Ribosomal protein L5 has a highly twisted concave surface and flexible arms responsible for rRNA binding

Citation
T. Nakashima et al., Ribosomal protein L5 has a highly twisted concave surface and flexible arms responsible for rRNA binding, RNA, 7(5), 2001, pp. 692-701
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
RNA-A PUBLICATION OF THE RNA SOCIETY
ISSN journal
1355-8382 → ACNP
Volume
7
Issue
5
Year of publication
2001
Pages
692 - 701
Database
ISI
SICI code
1355-8382(200105)7:5<692:RPLHAH>2.0.ZU;2-C
Abstract
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 stea rothermophilus has been determined at 1.8 Angstrom resolution. The molecule consists of a five-stranded antiparallel beta -sheet and four alpha -helic es, which fold in a way that is topologically similar to the ribonucleoprot ein (RNP) domain. The molecular shape and electrostatic representation sugg est that the concave surface and loop regions are involved in 5S rRNA bindi ng. To identify amino acid residues responsible for 5S rRNA binding, we mad e use of Ala-scanning mutagenesis of evolutionarily conserved amino acids o ccurring in the beta -strands and loop regions. The mutations of Asn37 at t he beta1-strand and Gln63 at the loop between helix 2 and beta3-strand as w ell as that of Phe77 at the tip of the loop structure between the beta2- an d beta3-strands caused a significant reduction in 5S rRNA binding. In addit ion, the mutations of Thr90 on the beta3-strand and Ile141 and Asp144 at th e loop between beta4- and beta5-strands moderately reduced the 5S rRNA-bind ing affinity. Comparison of these results with the more recently analyzed s tructure 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.