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4lt8

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Crystal Structure of tRNA Proline (CGG) Bound to Codon CCC-G on the Ribosome

Structural highlights

4lt8 is a 20 chain structure with sequence from Thermus thermophilus HB8. This structure supersedes the now removed PDB entries 1vxp, 1vxq, 1vxs and 1vxt. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RS12_THET8 With S4 and S5 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_00403_B] Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit.[HAMAP-Rule:MF_00403_B]

Publication Abstract from PubMed

Maintenance of the correct reading frame on the ribosome is essential for accurate protein synthesis. Here, we report structures of the 70S ribosome bound to frameshift suppressor tRNASufA6 and N1-methylguanosine at position 37 (m1G37) modification-deficient anticodon stem loopPro, both of which cause the ribosome to decode 4 rather than 3 nucleotides, resulting in a +1 reading frame. Our results reveal that decoding at +1 suppressible codons causes suppressor tRNASufA6 to undergo a rearrangement of its 5' stem that destabilizes U32, thereby disrupting the conserved U32-A38 base pair. Unexpectedly, the removal of the m1G37 modification of tRNAPro also disrupts U32-A38 pairing in a structurally analogous manner. The lack of U32-A38 pairing provides a structural correlation between the transition from canonical translation and a +1 reading of the mRNA. Our structures clarify the molecular mechanism behind suppressor tRNA-induced +1 frameshifting and advance our understanding of the role played by the ribosome in maintaining the correct translational reading frame.

Structural insights into +1 frameshifting promoted by expanded or modification-deficient anticodon stem loops.,Maehigashi T, Dunkle JA, Miles SJ, Dunham CM Proc Natl Acad Sci U S A. 2014 Aug 15. pii: 201409436. PMID:25128388^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Maehigashi T, Dunkle JA, Miles SJ, Dunham CM. Structural insights into +1 frameshifting promoted by expanded or modification-deficient anticodon stem loops. Proc Natl Acad Sci U S A. 2014 Aug 15. pii: 201409436. PMID:25128388 doi:http://dx.doi.org/10.1073/pnas.1409436111