+検索条件
-Structure paper
タイトル | Mechanisms of ribosome stalling by SecM at multiple elongation steps. |
---|---|
ジャーナル・号・ページ | Elife, Vol. 4, Year 2015 |
掲載日 | 2015年12月14日 |
![]() | Jun Zhang / Xijiang Pan / Kaige Yan / Shan Sun / Ning Gao / Sen-Fang Sui / ![]() |
PubMed 要旨 | Regulation of translating ribosomes is a major component of gene expression control network. In Escherichia coli, ribosome stalling by the C-terminal arrest sequence of SecM regulates the SecA- ...Regulation of translating ribosomes is a major component of gene expression control network. In Escherichia coli, ribosome stalling by the C-terminal arrest sequence of SecM regulates the SecA-dependent secretion pathway. Previous studies reported many residues of SecM peptide and ribosome exit tunnel are critical for stalling. However, the underlying molecular mechanism is still not clear at the atomic level. Here, we present two cryo-EM structures of the SecM-stalled ribosomes at 3.3-3.7 Å resolution, which reveal two different stalling mechanisms at distinct elongation steps of the translation cycle: one is due to the inactivation of ribosomal peptidyl-transferase center which inhibits peptide bond formation with the incoming prolyl-tRNA; the other is the prolonged residence of the peptidyl-RNA at the hybrid A/P site which inhibits the full-scale tRNA translocation. These results demonstrate an elegant control of translation cycle by regulatory peptides through a continuous, dynamic reshaping of the functional center of the ribosome. |
![]() | ![]() ![]() ![]() |
手法 | EM (単粒子) |
解像度 | 3.32 - 3.73 Å |
構造データ | EMDB-6483, PDB-3jbu: ![]() EMDB-6484: ![]() EMDB-6485: |
化合物 | ![]() ChemComp-CLM: |
由来 |
|
![]() | RIBOSOME / single particle analysis / ribosome stalling |