The solution structure of ribosomal protein S4 ?41 reveals two subdomains and a positively charged surface that may interact with RNA.

Autor: Markus, Michelle A., Gerstner, Resi B., Draper, David E., Torchia, Dennis A.
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Zdroj: EMBO Journal; 8/15/98, Vol. 17 Issue 16, p4559-4571, 13p
Abstrakt: S4 is one of the first proteins to bind to 16S RNA during assembly of the prokaryotic ribosome. Residues 43–200 of S4 from Bacillus stearothermophilus (S4 Δ41) bind specifically to both 16S rRNA and to a pseudoknot within the α operon mRNA. As a first step toward understanding how S4 recognizes and organizes RNA, we have solved the structure of ΔS4 41 in solution by multidimensional heteronuclear nuclear magnetic resonance spectroscopy. The fold consists of two globular subdomains, one comprised of four helices and the other comprised of a five-stranded antiparallel β-sheet and three helices. Although cross-linking studies suggest that residues between helices α2 and α3 are close to RNA, the concentration of positive charge along the crevice between the two subdomains suggests that this could be an RNA-binding site. In contrast to the L11 RNA-binding domain studied previously, S4 Δ41 shows no fast local motions, suggesting that it has less capacity for refolding to fit RNA. The independently determined crystal structure of S4 Δ41 shows similar features, although there is small rotation of the subdomains compared with the solution structure. The relative orientation of the subdomains in solution will be verified with further study. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index