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2gya
From Proteopedia
Structure of the 50S subunit of a pre-translocational E. coli ribosome obtained by fitting atomic models for RNA and protein components into cryo-EM map EMD-1056
In E. coli, the SecM nascent polypeptide causes elongation arrest, while interacting with 23S RNA bases A2058 and A749-753 in the exit tunnel of the large ribosomal subunit. We compared atomic models fitted by real-space refinement into cryo-electron microscopy reconstructions of a pretranslocational and SecM-stalled E. coli ribosome complex. A cascade of RNA rearrangements propagates from the exit tunnel throughout the large subunit, affecting intersubunit bridges and tRNA positions, which in turn reorient small subunit RNA elements. Elongation arrest could result from the inhibition of mRNA.(tRNAs) translocation, E site tRNA egress, and perhaps translation factor activation at the GTPase-associated center. Our study suggests that the specific secondary and tertiary arrangement of ribosomal RNA provides the basis for internal signal transduction within the ribosome. Thus, the ribosome may itself have the ability to regulate its progression through translation by modulating its structure and consequently its receptivity to activation by cofactors.
Elongation arrest by SecM via a cascade of ribosomal RNA rearrangements., Mitra K, Schaffitzel C, Fabiola F, Chapman MS, Ban N, Frank J, Mol Cell. 2006 May 19;22(4):533-43. PMID:16713583
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
2GYA is a 28 chains structure with sequences from Escherichia coli. Full crystallographic information is available from OCA.
Reference
- Mitra K, Schaffitzel C, Fabiola F, Chapman MS, Ban N, Frank J. Elongation arrest by SecM via a cascade of ribosomal RNA rearrangements. Mol Cell. 2006 May 19;22(4):533-43. PMID:16713583
- Mitra K, Frank J. A model for co-translational translocation: ribosome-regulated nascent polypeptide translocation at the protein-conducting channel. FEBS Lett. 2006 Jun 12;580(14):3353-60. Epub 2006 May 15. PMID:16714018
Page seeded by OCA on Wed Jan 27 20:22:30 2010
