Functional Conformations of the L11-ribosomal Rna Complex Revealed by Correlative Analysis of Cryo-em and Molecular Dynamics Simulations.
From: Wadsworth Center, Empire State Plaza, Albany, New York 12201-0509, USA.
RNA (New York, N.Y.)
- Publish Date: Jul 2006
- ISSN: 1355-8382
- Volume: 12
- Issue: 7
- Pages: 1240-53
- Medium: Print
- Language: English
- Citation (JAMA): Li Wen, Sengupta Jayati, Rath Bimal K, et al. Functional Conformations of the L11-ribosomal Rna Complex Revealed by Correlative Analysis of Cryo-em and Molecular Dynamics Simulations.. RNA Jul 2006;12:1240-53
Abstract
The interaction between the GTPase-associated center (GAC) and the aminoacyl-tRNA.EF-Tu.GTP ternary complex is of crucial importance in the dynamic process of decoding and tRNA accommodation. The GAC includes protein L11 and helices 43-44 of 23S rRNA (referred to as L11-rRNA complex). In this study, a method of fitting based on a systematic comparison between cryo-electron microscopy (cryo-EM) density maps and structures obtained by molecular dynamics simulations has been developed. This method has led to the finding of atomic models of the GAC that fit the EM maps with much improved cross-correlation coefficients compared with the fitting of the X-ray structure. Two types of conformations of the L11-rRNA complex, produced by the simulations, match the cryo-EM maps representing the states either bound or unbound to the aa-tRNA.EF-Tu.GTP ternary complex. In the bound state, the N-terminal domain of L11 is extended from its position in the crystal structure, and the base of nucleotide A1067 in the 23S ribosomal RNA is flipped out. This position of the base allows the RNA to reach the elbow region of the aminoacyl-tRNA when the latter is bound in the A/T site. In the unbound state, the N-terminal domain of L11 is rotated only slightly, and A1067 of the RNA is flipped back into the less-solvent-exposed position, as in the crystal structure. By matching our experimental cryo-EM maps with much improved cross-correlation coefficients compared to the crystal structure, these two conformations prove to be strong candidates of the two functional states.
Mesh Headings (Keywords): Amino Acid Sequence, Binding Sites, Calorimetry, Computer Simulation, Cryoelectron Microscopy, GTP Phosphohydrolases, Models, Molecular, Molecular Sequence Data, Nucleic Acid Conformation, RNA, Ribosomal, 23S, Ribosomal Proteins, Software
Check for Full Text / PubMed Unique Identifier (PMID): 16682558
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.