1l4s | pdb_00001l4s
Solution structure of ribosome associated factor Y
Structural highlights
Function[RAIA_ECOLI] During stationary phase, prevents 70S dimer formation, probably in order to regulate translation efficiency during transition between the exponential and the stationary phases. In addition, during environmental stress such as cold shock or excessive cell density at stationary phase, stabilizes the 70S ribosome against dissociation, inhibits translation initiation and increase translation accuracy. When normal growth conditions are restored, is quickly released from the ribosome. Inhibits translation initiation by blocking the A-site (aminoacyl-tRNA site) and P-site (peptidyl-tRNA site) of the ribosome. Counteracts miscoding (translation errors) particularly efficiently at magnesium concentrations close to those observed in vivo but less efficiently at higher concentrations. Counteraction of miscoding was shown to be stronger than inhibition of translation, suggesting that the former activity could be the main function of RaiA in vivo.[1] [2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedEscherichia coli protein Y (pY) binds to the small ribosomal subunit and stabilizes ribosomes against dissociation when bacteria experience environmental stress. pY inhibits translation in vitro, most probably by interfering with the binding of the aminoacyl-tRNA to the ribosomal A site. Such a translational arrest may mediate overall adaptation of cells to environmental conditions. We have determined the 3D solution structure of a 112-residue pY and have studied its backbone dynamic by NMR spectroscopy. The structure has a betaalphabetabetabetaalpha topology and represents a compact two-layered sandwich of two nearly parallel alpha helices packed against the same side of a four-stranded beta sheet. The 23 C-terminal residues of the protein are disordered. Long-range angular constraints provided by residual dipolar coupling data proved critical for precisely defining the position of helix 1. Our data establish that the C-terminal region of helix 1 and the loop linking this helix with strand beta2 show significant conformational exchange in the ms- micro s time scale, which may have relevance to the interaction of pY with ribosomal subunits. Distribution of the conserved residues on the protein surface highlights a positively charged region towards the C-terminal segments of both alpha helices, which most probably constitutes an RNA binding site. The observed betaalphabetabetabetaalpha topology of pY resembles the alphabetabetabetaalpha topology of double-stranded RNA-binding domains, despite limited sequence similarity. It appears probable that functional properties of pY are not identical to those of dsRBDs, as the postulated RNA-binding site in pY does not coincide with the RNA-binding surface of the dsRBDs. Ribosome-associated factor Y adopts a fold resembling a double-stranded RNA binding domain scaffold.,Ye K, Serganov A, Hu W, Garber M, Patel DJ Eur J Biochem. 2002 Nov;269(21):5182-91. PMID:12392550[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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