Alernative Conformations of the Archaeal Nop56/58-Fibrillarin Complex Imply Flexibility in Box C/D RNPs

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Journal of Molecular Biology

DOI:https://doi.org/10.1016/j.jmb.2007.06.029· OSTI ID:959740

Oruganti, S; Zhang, Y; Li, H; Robinson, H; Terns, M; Terns, R; Yang, W; Li, H

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 Angstroms. 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.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959740
• Report Number(s): BNL--82726-2009-JA
• Journal Information: Journal of Molecular Biology, Journal Name: Journal of Molecular Biology Journal Issue: 5 Vol. 371; ISSN JMOBAK; ISSN 0022-2836
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARCHITECTURE
CRYSTAL STRUCTURE
DIMERS
FLEXIBILITY
METHYLATION
NORMAL-MODE ANALYSIS
POSITIONING
PROTEINS
RIBOSOMAL RNA
RNA
TARGETS
national synchrotron light source