1p6v
From Proteopedia
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Crystal structure of the tRNA domain of transfer-messenger RNA in complex with SmpB
Overview
Accurate translation of genetic information into protein sequence depends, on complete messenger RNA molecules. Truncated mRNAs cause synthesis of, defective proteins, and arrest ribosomes at the end of their incomplete, message. In bacteria, a hybrid RNA molecule that combines the functions of, both transfer and messenger RNAs (called tmRNA) rescues stalled ribosomes, and targets aberrant, partially synthesized, proteins for proteolytic, degradation. Here we report the 3.2-A-resolution structure of the, tRNA-like domain of tmRNA (tmRNA(Delta)) in complex with small protein B, (SmpB), a protein essential for biological functions of tmRNA. We find, that the flexible RNA molecule adopts an open L-shaped conformation and, SmpB binds to its elbow region, stabilizing the single-stranded D-loop in, an extended conformation. The most striking feature of the structure of, tmRNA(Delta) is a 90 degrees rotation of the TPsiC-arm around the helical, axis. Owing to this unusual conformation, the SmpB-tmRNA(Delta) complex, positioned into the A-site of the ribosome orients SmpB towards the small, ribosomal subunit, and directs tmRNA towards the elongation-factor binding, region of the ribosome. On the basis of this structure, we propose a model, for the binding of tmRNA on the ribosome.
About this Structure
1P6V is a Single protein structure of sequence from Aquifex aeolicus. Full crystallographic information is available from OCA.
Reference
Crystal structure of the transfer-RNA domain of transfer-messenger RNA in complex with SmpB., Gutmann S, Haebel PW, Metzinger L, Sutter M, Felden B, Ban N, Nature. 2003 Aug 7;424(6949):699-703. PMID:12904796
Page seeded by OCA on Tue Nov 20 23:31:48 2007
