4v4j
From Proteopedia
Interactions and Dynamics of the Shine-Dalgarno Helix in the 70S Ribosome.
Structural highlights
FunctionRL1_THET2 Binds directly to 23S rRNA. The L1 stalk is quite mobile in the ribosome, and is involved in E site tRNA release (By similarity). Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA (By similarity). Publication Abstract from PubMedThe 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. Interactions and dynamics of the Shine Dalgarno helix in the 70S ribosome.,Korostelev A, Trakhanov S, Asahara H, Laurberg M, Lancaster L, Noller HF Proc Natl Acad Sci U S A. 2007 Oct 23;104(43):16840-3. Epub 2007 Oct 16. PMID:17940016[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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