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-Structure paper
タイトル | Visualization of release factor 3 on the ribosome during termination of protein synthesis. |
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ジャーナル・号・ページ | Nature, Vol. 427, Issue 6977, Page 862-865, Year 2004 |
掲載日 | 2004年2月26日 |
著者 | Bruno P Klaholz / Alexander G Myasnikov / Marin Van Heel / |
PubMed 要旨 | Termination of protein synthesis by the ribosome requires two release factor (RF) classes. The class II RF3 is a GTPase that removes class I RFs (RF1 or RF2) from the ribosome after release of the ...Termination of protein synthesis by the ribosome requires two release factor (RF) classes. The class II RF3 is a GTPase that removes class I RFs (RF1 or RF2) from the ribosome after release of the nascent polypeptide. RF3 in the GDP state binds to the ribosomal class I RF complex, followed by an exchange of GDP for GTP and release of the class I RF. As GTP hydrolysis triggers release of RF3 (ref. 4), we trapped RF3 on Escherichia coli ribosomes using a nonhydrolysable GTP analogue. Here we show by cryo-electron microscopy that the complex can adopt two different conformational states. In 'state 1', RF3 is pre-bound to the ribosome, whereas in 'state 2' RF3 contacts the ribosome GTPase centre. The transfer RNA molecule translocates from the peptidyl site in state 1 to the exit site in state 2. This translocation is associated with a large conformational rearrangement of the ribosome. Because state 1 seems able to accommodate simultaneously both RF3 and RF2, whose position is known from previous studies, we can infer the release mechanism of class I RFs. |
リンク | Nature / PubMed:14985767 |
手法 | EM (単粒子) |
解像度 | 17.5 - 17.9 Å |
構造データ | EMDB-1064: EMDB-1065: |
由来 |
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