Author/Authors :
Haixiao Gao and Joachim Frank، نويسنده , , Zhihong Zhou، نويسنده , , Urmila Rawat، نويسنده , , Chenhui Huang، نويسنده , , Lamine Bouakaz، نويسنده , , Chernhoe Wang، نويسنده , , Zhihong Cheng، نويسنده , , Yuying Liu، نويسنده , , Andrey Zavialov، نويسنده , , Richard Gursky، نويسنده , , Suparna Sanyal، نويسنده , , M?ns Ehrenberg، نويسنده , , Joachim Frank، نويسنده , , Haiwei Song، نويسنده ,
Abstract :
During translation termination, class II release factor RF3 binds to the ribosome to promote rapid dissociation of a class I release factor (RF) in a GTP-dependent manner. We present the crystal structure of E. coli RF3•GDP, which has a three-domain architecture strikingly similar to the structure of EF-Tu•GTP. Biochemical data on RF3 mutants show that a surface region involving domains II and III is important for distinct steps in the action cycle of RF3. Furthermore, we present a cryo-electron microscopy (cryo-EM) structure of the posttermination ribosome bound with RF3 in the GTP form. Our data show that RF3•GTP binding induces large conformational changes in the ribosome, which break the interactions of the class I RF with both the decoding center and the GTPase-associated center of the ribosome, apparently leading to the release of the class I RF.
