Is. Gabashvili et al., Major rearrangements in the 70S ribosomal 3D structure caused by a conformational switch in 16S ribosomal RNA, EMBO J, 18(22), 1999, pp. 6501-6507
Dynamic changes in secondary structure of the 16S rRNA during the decoding
of mRNA are visualized by three-dimensional cryo-electron microscopy of the
70S ribosome, Thermodynamically unstable base pairing of the 912-910 (CUC)
nucleotides of the 16S RNA with two adjacent complementary regions at nucl
eotides 885-887 (GGG) and 888-890 (GAG) was stabilized in either of the two
states by point mutations at positions 912 (C912G) and 885 (G885U). A wave
of rearrangements can be traced arising from the switch in the three base
pairs and involving functionally important regions in both subunits of the
ribosome, This significantly affects the topography of the A-site tRNA-bind
ing region on the 30S subunit and thereby explains changes in tRNA affinity
for the ribosome and fidelity of decoding mRNA.