Molecular insights into protein synthesis with proline residues.
Fiche publication
Date publication
décembre 2016
Journal
EMBO reports
Auteurs
Membres identifiés du Cancéropôle Est :
Dr YUSUPOV Marat, Dr YUSUPOVA Gulnara
Tous les auteurs :
Melnikov S, Mailliot J, Rigger L, Neuner S, Shin BS, Yusupova G, Dever TE, Micura R, Yusupov M
Lien Pubmed
Résumé
Proline is an amino acid with a unique cyclic structure that facilitates the folding of many proteins, but also impedes the rate of peptide bond formation by the ribosome. As a ribosome substrate, proline reacts markedly slower when compared with other amino acids both as a donor and as an acceptor of the nascent peptide. Furthermore, synthesis of peptides with consecutive proline residues triggers ribosome stalling. Here, we report crystal structures of the eukaryotic ribosome bound to analogs of mono- and diprolyl-tRNAs. These structures provide a high-resolution insight into unique properties of proline as a ribosome substrate. They show that the cyclic structure of proline residue prevents proline positioning in the amino acid binding pocket and affects the nascent peptide chain position in the ribosomal peptide exit tunnel. These observations extend current knowledge of the protein synthesis mechanism. They also revise an old dogma that amino acids bind the ribosomal active site in a uniform way by showing that proline has a binding mode distinct from other amino acids.
Mots clés
Amino Acid Sequence, Crystallography, X-Ray, Escherichia coli, genetics, Models, Molecular, Peptides, chemistry, Proline, chemistry, Protein Binding, Protein Biosynthesis, RNA, Transfer, Pro, metabolism, Ribosomes, chemistry
Référence
EMBO Rep.. 2016 12;17(12):1776-1784