Signal recognition particle (SRP) receptor, also called the docking protein, is a dimer composed of 2 different subunits that are associated exclusively with the rough ER in mammaliancells. Its main function is to identify the SRP units. SRP (signal recognition particle) is a molecule that helps the ribosome-mRNA-polypeptide complexes to settle down on the membrane of the endoplasmic reticulum.
Signal recognition particle (SRP) receptor alpha subunit, N-terminal
Structure of the beta subunit of the eukaryotic signal recognition particle receptor.[1]
The eukaryotic SRP receptor (termed SR) is a heterodimer of SR-alpha (70 kDa; SRPRA) and SR-beta (25 kDa; SRPRB), both of which contain a GTP-binding domain,[2] while the prokaryotic SRP receptor comprises only the monomeric loosely membrane-associated SR-alpha homologue FtsY (P10121).
SR-alpha regulates the targeting of SRP-ribosome-nascent polypeptide complexes to the translocon.[3] SR-alpha binds to the SRP54 subunit of the SRP complex. The SR-beta subunit is a transmembrane GTPase that anchors the SR-alpha subunit (a peripheral membrane GTPase) to the ER membrane.[4] SR-beta interacts with the N-terminal SRX-domain of SR-alpha, which is not present in the bacterial FtsY homologue. SR-beta also functions in recruiting the SRP-nascent polypeptide to the protein-conducting channel.
The SRX family represents eukaryotic homologues of the alpha subunit of the SR receptor. Members of this entry consist of a central six-stranded anti-parallel beta-sheet sandwiched by helix alpha1 on one side and helices alpha2-alpha4 on the other. They interact with the small GTPase SR-beta, forming a complex that matches a class of small G protein-effector complexes, including Rap-Raf, Ras-PI3K(gamma), Ras-RalGDS, and Arl2-PDE(delta).[2] On the C-terminal of SR-alpha and FtsY is the NG domain similar to SRP54.
NG domainedit
The receptor binds to SPR54/Ffh by the "NG domain", a combination of a 4-helical-bundle "N" domain (InterPro: IPR013822) and a GTPase "G" domain (InterPro: IPR000897), shared by both proteins. The bound structure is a quasi-symmetric heterodimer termed a targeting complex.[5]
Signal recognition particle (SRP)edit
The signal recognition particle (SRP) is a multimeric protein, which along with its conjugate receptor (SR), is involved in targeting secretory proteins to the rough endoplasmic reticulum (RER) membrane in eukaryotes, or to the plasma membrane in prokaryotes.[6][7] SRP recognises the signal sequence of the nascent polypeptide on the ribosome, retards its elongation, and docks the SRP-ribosome-polypeptide complex to the RER membrane via the SR receptor. SRP consists of six polypeptides (SRP9, SRP14, SRP19, SRP54, SRP68 and SRP72) and a single 300 nucleotide 7S RNA molecule. The RNA component catalyses the interaction of SRP with its SR receptor.[8] In higher eukaryotes, the SRP complex consists of the Alu domain and the S domain linked by the SRP RNA. The Alu domain consists of a heterodimer of SRP9 and SRP14 bound to the 5' and 3' terminal sequences of SRP RNA. This domain is necessary for retarding the elongation of the nascent polypeptide chain, which gives SRP time to dock the ribosome-polypeptide complex to the RER membrane.
Referencesedit
^Schwartz T, Blobel G (March 2003). "Structural basis for the function of the beta subunit of the eukaryotic signal recognition particle receptor". Cell. 112 (6): 793–803. doi:10.1016/S0092-8674(03)00161-2. PMID 12654246.
^ abBlobel G, Schwartz T (2003). "Structural basis for the function of the beta subunit of the eukaryotic signal recognition particle receptor". Cell. 112 (6): 793–803. doi:10.1016/S0092-8674(03)00161-2. PMID 12654246.
^Andrews DW, Legate KR, Falcone D (2000). "Nucleotide-dependent binding of the GTPase domain of the signal recognition particle receptor beta-subunit to the alpha-subunit". J. Biol. Chem. 275 (35): 27439–46. doi:10.1074/jbc.M003215200. PMID 10859309.
^Walter P, Miller JD, Tajima S, Lauffer L (1995). "The beta subunit of the signal recognition particle receptor is a transmembrane GTPase that anchors the alpha subunit, a peripheral membrane GTPase, to the endoplasmic reticulum membrane". J. Cell Biol. 128 (3): 273–282. doi:10.1083/jcb.128.3.273. PMC2120348. PMID 7844142.
^Wild, Klemens; Becker, Matthias M.M.; Kempf, Georg; Sinning, Irmgard (18 December 2019). "Structure, dynamics and interactions of large SRP variants". Biological Chemistry. 401 (1): 63–80. doi:10.1515/hsz-2019-0282.
^Stroud RM, Walter P, Rutenber E, Reyes CL (2007). Zhang S (ed.). "X-ray Structures of the Signal Recognition Particle Receptor Reveal Targeting Cycle Intermediates". PLOS ONE. 2 (7): e607. Bibcode:2007PLoSO...2..607R. doi:10.1371/journal.pone.0000607. PMC1904258. PMID 17622352.
^Dobberstein B, High S, Romisch K, Miller FW (2006). "Human autoantibodies against the 54 kDa protein of the signal recognition particle block function at multiple stages". Arthritis Research & Therapy. 8 (2): R39. doi:10.1186/ar1895. PMC1526608. PMID 16469117.
^Walter P, Bradshaw N (2007). "The Signal Recognition Particle (SRP) RNA Links Conformational Changes in the SRP to Protein Targeting". Mol. Biol. Cell. 18 (7): 2728–2734. doi:10.1091/mbc.E07-02-0117. PMC1924838. PMID 17507650.
This article incorporates text from the public domain Pfam and InterPro: IPR015284
December 15, 2023
signal, recognition, particle, receptor, signal, recognition, particle, receptor, also, called, docking, protein, dimer, composed, different, subunits, that, associated, exclusively, with, rough, mammalian, cells, main, function, identify, units, signal, recog. Signal recognition particle SRP receptor also called the docking protein is a dimer composed of 2 different subunits that are associated exclusively with the rough ER in mammalian cells Its main function is to identify the SRP units SRP signal recognition particle is a molecule that helps the ribosome mRNA polypeptide complexes to settle down on the membrane of the endoplasmic reticulum Signal recognition particle SRP receptor alpha subunit N terminalStructure of the beta subunit of the eukaryotic signal recognition particle receptor 1 IdentifiersSymbolSRXPfamPF09201InterProIPR015284SCOP21nrj SCOPe SUPFAMOPM superfamily136OPM protein1nrjMembranome38Available protein structures Pfam structures ECOD PDBRCSB PDB PDBe PDBjPDBsumstructure summaryThe eukaryotic SRP receptor termed SR is a heterodimer of SR alpha 70 kDa SRPRA and SR beta 25 kDa SRPRB both of which contain a GTP binding domain 2 while the prokaryotic SRP receptor comprises only the monomeric loosely membrane associated SR alpha homologue FtsY P10121 Contents 1 SRX domain 2 NG domain 3 Signal recognition particle SRP 4 ReferencesSRX domain editSR alpha regulates the targeting of SRP ribosome nascent polypeptide complexes to the translocon 3 SR alpha binds to the SRP54 subunit of the SRP complex The SR beta subunit is a transmembrane GTPase that anchors the SR alpha subunit a peripheral membrane GTPase to the ER membrane 4 SR beta interacts with the N terminal SRX domain of SR alpha which is not present in the bacterial FtsY homologue SR beta also functions in recruiting the SRP nascent polypeptide to the protein conducting channel The SRX family represents eukaryotic homologues of the alpha subunit of the SR receptor Members of this entry consist of a central six stranded anti parallel beta sheet sandwiched by helix alpha1 on one side and helices alpha2 alpha4 on the other They interact with the small GTPase SR beta forming a complex that matches a class of small G protein effector complexes including Rap Raf Ras PI3K gamma Ras RalGDS and Arl2 PDE delta 2 On the C terminal of SR alpha and FtsY is the NG domain similar to SRP54 NG domain editThe receptor binds to SPR54 Ffh by the NG domain a combination of a 4 helical bundle N domain InterPro IPR013822 and a GTPase G domain InterPro IPR000897 shared by both proteins The bound structure is a quasi symmetric heterodimer termed a targeting complex 5 Signal recognition particle SRP editThe signal recognition particle SRP is a multimeric protein which along with its conjugate receptor SR is involved in targeting secretory proteins to the rough endoplasmic reticulum RER membrane in eukaryotes or to the plasma membrane in prokaryotes 6 7 SRP recognises the signal sequence of the nascent polypeptide on the ribosome retards its elongation and docks the SRP ribosome polypeptide complex to the RER membrane via the SR receptor SRP consists of six polypeptides SRP9 SRP14 SRP19 SRP54 SRP68 and SRP72 and a single 300 nucleotide 7S RNA molecule The RNA component catalyses the interaction of SRP with its SR receptor 8 In higher eukaryotes the SRP complex consists of the Alu domain and the S domain linked by the SRP RNA The Alu domain consists of a heterodimer of SRP9 and SRP14 bound to the 5 and 3 terminal sequences of SRP RNA This domain is necessary for retarding the elongation of the nascent polypeptide chain which gives SRP time to dock the ribosome polypeptide complex to the RER membrane References edit Schwartz T Blobel G March 2003 Structural basis for the function of the beta subunit of the eukaryotic signal recognition particle receptor Cell 112 6 793 803 doi 10 1016 S0092 8674 03 00161 2 PMID 12654246 a b Blobel G Schwartz T 2003 Structural basis for the function of the beta subunit of the eukaryotic signal recognition particle receptor Cell 112 6 793 803 doi 10 1016 S0092 8674 03 00161 2 PMID 12654246 Andrews DW Legate KR Falcone D 2000 Nucleotide dependent binding of the GTPase domain of the signal recognition particle receptor beta subunit to the alpha subunit J Biol Chem 275 35 27439 46 doi 10 1074 jbc M003215200 PMID 10859309 Walter P Miller JD Tajima S Lauffer L 1995 The beta subunit of the signal recognition particle receptor is a transmembrane GTPase that anchors the alpha subunit a peripheral membrane GTPase to the endoplasmic reticulum membrane J Cell Biol 128 3 273 282 doi 10 1083 jcb 128 3 273 PMC 2120348 PMID 7844142 Wild Klemens Becker Matthias M M Kempf Georg Sinning Irmgard 18 December 2019 Structure dynamics and interactions of large SRP variants Biological Chemistry 401 1 63 80 doi 10 1515 hsz 2019 0282 Stroud RM Walter P Rutenber E Reyes CL 2007 Zhang S ed X ray Structures of the Signal Recognition Particle Receptor Reveal Targeting Cycle Intermediates PLOS ONE 2 7 e607 Bibcode 2007PLoSO 2 607R doi 10 1371 journal pone 0000607 PMC 1904258 PMID 17622352 nbsp Dobberstein B High S Romisch K Miller FW 2006 Human autoantibodies against the 54 kDa protein of the signal recognition particle block function at multiple stages Arthritis Research amp Therapy 8 2 R39 doi 10 1186 ar1895 PMC 1526608 PMID 16469117 Walter P Bradshaw N 2007 The Signal Recognition Particle SRP RNA Links Conformational Changes in the SRP to Protein Targeting Mol Biol Cell 18 7 2728 2734 doi 10 1091 mbc E07 02 0117 PMC 1924838 PMID 17507650 This article incorporates text from the public domain Pfam and InterPro IPR015284 Retrieved from https en wikipedia org w index php title Signal recognition particle receptor amp oldid 1188127353, wikipedia, wiki, book, books, library,
