2fh5
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /> <applet load="2fh5" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fh5, resolution 2.45Å" /> '''The Structure of th...)
Next diff →
Revision as of 19:58, 12 November 2007
|
The Structure of the Mammalian SRP Receptor
Overview
The eukaryotic signal recognition particle (SRP) and its receptor (SR), play a central role in co-translational targeting of secretory and, membrane proteins to the endoplasmic reticulum. The SR is a heterodimeric, complex assembled by the two GTPases SRalpha and SRbeta, which is, membrane-anchored. Here we present the 2.45-A structure of mammalian, SRbeta in its Mg2+ GTP-bound state in complex with the minimal binding, domain of SRalpha termed SRX. SRbeta is a member of the Ras-GTPase, superfamily closely related to Arf and Sar1, while SRX belongs to the, SNARE-like superfamily with a fold also known as longin domain. SRX binds, to the P loop and the switch regions of SRbeta-GTP. The binding mode and, structural similarity with other GTPase-effector complexes suggests a, co-GAP (GTPase-activating protein) function for SRX. Comparison with the, homologous yeast structure and other longin domains reveals a conserved, adjustable hydrophobic surface within SRX which is of central importance, for the SRbeta-GTP:SRX interface. A helix swap in SRX results in the, formation of a dimer in the crystal structure. Based on structural, conservation we present the SRbeta-GTP:SRX structure as a prototype for, conserved interactions in a variety of GTPase regulated targeting events, occurring at endomembranes.
About this Structure
2FH5 is a Protein complex structure of sequences from Homo sapiens and Mus musculus with MG and GTP as ligands. Full crystallographic information is available from OCA.
Reference
The structure of the mammalian signal recognition particle (SRP) receptor as prototype for the interaction of small GTPases with Longin domains., Schlenker O, Hendricks A, Sinning I, Wild K, J Biol Chem. 2006 Mar 31;281(13):8898-906. Epub 2006 Jan 26. PMID:16439358
Page seeded by OCA on Mon Nov 12 22:05:20 2007
