4f7u

From Proteopedia

(Difference between revisions)

Revision as of 20:44, 24 December 2014

Macromolecular Machine 6

Structural highlights

4f7u is a 12 chain structure with sequence from Drosophila melanogaster, Lk3 transgenic mice, Mus musculus and Xenopus laevis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Gene:	Snrpd1 (Mus musculus), Snrpd2 (Mus musculus), Snrpe (Mus musculus), snrpf (Xenopus laevis), Snrpg (Mus musculus), CG4924, icln (Drosophila melanogaster), icln, CG4924 (LK3 transgenic mice)
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[Q9U3W1_DROME] Chaperone that regulates the assembly of spliceosomal U1, U2, U4 and U5 small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome. Thereby, plays an important role in the splicing of cellular pre-mRNAs. Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP. In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. Dissociation by the SMN complex of CLNS1A from the trapped Sm proteins and their transfer to an SMN-Sm complex triggers the assembly of core snRNPs and their transport to the nucleus (By similarity).

Publication Abstract from PubMed

Small nuclear ribonucleoproteins (snRNPs) represent key constituents of major and minor spliceosomes. snRNPs contain a common core, composed of seven Sm proteins bound to snRNA, which forms in a step-wise and factor-mediated reaction. The assembly chaperone pICln initially mediates the formation of an otherwise unstable pentameric Sm protein unit. This so-called 6S complex docks subsequently onto the SMN complex, which removes pICln and enables the transfer of pre-assembled Sm proteins onto snRNA. X-ray crystallography and electron microscopy was used to investigate the structural basis of snRNP assembly. The 6S complex structure identifies pICln as an Sm protein mimic, which enables the topological organization of the Sm pentamer in a closed ring. A second structure of 6S bound to the SMN complex components SMN and Gemin2 uncovers a plausible mechanism of pICln elimination and Sm protein activation for snRNA binding. Our studies reveal how assembly factors facilitate formation of RNA-protein complexes in vivo.

Structural Basis of Assembly Chaperone- Mediated snRNP Formation.,Grimm C, Chari A, Pelz JP, Kuper J, Kisker C, Diederichs K, Stark H, Schindelin H, Fischer U Mol Cell. 2013 Jan 15. pii: S1097-2765(12)01018-0. doi:, 10.1016/j.molcel.2012.12.009. PMID:23333303^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Grimm C, Chari A, Pelz JP, Kuper J, Kisker C, Diederichs K, Stark H, Schindelin H, Fischer U. Structural Basis of Assembly Chaperone- Mediated snRNP Formation. Mol Cell. 2013 Jan 15. pii: S1097-2765(12)01018-0. doi:, 10.1016/j.molcel.2012.12.009. PMID:23333303 doi:http://dx.doi.org/10.1016/j.molcel.2012.12.009

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4f7u"

@@ Line 7: / Line 7: @@
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4f7u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4f7u OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4f7u RCSB], [http://www.ebi.ac.uk/pdbsum/4f7u PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/Q9U3W1_DROME Q9U3W1_DROME]] Chaperone that regulates the assembly of spliceosomal U1, U2, U4 and U5 small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome. Thereby, plays an important role in the splicing of cellular pre-mRNAs. Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP. In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. Dissociation by the SMN complex of CLNS1A from the trapped Sm proteins and their transfer to an SMN-Sm complex triggers the assembly of core snRNPs and their transport to the nucleus (By similarity).
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==

4f7u

From Proteopedia

Revision as of 20:44, 24 December 2014

Macromolecular Machine 6

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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