Signal recognition particle receptor

The SRP - receptor (SR, DP), which is also referred to as a docking protein, is a protein located in the endoplasmic reticulum in eukaryotes and prokaryotes in the plasma membrane. It plays an important role in protein biosynthesis, transport, membrane and export proteins. The Hauptligand SR is the signal recognition particle (SRP ), a protein complex that binds to the so-called signal sequence of the resulting peptide, while the protein synthesis, so that the translation is stopped until the SRP, a G- protein which bind to the SRP receptor. Through this interaction, contact between the ribosome and translocase is mediated. By hydrolysis of GTP in the SRP and SRP- receptor results in a dissociation of the compound and the protein can be continued cotranslationally in the lumen of the endoplasmic reticulum or the plasma membrane.

The SRP - receptor is a dimer of two G- proteins, peripheral α - subunit protein and an integral β subunit. In prokaryotes there is a homologue of the α - subunit.

Source

H. Kleinig, U. Maier: Cell Biology. Gustav Fischer Verlag, 1999, 4th edition, pp. 249-252, ISBN 3-437-26010-3

Transportprotein Guanosine triphosphate Protein subunit
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