, Graf C, Parlitz R, Wild K, Mayer MP, Sinning I J Biol Chem. 2011 May 3. PMID:21543314[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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