Component of the signal recognition particle (SRP) complex, a ribonucleoprotein complex that mediates the cotranslational targeting of secretory and membrane proteins to the endoplasmic reticulum (ER) . The SRP complex interacts with the signal sequence in nascent secretory and membrane proteins and directs them to the membrane of the ER . The SRP complex targets the ribosome-nascent chain complex to the SRP receptor (SR), which is anchored in the ER, where SR compaction and GTPase rearrangement drive cotranslational protein translocation into the ER . Binds the signal recognition particle RNA (7SL RNA) in presence of SRP68 (, ). Can bind 7SL RNA with low affinity (, ). The SRP complex possibly participates in the elongation arrest function (By similarity).
Subcellular locations: Cytoplasm, Endoplasmic reticulum