| Structural highlights
Function
[SRP54_ECOLI] Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Binds to the hydrophobic signal sequence of the ribosome-nascent chain (RNC) as it emerges from the ribosomes. The SRP-RNC complex is then targeted to the cytoplasmic membrane where it interacts with the SRP receptor FtsY. Interaction with FtsY leads to the transfer of the RNC complex to the Sec translocase for insertion into the membrane, the hydrolysis of GTP by both Ffh and FtsY, and the dissociation of the SRP-FtsY complex into the individual components.[1] [2] [3] [4] [5] [6] [7] [FTSY_ECOLI] Involved in targeting and insertion of nascent membrane proteins into the cytoplasmic membrane. Acts as a receptor for the complex formed by the signal recognition particle (SRP) and the ribosome-nascent chain (RNC). Interaction with SRP-RNC leads to the transfer of the RNC complex to the Sec translocase for insertion into the membrane, the hydrolysis of GTP by both Ffh and FtsY, and the dissociation of the SRP-FtsY complex into the individual components.[8] [9] [10] [11] [12] [13]
Publication Abstract from PubMed
The universally conserved signal recognition particle (SRP) system mediates the targeting of membrane proteins to the translocon in a multistep process controlled by GTP hydrolysis. Here we present the 2.6 A crystal structure of the GTPase domains of the E. coli SRP protein (Ffh) and its receptor (FtsY) in complex with the tetraloop and the distal region of SRP-RNA, trapped in the activated state in presence of GDP:AlF4. The structure reveals the atomic details of FtsY recruitment and, together with biochemical experiments, pinpoints G83 as the key RNA residue that stimulates GTP hydrolysis. Insertion of G83 into the FtsY active site orients a single glutamate residue provided by Ffh (E277), triggering GTP hydrolysis and complex disassembly at the end of the targeting cycle. The complete conservation of the key residues of the SRP-RNA and the SRP protein implies that the suggested chemical mechanism of GTPase activation is applicable across all kingdoms.
The Structural Basis of FtsY Recruitment and GTPase Activation by SRP RNA.,Voigts-Hoffmann F, Schmitz N, Shen K, Shan SO, Ataide SF, Ban N Mol Cell. 2013 Nov 6. pii: S1097-2765(13)00746-6. doi:, 10.1016/j.molcel.2013.10.005. PMID:24211265[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ribes V, Romisch K, Giner A, Dobberstein B, Tollervey D. E. coli 4.5S RNA is part of a ribonucleoprotein particle that has properties related to signal recognition particle. Cell. 1990 Nov 2;63(3):591-600. PMID:2171778
- ↑ Luirink J, High S, Wood H, Giner A, Tollervey D, Dobberstein B. Signal-sequence recognition by an Escherichia coli ribonucleoprotein complex. Nature. 1992 Oct 22;359(6397):741-3. PMID:1279430 doi:https://dx.doi.org/10.1038/359741a0
- ↑ Phillips GJ, Silhavy TJ. The E. coli ffh gene is necessary for viability and efficient protein export. Nature. 1992 Oct 22;359(6397):744-6. PMID:1331806 doi:https://dx.doi.org/10.1038/359744a0
- ↑ Powers T, Walter P. Co-translational protein targeting catalyzed by the Escherichia coli signal recognition particle and its receptor. EMBO J. 1997 Aug 15;16(16):4880-6. PMID:9305630 doi:10.1093/emboj/16.16.4880
- ↑ Peluso P, Shan SO, Nock S, Herschlag D, Walter P. Role of SRP RNA in the GTPase cycles of Ffh and FtsY. Biochemistry. 2001 Dec 18;40(50):15224-33. PMID:11735405
- ↑ Tian H, Beckwith J. Genetic screen yields mutations in genes encoding all known components of the Escherichia coli signal recognition particle pathway. J Bacteriol. 2002 Jan;184(1):111-8. PMID:11741850
- ↑ Froderberg L, Houben EN, Baars L, Luirink J, de Gier JW. Targeting and translocation of two lipoproteins in Escherichia coli via the SRP/Sec/YidC pathway. J Biol Chem. 2004 Jul 23;279(30):31026-32. Epub 2004 May 12. PMID:15140892 doi:10.1074/jbc.M403229200
- ↑ Luirink J, ten Hagen-Jongman CM, van der Weijden CC, Oudega B, High S, Dobberstein B, Kusters R. An alternative protein targeting pathway in Escherichia coli: studies on the role of FtsY. EMBO J. 1994 May 15;13(10):2289-96. PMID:8194520
- ↑ Powers T, Walter P. Co-translational protein targeting catalyzed by the Escherichia coli signal recognition particle and its receptor. EMBO J. 1997 Aug 15;16(16):4880-6. PMID:9305630 doi:10.1093/emboj/16.16.4880
- ↑ Peluso P, Shan SO, Nock S, Herschlag D, Walter P. Role of SRP RNA in the GTPase cycles of Ffh and FtsY. Biochemistry. 2001 Dec 18;40(50):15224-33. PMID:11735405
- ↑ Tian H, Beckwith J. Genetic screen yields mutations in genes encoding all known components of the Escherichia coli signal recognition particle pathway. J Bacteriol. 2002 Jan;184(1):111-8. PMID:11741850
- ↑ Buskiewicz I, Deuerling E, Gu SQ, Jockel J, Rodnina MV, Bukau B, Wintermeyer W. Trigger factor binds to ribosome-signal-recognition particle (SRP) complexes and is excluded by binding of the SRP receptor. Proc Natl Acad Sci U S A. 2004 May 25;101(21):7902-6. Epub 2004 May 17. PMID:15148364 doi:https://dx.doi.org/10.1073/pnas.0402231101
- ↑ Shan SO, Chandrasekar S, Walter P. Conformational changes in the GTPase modules of the signal reception particle and its receptor drive initiation of protein translocation. J Cell Biol. 2007 Aug 13;178(4):611-20. Epub 2007 Aug 6. PMID:17682051 doi:https://dx.doi.org/10.1083/jcb.200702018
- ↑ Voigts-Hoffmann F, Schmitz N, Shen K, Shan SO, Ataide SF, Ban N. The Structural Basis of FtsY Recruitment and GTPase Activation by SRP RNA. Mol Cell. 2013 Nov 6. pii: S1097-2765(13)00746-6. doi:, 10.1016/j.molcel.2013.10.005. PMID:24211265 doi:https://dx.doi.org/10.1016/j.molcel.2013.10.005
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