1. Cryo-EM reveals an active role for aminoacyl-tRNA in the accommodation process.
- Author
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Valle M, Sengupta J, Swami NK, Grassucci RA, Burkhardt N, Nierhaus KH, Agrawal RK, and Frank J
- Subjects
- Anticodon genetics, Codon genetics, Escherichia coli chemistry, Escherichia coli Proteins chemistry, Escherichia coli Proteins ultrastructure, Guanosine Diphosphate chemistry, Guanosine Triphosphate metabolism, Image Processing, Computer-Assisted, Macromolecular Substances, Models, Molecular, Nucleic Acid Conformation, Peptide Elongation Factor Tu chemistry, Peptide Elongation Factor Tu ultrastructure, Protein Conformation, Pyridones pharmacology, RNA, Transfer chemistry, RNA, Transfer, Amino Acyl chemistry, RNA, Transfer, Amino Acyl metabolism, RNA, Transfer, Amino Acyl ultrastructure, RNA, Transfer, Phe chemistry, RNA, Transfer, Phe metabolism, Ribosomes chemistry, Ribosomes drug effects, Structure-Activity Relationship, Cryoelectron Microscopy, Peptide Chain Elongation, Translational, RNA, Transfer, Amino Acyl physiology, Ribosomes ultrastructure
- Abstract
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.
- Published
- 2002
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