Signal recognition particle subunit SRP54 (SRP54)

Signal recognition particle subunit SRP54 is an essential, conserved GTPase that forms the core of the signal recognition particle (SRP). It recognizes the hydrophobic signal sequences of nascent proteins as they emerge from the ribosome. SRP54 comprises an N-terminal domain, a central catalytic GTPase domain, and a C-terminal methionine-rich M domain that binds the signal sequence and SRP RNA. Through GTP-dependent interaction with the SRP receptor, SRP54 facilitates the transfer of the ribosome-nascent chain complex to the translocon at cellular membranes, enabling correct sorting and translocation of secretory and membrane proteins. SRP54 is conserved across all domains of life, and its malfunction disrupts protein targeting, which is vital for cell viability.

Other names

Signal recognition particle 54 kDa proteinSignal recognition particle subunit SRP54signal recognition particle 54kDsignal recognition particle 54kDaSRP54Ffh (bacterial homolog)

Not applicable for drugs; mechanistically, SRP54 binds GTP and hydrolyzes it to mediate recognition and transfer of ribosome-nascent chain complexes to the protein translocon