2c04 | pdb_00002c04

GMPPCP complex of SRP GTPase Ffh NG Domain at ultra-high resolution

spinqualitylabelsall models 2c04, resolution 1.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2c04 is a 2 chain structure with sequence from Thermus aquaticus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.15Å Ligands: CA, GCP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SRP54_THEAQ 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 (By similarity).[HAMAP-Rule:MF_00306] 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 Two structures of the nucleotide-bound NG domain of Ffh, the GTPase subunit of the bacterial signal recognition particle (SRP), have been determined at ultrahigh resolution in similar crystal forms. One is GDP-bound and one is GMPPCP-bound. The asymmetric unit of each structure contains two protein monomers, each of which exhibits differences in nucleotide-binding conformation and occupancy. The GDP-bound Ffh NG exhibits two binding conformations in one monomer but not the other and the GMPPCP-bound protein exhibits full occupancy of the nucleotide in one monomer but only partial occupancy in the other. Thus, under the same solution conditions, each crystal reveals multiple binding states that suggest that even when nucleotide is bound its position in the Ffh NG active site is dynamic. Some differences in the positioning of the bound nucleotide may arise from differences in the crystal-packing environment and specific factors that have been identified include the relative positions of the N and G domains, small conformational changes in the P-loop, the positions of waters buried within the active site and shifts in the closing loop that packs against the guanine base. However, ;loose' binding may have biological significance in promoting facile nucleotide exchange and providing a mechanism for priming the SRP GTPase prior to its activation in its complex with the SRP receptor. Nucleotide-binding flexibility in ultrahigh-resolution structures of the SRP GTPase Ffh.,Ramirez UD, Focia PJ, Freymann DM Acta Crystallogr D Biol Crystallogr. 2008 Oct;64(Pt 10):1043-53. Epub 2008, Sep 19. PMID:18931411 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Signal recognition particle 3D structures

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