1MFQ
Crystal Structure Analysis of a Ternary S-Domain Complex of Human Signal Recognition Particle
Summary for 1MFQ
| Entry DOI | 10.2210/pdb1mfq/pdb |
| Descriptor | 7S RNA of human SRP, signal recognition particle 19kDa protein, signal recognition particle 54kDa protein, ... (6 entities in total) |
| Functional Keywords | rna-protein complex, a-minor motif, 3-helix junction, signaling protein-rna complex, signaling protein/rna |
| Biological source | Homo sapiens (human) More |
| Cellular location | Cytoplasm: P09132 Nucleus speckle: P61011 |
| Total number of polymer chains | 3 |
| Total formula weight | 69053.88 |
| Authors | Kuglstatter, A.,Oubridge, C.,Nagai, K. (deposition date: 2002-08-13, release date: 2002-09-20, Last modification date: 2024-02-14) |
| Primary citation | Kuglstatter, A.,Oubridge, C.,Nagai, K. Induced structural changes of 7SL RNA during the assembly of human signal recognition particle Nat.Struct.Biol., 9:740-744, 2002 Cited by PubMed Abstract: The eukaryotic signal recognition particle (SRP) is a cytoplasmic ribonucleoprotein particle that targets secretory and membrane proteins to the endoplasmic reticulum. The binding of SRP54 to the S domain of 7SL RNA is highly dependent on SRP19. Here we present the crystal structure of a human SRP ternary complex consisting of SRP19, the M domain of SRP54 and the S domain of 7SL RNA. Upon binding of the M domain of SRP54 to the 7SL RNA-SRP19 complex, the asymmetric loop of helix 8 in 7SL RNA collapses. The bases of the four nucleotides in the long strand of the asymmetric loop continuously stack and interact with the M domain, whereas the two adenines in the short strand flip out and form two A-minor motifs with helix 6. This stabilizing interaction is only possible when helix 6 has been positioned parallel to helix 8 by the prior binding of SRP19 to the tetraloops of helices 6 and 8. Hence, the crystal structure of the ternary complex suggests why SRP19 is necessary for the stable binding of SRP54 to the S domain RNA. PubMed: 12244299DOI: 10.1038/nsb843 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.1 Å) |
Structure validation
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