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4v5q

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The crystal structure of EF-Tu and G24A-tRNA-Trp bound to a near- cognate codon on the 70S ribosome

Structural highlights

4v5q is a 20 chain structure with sequence from Thermus thermophilus HB8. This structure supersedes the now removed PDB entries 2y0y, 2y0z, 2y12 and 2y13. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.1Å
Ligands:	, , , , , , , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RS2_THET8 Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit.[HAMAP-Rule:MF_00291_B]

Publication Abstract from PubMed

The ribosome converts genetic information into protein by selecting aminoacyl tRNAs whose anticodons base-pair to an mRNA codon. Mutations in the tRNA body can perturb this process and affect fidelity. The Hirsh suppressor is a well-studied tRNA(Trp) harboring a G24A mutation that allows readthrough of UGA stop codons. Here we present crystal structures of the 70S ribosome complexed with EF-Tu and aminoacyl tRNA (native tRNA(Trp), G24A tRNA(Trp) or the miscoding A9C tRNA(Trp)) bound to cognate UGG or near-cognate UGA codons, determined at 3.2-A resolution. The A9C and G24A mutations lead to miscoding by facilitating the distortion of tRNA required for decoding. A9C accomplishes this by increasing tRNA flexibility, whereas G24A allows the formation of an additional hydrogen bond that stabilizes the distortion. Our results also suggest that each native tRNA will adopt a unique conformation when delivered to the ribosome that allows accurate decoding.

How mutations in tRNA distant from the anticodon affect the fidelity of decoding.,Schmeing TM, Voorhees RM, Kelley AC, Ramakrishnan V Nat Struct Mol Biol. 2011 Apr;18(4):432-6. Epub 2011 Mar 6. PMID:21378964^[1]

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

References

↑ Schmeing TM, Voorhees RM, Kelley AC, Ramakrishnan V. How mutations in tRNA distant from the anticodon affect the fidelity of decoding. Nat Struct Mol Biol. 2011 Apr;18(4):432-6. Epub 2011 Mar 6. PMID:21378964 doi:10.1038/nsmb.2003