1iq4
From Proteopedia
5S-RRNA BINDING RIBOSOMAL PROTEIN L5 FROM BACILLUS STEAROTHERMOPHILUS
Structural highlights
Function[RL5_BACST] This is 1 of the proteins that binds and probably mediates the attachment of the 5S RNA into the large ribosomal subunit, where it forms part of the central protuberance. In the 70S ribosome it contacts protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement. Contacts the P site tRNA; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs (By similarity).[HAMAP-Rule:MF_01333_B] 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 PubMedRibosomal 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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