Fiche publication
Date publication
décembre 2005
Journal
Nature structural & molecular biology
Auteurs
Membres identifiés du Cancéropôle Est :
Dr KLAHOLZ Bruno
,
Dr YUSUPOV Marat
,
Dr YUSUPOVA Gulnara
,
Dr SIMONETTI Angelita
Tous les auteurs :
Myasnikov AG, Marzi S, Simonetti A, Giuliodori AM, Gualerzi CO, Yusupova G, Yusupov M, Klaholz BP
Lien Pubmed
Résumé
Initiation of protein synthesis is a universally conserved event that requires initiation factors IF1, IF2 and IF3 in prokaryotes. IF2 is a GTPase essential for binding initiator transfer RNA to the 30S ribosomal subunit and recruiting the 50S subunit into the 70S initiation complex. We present two cryo-EM structures of the assembled 70S initiation complex comprising mRNA, fMet-tRNA(fMet) and IF2 with either a non-hydrolyzable GTP analog or GDP. Transition from the GTP-bound to the GDP-bound state involves substantial conformational changes of IF2 and of the entire ribosome. In the GTP analog-bound state, IF2 interacts mostly with the 30S subunit and extends to the initiator tRNA in the peptidyl (P) site, whereas in the GDP-bound state IF2 steps back and adopts a 'ready-to-leave' conformation. Our data also provide insights into the molecular mechanism guiding release of IF1 and IF3.
Mots clés
Cryoelectron Microscopy, Guanosine Diphosphate, chemistry, Guanosine Triphosphate, chemistry, Hydrolysis, Prokaryotic Initiation Factor-2, chemistry, Protein Biosynthesis, Protein Conformation, RNA, Messenger, chemistry, RNA, Transfer, Met, chemistry, Ribosomes, chemistry, Thermus thermophilus
Référence
Nat. Struct. Mol. Biol.. 2005 Dec;12(12):1145-9
