Abstract
The crystal structure of an initiation-like 70S ribosome complex containing an 8-bp Shine-Dalgarno (SD) helix was determined at 3.8-A resolution. Translation-libration-screw analysis showed that the inherent anisotropic motions of the SD helix were biased along its helical axis, suggesting that during the first step of translocation, the SD helix moves along its helical screw axis. Contacts between the SD helix and the ribosome were primarily through interactions with helices 23a, 26, and 28 of 16S rRNA. Contact with the neck (helix 28) of the 30S subunit near its hinge point suggests that formation of the SD helix could affect positioning of the head of the 30S subunit for optimal interaction with initiator tRNA. The bulged U723 in helix 23a interacts with the minor groove of the SD helix at the C1539.G-10 base pair, explaining its selective conservation in bacteria and archaea.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the National Academy of Sciences of the United States of America
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
