Q75K18 · SRP54_DICDI

Function

function

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). As part of the SRP complex, associates with the SRP receptor (SR) component srpra to target secretory proteins to the endoplasmic reticulum membrane. Binds to the signal sequence of presecretory proteins when they emerge from the ribosomes. Displays basal GTPase activity, and stimulates reciprocal GTPase activation of the SR subunit SRPRA. Forms a guanosine 5'-triphosphate (GTP)-dependent complex with the SR subunit srpra. SR compaction and GTPase mediated rearrangement of SR drive SRP-mediated cotranslational protein translocation into the ER (By similarity).
Requires the presence of srp9/srp14 and/or srp19 to stably interact with RNA (By similarity).

Catalytic activity

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site108-115GTP (UniProtKB | ChEBI)
Binding site190-194GTP (UniProtKB | ChEBI)
Binding site248-251GTP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcytosol
Cellular Componentendoplasmic reticulum
Cellular Componentphagocytic vesicle
Cellular Componentsignal recognition particle, endoplasmic reticulum targeting
Molecular Function7S RNA binding
Molecular FunctionATP hydrolysis activity
Molecular Functionendoplasmic reticulum signal peptide binding
Molecular FunctionGTP binding
Molecular FunctionGTPase activity
Biological ProcessSRP-dependent cotranslational protein targeting to membrane, translocation

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Signal recognition particle subunit SRP54
  • EC number
  • Alternative names
    • Signal recognition particle 54 kDa protein

Gene names

    • Name
      srp54
    • ORF names
      DDB_G0275455

Organism names

Accessions

  • Primary accession
    Q75K18
  • Secondary accessions
    • Q552P1

Proteomes

Organism-specific databases

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003276781-542Signal recognition particle subunit SRP54

Proteomic databases

Interaction

Subunit

Component of a signal recognition particle (SRP) complex that consists of a 7SL RNA molecule of 300 nucleotides and six protein subunits: srp72, srp68, srp54, srp19, srp14 and srp9.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region1-295G-domain
Region296-542M-domain

Domain

The NG domain, also named G domain, is a special guanosine triphosphatase (GTPase) domain, which binds GTP and forms a guanosine 5'-triphosphate (GTP)-dependent complex with a homologous NG domain in the SRP receptor subunit srpra. The two NG domains undergo cooperative rearrangements upon their assembly, which culminate in the reciprocal activation of the GTPase activity of one another. SRP receptor compaction upon binding with cargo-loaded SRP and GTPase rearrangement drive SRP-mediated cotranslational protein translocation into the ER.
The M domain binds the 7SL RNA in presence of srp19 and binds the signal sequence of presecretory proteins.

Sequence similarities

Belongs to the GTP-binding SRP family. SRP54 subfamily.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    542
  • Mass (Da)
    57,610
  • Last updated
    2004-07-05 v1
  • Checksum
    F5AE74963AD00D20
MVLADLGNQLSSALRSLNETTIVNEDTINQLLKEVGNALSKSDVSMSLIIQMRKNIKDKIKLDQMAAGLNKRKIIKQVVFDELIRLLDPGVPLWKPTKGKSNIVMFVGLQGAGKTTSVTKLAYFYKKKGFSTAIVCADTFRAGAFDQVRHNAAKAKIHYYGSETEKDPVVVARTGVDIFKKDGTEIIIVDTSGRHKQDSELFEEMKQIETAVKPDNCIFVMDSSIGQAAYEQATAFRSSVKVGSIIITKMDGNSMGGGAISAVAATNTPIIFIGTGEHLTDLELFDPSTFVSKLLGYGDMKGMLEKIKEVIPEDSTSLKEIAQGKFTLRSMQQQFQQIMQLGPIDKLVQMIPGMNQLPQLQGNEGGLKLKAYINILDSLSEKELDGKKPITQKRIITIAQGSGRHPNEVVELLEQHKTFEKLIGKGGPGGGLGSLMAGKGGPKNMEQAMKQMNANGGMQGLMNSLKGMGGMGDLAKMFGGGGGGGGGMPSMGDLAKMMGGMGGGGRGGGGMPNMGDLAKMMGGMGGGAGKGGQNGFPNLDLD

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AAFI02000013
EMBL· GenBank· DDBJ
EAL69478.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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