2nnw
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The Nop56/58-fibrillarin heterocomplex is a core protein complex of the | + | The Nop56/58-fibrillarin heterocomplex is a core protein complex of the box C/D ribonucleoprotein particles that modify and process ribosomal RNAs. The previous crystal structure of the Archaeoglobus fulgidus complex revealed a symmetric dimer of two Nop56/58-fibrillarin complexes linked by the coiled-coil domains of the Nop56/68 proteins. However, because the A. fulgidus Nop56/58 protein lacks some domains found in most other species, it was thought that the bipartite architecture of the heterocomplex was not likely a general phenomenon. Here we report the crystal structure of the Nop56/58-fibrillarin complex bound with methylation cofactor, S-adenosyl-L-methionine from Pyrococcus furiosus, at 2.7 A. The new complex confirms the generality of the previously observed bipartite arrangement. In addition however, the conformation of Nop56/58 in the new structure differs substantially from that in the earlier structure. The distinct conformations of Nop56/58 suggest potential flexibility in Nop56/58. Computational normal mode analysis supports this view. Importantly, fibrillarin is repositioned within the two complexes. We propose that hinge motion within Nop56/58 has important implications for the possibility of simultaneously positioning two catalytic sites at the two target sites of a bipartite box C/D guide RNA. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Alternative | + | Alternative conformations of the archaeal Nop56/58-fibrillarin complex imply flexibility in box C/D RNPs., Oruganti S, Zhang Y, Li H, Robinson H, Terns MP, Terns RM, Yang W, Li H, J Mol Biol. 2007 Aug 31;371(5):1141-50. Epub 2007 Jun 15. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17617422 17617422] |
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Pyrococcus furiosus]] | [[Category: Pyrococcus furiosus]] | ||
[[Category: Li, H.]] | [[Category: Li, H.]] | ||
[[Category: Oruganti, S.]] | [[Category: Oruganti, S.]] | ||
| - | [[Category: Terns, M | + | [[Category: Terns, M P.]] |
[[Category: Terns, R.]] | [[Category: Terns, R.]] | ||
[[Category: Zhang, Y.]] | [[Category: Zhang, Y.]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:08:52 2008'' |
Revision as of 16:08, 21 February 2008
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Alternative conformations of Nop56/58-fibrillarin complex and implication for induced-fit assenly of box C/D RNPs
Overview
The Nop56/58-fibrillarin heterocomplex is a core protein complex of the box C/D ribonucleoprotein particles that modify and process ribosomal RNAs. The previous crystal structure of the Archaeoglobus fulgidus complex revealed a symmetric dimer of two Nop56/58-fibrillarin complexes linked by the coiled-coil domains of the Nop56/68 proteins. However, because the A. fulgidus Nop56/58 protein lacks some domains found in most other species, it was thought that the bipartite architecture of the heterocomplex was not likely a general phenomenon. Here we report the crystal structure of the Nop56/58-fibrillarin complex bound with methylation cofactor, S-adenosyl-L-methionine from Pyrococcus furiosus, at 2.7 A. The new complex confirms the generality of the previously observed bipartite arrangement. In addition however, the conformation of Nop56/58 in the new structure differs substantially from that in the earlier structure. The distinct conformations of Nop56/58 suggest potential flexibility in Nop56/58. Computational normal mode analysis supports this view. Importantly, fibrillarin is repositioned within the two complexes. We propose that hinge motion within Nop56/58 has important implications for the possibility of simultaneously positioning two catalytic sites at the two target sites of a bipartite box C/D guide RNA.
About this Structure
2NNW is a Protein complex structure of sequences from Pyrococcus furiosus. Full crystallographic information is available from OCA.
Reference
Alternative conformations of the archaeal Nop56/58-fibrillarin complex imply flexibility in box C/D RNPs., Oruganti S, Zhang Y, Li H, Robinson H, Terns MP, Terns RM, Yang W, Li H, J Mol Biol. 2007 Aug 31;371(5):1141-50. Epub 2007 Jun 15. PMID:17617422
Page seeded by OCA on Thu Feb 21 18:08:52 2008
