1iq4
5S-RRNA BINDING RIBOSOMAL PROTEIN L5 FROM BACILLUS STEAROTHERMOPHILUS
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OverviewOverview
Ribosomal protein L5 is a 5S rRNA binding protein in the large subunit and, plays an essential role in the promotion of a particular conformation of, 5S rRNA. The crystal structure of the ribosomal protein L5 from Bacillus, stearothermophilus has been determined at 1.8 A resolution. The molecule, consists of a five-stranded antiparallel beta-sheet and four, alpha-helices, which fold in a way that is topologically similar to the, ribonucleoprotein (RNP) domain. The molecular shape and electrostatic, representation suggest that the concave surface and loop regions are, involved in 5S rRNA binding. To identify amino acid residues responsible, for 5S rRNA binding, we made use of Ala-scanning mutagenesis of, evolutionarily conserved amino acids occurring in the beta-strands and, loop regions. The mutations of Asn37 at the beta1-strand and Gln63 at the, loop between helix 2 and beta3-strand as well as that of Phe77 at the tip, of the loop structure between the beta2- and beta3-strands caused a, significant reduction in 5S rRNA binding. In addition, the mutations of, Thr90 on the beta3-strand and Ile141 and Asp144 at the loop between beta4-, and beta5-strands moderately reduced the 5S rRNA-binding affinity., Comparison of these results with the more recently analyzed structure of, the 50S subunit from Haloarcula marismortui suggests that there are, significant differences in the structure at N- and C-terminal regions and, probably in the 5S rRNA binding.
About this StructureAbout this Structure
1IQ4 is a Single protein structure of sequence from Geobacillus stearothermophilus. Full crystallographic information is available from OCA.
ReferenceReference
Ribosomal protein L5 has a highly twisted concave surface and flexible arms responsible for rRNA binding., Nakashima T, Yao M, Kawamura S, Iwasaki K, Kimura M, Tanaka I, RNA. 2001 May;7(5):692-701. PMID:11350033
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