2FH5
The Structure of the Mammalian SRP Receptor
Summary for 2FH5
| Entry DOI | 10.2210/pdb2fh5/pdb |
| Descriptor | Signal recognition particle receptor alpha subunit, Signal recognition particle receptor beta subunit, MAGNESIUM ION, ... (5 entities in total) |
| Functional Keywords | endomembrane targeting, gtpase, gap, longin domain, sedl, signal recognition particle receptor, transport protein |
| Biological source | Homo sapiens (human) More |
| Cellular location | Endoplasmic reticulum membrane; Peripheral membrane protein: P08240 Endoplasmic reticulum membrane; Single-pass membrane protein (By similarity): P47758 |
| Total number of polymer chains | 2 |
| Total formula weight | 45413.98 |
| Authors | Schlenker, O.,Wild, K.,Sinning, I. (deposition date: 2005-12-23, release date: 2006-01-31, Last modification date: 2024-10-30) |
| Primary citation | Schlenker, O.,Hendricks, A.,Sinning, I.,Wild, K. The structure of the mammalian signal recognition particle (SRP) receptor as prototype for the interaction of small GTPases with Longin domains. J.Biol.Chem., 281:8898-8906, 2006 Cited by PubMed Abstract: 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. PubMed: 16439358DOI: 10.1074/jbc.M512415200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.45 Å) |
Structure validation
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