1nrj: Difference between revisions

Revision as of 15:09, 21 February 2008

Signal Recognition Particle Receptor Beta-Subunit in Complex with the SRX Domain from the Alpha-Subunit

OverviewOverview

Protein translocation across and insertion into membranes is a process essential to all life forms. In higher eukaryotes, this process is initiated by targeting the translating ribosome to the endoplasmic reticulum via the signal recognition particle (SRP) and its membrane-associated heterodimeric receptor (SR). This targeting step is regulated by three G proteins, SRP54, SR alpha, and SR beta, which act in concert. Little is known about the regulatory role of SR beta. Here, we present the 1.7 A crystal structure of the SR beta-GTP subunit in complex with the interaction domain of SR alpha. Strikingly, the binding interface overlaps largely with the switch 1 region of SR beta. This finding, together with additional biochemical data, shows that the eukaryotic SR is a conditional and not an obligate heterodimer. The results suggest that the GTP/GDP switch cycle of SR beta functions as a regulatory switch for the receptor dimerization. We discuss the implications for the translocation pathway.

About this StructureAbout this Structure

1NRJ is a Protein complex structure of sequences from Saccharomyces cerevisiae with , and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

Structural basis for the function of the beta subunit of the eukaryotic signal recognition particle receptor., Schwartz T, Blobel G, Cell. 2003 Mar 21;112(6):793-803. PMID:12654246

Page seeded by OCA on Thu Feb 21 14:09:12 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

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-[[Image:1nrj.gif|left|200px]]<br /><applet load="1nrj" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1nrj.gif|left|200px]]<br /><applet load="1nrj" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1nrj, resolution 1.70&Aring;" />
 '''Signal Recognition Particle Receptor Beta-Subunit in Complex with the SRX Domain from the Alpha-Subunit'''<br />
 ==Overview==
-Protein translocation across and insertion into membranes is a process, essential to all life forms. In higher eukaryotes, this process is, initiated by targeting the translating ribosome to the endoplasmic, reticulum via the signal recognition particle (SRP) and its, membrane-associated heterodimeric receptor (SR). This targeting step is, regulated by three G proteins, SRP54, SR alpha, and SR beta, which act in, concert. Little is known about the regulatory role of SR beta. Here, we, present the 1.7 A crystal structure of the SR beta-GTP subunit in complex, with the interaction domain of SR alpha. Strikingly, the binding interface, overlaps largely with the switch 1 region of SR beta. This finding, together with additional biochemical data, shows that the eukaryotic SR is, a conditional and not an obligate heterodimer. The results suggest that, the GTP/GDP switch cycle of SR beta functions as a regulatory switch for, the receptor dimerization. We discuss the implications for the, translocation pathway.
+Protein translocation across and insertion into membranes is a process essential to all life forms. In higher eukaryotes, this process is initiated by targeting the translating ribosome to the endoplasmic reticulum via the signal recognition particle (SRP) and its membrane-associated heterodimeric receptor (SR). This targeting step is regulated by three G proteins, SRP54, SR alpha, and SR beta, which act in concert. Little is known about the regulatory role of SR beta. Here, we present the 1.7 A crystal structure of the SR beta-GTP subunit in complex with the interaction domain of SR alpha. Strikingly, the binding interface overlaps largely with the switch 1 region of SR beta. This finding, together with additional biochemical data, shows that the eukaryotic SR is a conditional and not an obligate heterodimer. The results suggest that the GTP/GDP switch cycle of SR beta functions as a regulatory switch for the receptor dimerization. We discuss the implications for the translocation pathway.
 ==About this Structure==
-NRJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with MG, GTP and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1NRJ OCA].
+NRJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=GTP:'>GTP</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NRJ OCA].
 ==Reference==
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 [[Category: transmembrane]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 22:30:28 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:09:12 2008''