Major centers of motion in the large ribosomal RNAs



Journal Title

Journal ISSN

Volume Title


Nucleic Acids Research


Major centers of motion in the rRNAs of Thermus thermophilus are identified by alignment of crystal structures of EF-G bound and EF-G unbound ribosomal subunits. Small rigid helices upstream of these ‘pivots’ are aligned, thereby decoupling their motion from global rearrangements. Of the 21 pivots found, six are observed in the large subunit rRNA and 15 in the small subunit rRNA. Although the magnitudes of motion differ, with only minor exceptions equivalent pivots are seen in comparisons of Escherichia coli structures and one Saccharomyces cerevisiae structure pair. The pivoting positions are typically associated with structurally weak motifs such as noncanonical, primarily U-G pairs, bulge loops and threeway junctions. Each pivot is typically in direct physical contact with at least one other in the set and often several others. Moving helixes include rRNA segments in contact with the tRNA, intersubunit bridges and helices 28, 32 and 34 of the small subunit. These helices are envisioned to form a network. EF-G rearrangement would then provide directional control of this network propagating motion from the tRNA to the intersubunit bridges to the head swivel or along the same path backward.





Copyright 2015 Nucleic acids research. Recommended citation: Paci, Maxim, and George E. Fox. "Major centers of motion in the large ribosomal RNAs." Nucleic acids research 43, no. 9 (2015): 4640-4649. DOI: 10.1093/nar/gkv289. URL: Reproduced in accordance with the original publisher’s licensing terms and with permission from the author(s).