TY - JOUR
T1 - The Real-Time Path of Translation Factor IF3 onto and off the Ribosome
AU - Fabbretti, Attilio
AU - Pon, Cynthia L.
AU - Hennelly, Scott P.
AU - Hill, Walter E.
AU - Lodmell, J. Stephen
AU - Gualerzi, Claudio O.
N1 - Funding Information:
The financial support of Progetti di Ricerca di Interesse Nazionale 2005 grants of the Italian Ministero dell'Istruzione dell'Universita e della Ricerca to C.O.G. and C.L.P. is gratefully acknowledged.
PY - 2007/1/26
Y1 - 2007/1/26
N2 - Translation initiation factor IF3 is an essential bacterial protein, consisting of two domains (IF3C and IF3N) separated by a linker, which interferes with ribosomal subunit association, promotes codon-anticodon interaction in the P site, and ensures translation initiation fidelity. Using time-resolved chemical probing, we followed the dynamic binding path of IF3 on the 30S subunit and its release upon 30S-50S association. During binding, IF3 first contacts the platform (near G700) of the 30S subunit with the C domain and then the P-decoding region (near A790) with its N domain. At equilibrium, attained within less than a second, both sites are protected, but before reaching binding equilibrium, IF3 causes additional transient perturbations of both the platform edge and the solvent side of the subunit. Upon 30S-50S association, IF3 dissociates concomitantly with the establishment of the 30S-50S bridges, following the reverse path of its binding with the IF3N-A790 interaction being lost before the IF3C-G700 interaction.
AB - Translation initiation factor IF3 is an essential bacterial protein, consisting of two domains (IF3C and IF3N) separated by a linker, which interferes with ribosomal subunit association, promotes codon-anticodon interaction in the P site, and ensures translation initiation fidelity. Using time-resolved chemical probing, we followed the dynamic binding path of IF3 on the 30S subunit and its release upon 30S-50S association. During binding, IF3 first contacts the platform (near G700) of the 30S subunit with the C domain and then the P-decoding region (near A790) with its N domain. At equilibrium, attained within less than a second, both sites are protected, but before reaching binding equilibrium, IF3 causes additional transient perturbations of both the platform edge and the solvent side of the subunit. Upon 30S-50S association, IF3 dissociates concomitantly with the establishment of the 30S-50S bridges, following the reverse path of its binding with the IF3N-A790 interaction being lost before the IF3C-G700 interaction.
KW - RNA
UR - http://www.scopus.com/inward/record.url?scp=33846208718&partnerID=8YFLogxK
U2 - 10.1016/j.molcel.2006.12.011
DO - 10.1016/j.molcel.2006.12.011
M3 - Article
C2 - 17244535
AN - SCOPUS:33846208718
SN - 1097-2765
VL - 25
SP - 285
EP - 296
JO - Molecular Cell
JF - Molecular Cell
IS - 2
ER -