Structural highlights
3lqx is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Method: | X-ray diffraction, Resolution 1.93Å |
| Ligands: | , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The signal recognition particle (SRP) targets proteins to the endoplasmic reticulum in eukaryotes or to the inner membrane in prokaryotes by binding to hydrophobic signal sequences. Signal peptide recognition occurs within the highly conserved RNA-protein core of the SRP, underscoring the importance of this complex in SRP function. Structural analysis of the RNA and protein components of the prokaryotic SRP in the free and bound states revealed that the RNA undergoes a significant conformational change upon protein binding involving the uptake of several monovalent and divalent cations. To investigate the role of these metal ions in formation of the functional SRP complex, we used binding affinity assays and X-ray crystallography to analyze the specificity and energetic contributions of mono- and divalent metal ions bound in the RNA. Our results demonstrate that several metal ion binding sites important for RNA conformation can accommodate chemically distinct ions, often without affecting the structure of the complex. Thus, while these metal ions are highly ordered and essential for the formation and stability of the SRP complex, they behave like nonspecific metal ions.
Structural and energetic analysis of metal ions essential to SRP signal recognition domain assembly.,Batey RT, Doudna JA Biochemistry. 2002 Oct 1;41(39):11703-10. PMID:12269812[8]
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:http://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:http://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
- ↑ Batey RT, Doudna JA. Structural and energetic analysis of metal ions essential to SRP signal recognition domain assembly. Biochemistry. 2002 Oct 1;41(39):11703-10. PMID:12269812
