Signal recognition particle protein

Signal recognition particle (SRP) is a ribonucleoprotein which targets specific proteins to the endoplasmic reticulum (ER) in eukaryotes and the plasma membrane in prokaryotes. In eukaryotes SRP binds to the signal sequence of a newly synthesized polypeptide as it emerges from the ribosome. The binding allows for the coupling of the translation process to the translocation process. The SRP targets the nascent protein to the ER by docking into the SRP receptor. The eukaryotic SRP which has GTPase activity, is composed of SRP9, SRP14, SRP19, SRP54, SRP68, SRP72 and 7S RNA. The prokaryotic SRP is composed of FFH (SRP54-like) and 4.5S RNA. 3D structures of signal recognition particle Signal recognition particle 3D structures Updated on 05-May-2025 {{#tree:id=OrganizedByTopic|openlevels=0| Signal recognition particle 6y2z – hSRP54 NG domain 1-296 - human 6y30, 6y31 – hSRP54 NG domain (mutant) 1qb2 – hSRP54 M domain 326-434 4p3f – hSRP68 (mutant) 5m72, 5wrv – hSRP68 + SRP72 5wrw – hSRP72 1914 – mSRP9/SRP14 – mouse 1wgw – mSRP54 N terminal – NMR 2hug – AtSRP43 chromodomain 2 + SRP54 M domain – Arabidopsis thaliana – NMR 1x32 - AtSRP43 chromodomain 1 – NMR 5e4x - AtSRP43 chromodomain 3 3deo - AtSRP43 residues 85-267 3ui2 - AtSRP43 residues 84-327 + AtSRP54 RRKR motif 2w9j – SRP14 residues 1-91 – fission yeast 1ls1, 2j45, 2j46, 1ffh, 1ng1, 3ng1 - TaSRP54-like NG domain – Thermus aquaticus 2ng1 - TaSRP54-like NG domain (mutant) 2ffh - TaSRP54-like residues 1-425 (mutant) 1kvn, 1kvv – AfSRP19 (mutant) – Archaeoglobus fulgidus – NMR 2jqe – AfSRP54 M domain 313-433 – NMR 3dlu, 3dlv, 3dm5 – SRP19 – Pyrococcus furiosus 1j8m – AaSPR GTPase domain – Acicianus ambivalens 1j8y – AaSPR GTPase domain (mutant) 1qzx – SsSRP54 – Sulfolobus solfataricus Signal recognition particle complexes with RNA 1e8o, 1e8s, 5aox - hSRP9 + hSRP14 + 7S RNA 5m73 - hSRP19 + hSRP68 + SRP72 + 7S RNA 1ry1 - hSRP9 + hSRP14 + hSRP19 + hSRP54 + 7S RNA 4uyj, 4uyk - hSRP9 + hSRP14 + RNA 1jid – hSRP19 + RNA 3ktv - hSRP19 + RNA S domain 1mfq – hSRP19 + hSRP54 M domain + 7S RNA S domain 2j37 - hSRP19 + SRP54 + ribosomal proteins L23, L31, L35 + RNA – Cryo EM 2go5 – dSRP19 + SRP54 + hSRP receptor α subunit + mSRP receptor b subunit + ribosomal proteins L23, L31, L35 + RNA – dog 7obq, 7obr – dSRP19 + SRP54 + SRP68 + SRP72 + SRP receptor ubunit a + RNA – Cryo EM 4ue5 – dSRP9 + SRP14 + SRP54 + SRP68 + RNA – Cryo EM 3ktw - SsSRP19 + RNA S domain 1qzw – SsSRP + 7S RNA 1lng – MjSRP19 + RNA – Methanocaldococcus jannaschii 1l9a - MjSRP19 (mutant) + RNA 2v3c, 3ndb, 4xco - MjSRP19 + MjSRP54 + 7S RNA 2iy3 – TaSRP54-like + RNA - EM 1dul, 1hq1, 2pxp – EcSRP54-like C terminal + RNA – Escherichia coli 3lqx - EcSRP54-like + RNA + Co-hexamine 2xkv - EcSRP54-like NG+M domains + 4.5SRNA – Cryo EM 2xxa - EcSRP54-like residues 1-433 (mutant) + cell division protein FtsY residues 196-497+ 4.5SRNA 7o9f, 7o9g, 7o9i - EcSRP54-like residues 2-299 + ppGpp 3zn8 - EcSRP54 NG domain + cell division protein FtsY residues 201-495+ 4.5SRNA + dipeptidyl aminopeptidase B 2pxb, 2pxd, 2pxe, 2pxf, 2pxk, 2pxl, 2pxq, 2pxq, 2pxt, 2pxu, 2pxv - EcSRP54-like C terminal + 4.5SRNA domain IV (mutant) 2j28 – EcSRP54-like + 70S ribosome – Cryo EM 4ue4 – BsSRP M domain + FtsQ signal sequence + RNA - Bacillus subtilis 7o5b – BsSRP in 70S ribosome + ppGpp – Cryo EM Other signal recognition particle complexes 5l3q, 6y32 – hSRP54 + SRP receptor subunit α 3dep - AtSRP43 residues 85-267 + polypeptide 5e4w - AtSRP43 chromodomain 2-3 + thioredoxin + ALB3 tail 5l3r - AtSRP54 + cell division protein FTSY 1jpj, 1jpn, 2c04 – TaSRP54-like NG domain + GMPPNP 1o87, 2c03 - TaSRP54-like NG domain + GDP 1okk, 1rj9, 2cnw - TaSRP54-like NG domain + cell division protein FtsY 2j7p - TaSRP54-like NG domain + cell division protein FtsY + GMPPNP 5l3s - SsSRP54 + cell division protein FtsY 3kl4 – SsSRP54 residues 2-432 + polypeptide 5l3v - SsSRP54 + GDP 7epk - SRP54 + GDP – Aeropyrum pernix 4c7o – EcSRP + FtsY + SRP RNA }}

spinqualitylabelsall models Human SRP9 (grey and pink) +SRP14 (green and yellow) complex with 7S RNA, GDP and sulfate 1e8o Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image