2ged: Difference between revisions

Revision as of 18:30, 21 February 2008

Signal Recognition Particle Receptor Beta-Subunit in nucleotide-free dimerized form

OverviewOverview

Protein translocation across and insertion into membranes is essential to all life forms. Signal peptide-bearing nascent polypeptide chains emerging from the ribosome are first sampled by the signal-recognition particle (SRP), then targeted to the membrane via the SRP receptor (SR), and, finally, transferred to the protein-conducting channel. In eukaryotes, this process is tightly controlled by the concerted action of three G proteins, the 54-kD subunit of SRP and the alpha- and beta-subunits of SR. We have determined the 2.2-A crystal structure of the nucleotide-free SRbeta domain. Unexpectedly, the structure is a homodimer with a highly intertwined interface made up of residues from the switch regions of the G domain. The remodeling of the switch regions does not resemble any of the known G protein switch mechanisms. Biochemical analysis confirms homodimerization in vitro, which is incompatible with SRalpha binding. The switch mechanism involves cis/trans isomerization of a strictly conserved proline, potentially implying a new layer of regulation of cotranslational transport.

About this StructureAbout this Structure

2GED is a Single protein structure of sequence from Saccharomyces cerevisiae with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Homodimerization of the G protein SRbeta in the nucleotide-free state involves proline cis/trans isomerization in the switch II region., Schwartz TU, Schmidt D, Brohawn SG, Blobel G, Proc Natl Acad Sci U S A. 2006 May 2;103(18):6823-8. Epub 2006 Apr 20. PMID:16627619

Page seeded by OCA on Thu Feb 21 17:30:50 2008

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

OCA

@@ Line 1: / Line 1: @@
-[[Image:2ged.gif|left|200px]]<br /><applet load="2ged" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2ged.gif|left|200px]]<br /><applet load="2ged" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2ged, resolution 2.20&Aring;" />
 '''Signal Recognition Particle Receptor Beta-Subunit in nucleotide-free dimerized form'''<br />
 ==Overview==
-Protein translocation across and insertion into membranes is essential to, all life forms. Signal peptide-bearing nascent polypeptide chains emerging, from the ribosome are first sampled by the signal-recognition particle, (SRP), then targeted to the membrane via the SRP receptor (SR), and, finally, transferred to the protein-conducting channel. In eukaryotes, this process is tightly controlled by the concerted action of three G, proteins, the 54-kD subunit of SRP and the alpha- and beta-subunits of SR., We have determined the 2.2-A crystal structure of the nucleotide-free, SRbeta domain. Unexpectedly, the structure is a homodimer with a highly, intertwined interface made up of residues from the switch regions of the G, domain. The remodeling of the switch regions does not resemble any of the, known G protein switch mechanisms. Biochemical analysis confirms, homodimerization in vitro, which is incompatible with SRalpha binding. The, switch mechanism involves cis/trans isomerization of a strictly conserved, proline, potentially implying a new layer of regulation of cotranslational, transport.
+Protein translocation across and insertion into membranes is essential to all life forms. Signal peptide-bearing nascent polypeptide chains emerging from the ribosome are first sampled by the signal-recognition particle (SRP), then targeted to the membrane via the SRP receptor (SR), and, finally, transferred to the protein-conducting channel. In eukaryotes, this process is tightly controlled by the concerted action of three G proteins, the 54-kD subunit of SRP and the alpha- and beta-subunits of SR. We have determined the 2.2-A crystal structure of the nucleotide-free SRbeta domain. Unexpectedly, the structure is a homodimer with a highly intertwined interface made up of residues from the switch regions of the G domain. The remodeling of the switch regions does not resemble any of the known G protein switch mechanisms. Biochemical analysis confirms homodimerization in vitro, which is incompatible with SRalpha binding. The switch mechanism involves cis/trans isomerization of a strictly conserved proline, potentially implying a new layer of regulation of cotranslational transport.
 ==About this Structure==
-GED is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2GED OCA].
+GED is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GED OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Schmidt, D.]]
-[[Category: Schwartz, T.U.]]
+[[Category: Schwartz, T U.]]
 [[Category: SO4]]
 [[Category: circular permutation]]
@@ Line 22: / Line 22: @@
 [[Category: signal recognition particle]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 11:09:11 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:30:50 2008''