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Cryo‐EM reveals an active role for aminoacyl‐tRNA in the accommodation process
Author(s) -
Valle Mikel,
Sengupta Jayati,
Swami Neil K.,
Grassucci Robert A.,
Burkhardt Nils,
Nierhaus Knud H.,
Agrawal Rajendra K.,
Frank Joachim
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdf326
Subject(s) - ef tu , transfer rna , biology , ribosome , ternary complex , t arm , gtpase , p site , guanosine triphosphate , aminoacyl trna , a site , protein biosynthesis , biochemistry , protein subunit , shine dalgarno sequence , gtp' , thermus thermophilus , rna , escherichia coli , binding site , enzyme , gene
During the elongation cycle of protein biosynthesis, the specific amino acid coded for by the mRNA is delivered by a complex that is comprised of the cognate aminoacyl‐tRNA, elongation factor Tu and GTP. As this ternary complex binds to the ribosome, the anticodon end of the tRNA reaches the decoding center in the 30S subunit. Here we present the cryo‐ electron microscopy (EM) study of an Escherichia coli 70S ribosome‐bound ternary complex stalled with an antibiotic, kirromycin. In the cryo‐EM map the anticodon arm of the tRNA presents a new conformation that appears to facilitate the initial codon–anticodon interaction. Furthermore, the elbow region of the tRNA is seen to contact the GTPase‐associated center on the 50S subunit of the ribosome, suggesting an active role of the tRNA in the transmission of the signal prompting the GTP hydrolysis upon codon recognition.