ジャーナル: EMBO J / 年: 2012 タイトル: Structural insights into initial and intermediate steps of the ribosome-recycling process. 著者: Takeshi Yokoyama / Tanvir R Shaikh / Nobuhiro Iwakura / Hideko Kaji / Akira Kaji / Rajendra K Agrawal / 要旨: The ribosome-recycling factor (RRF) and elongation factor-G (EF-G) disassemble the 70S post-termination complex (PoTC) into mRNA, tRNA, and two ribosomal subunits. We have determined cryo-electron ...The ribosome-recycling factor (RRF) and elongation factor-G (EF-G) disassemble the 70S post-termination complex (PoTC) into mRNA, tRNA, and two ribosomal subunits. We have determined cryo-electron microscopic structures of the PoTC·RRF complex, with and without EF-G. We find that domain II of RRF initially interacts with universally conserved residues of the 23S rRNA helices 43 and 95, and protein L11 within the 50S ribosomal subunit. Upon EF-G binding, both RRF and tRNA are driven towards the tRNA-exit (E) site, with a large rotational movement of domain II of RRF towards the 30S ribosomal subunit. During this intermediate step of the recycling process, domain II of RRF and domain IV of EF-G adopt hitherto unknown conformations. Furthermore, binding of EF-G to the PoTC·RRF complex reverts the ribosome from ratcheted to unratcheted state. These results suggest that (i) the ribosomal intersubunit reorganizations upon RRF binding and subsequent EF-G binding could be instrumental in destabilizing the PoTC and (ii) the modes of action of EF-G during tRNA translocation and ribosome-recycling steps are markedly different.
ダウンロード / ファイル: emd_1916.map.gz / 形式: CCP4 / 大きさ: 8.2 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
T.thermophilus Ribosome Recycling Factor, ttRRF This is the excised density corresponding to ttRRF from the parent map EMD-1916
ボクセルのサイズ
X=Y=Z: 2.78 Å
密度
表面レベル
登録者による: 74.400000000000006 / ムービー #1: 74.4
最小 - 最大
-53.603660580000003 - 766.382324219999987
平均 (標準偏差)
0.17248684 (±7.56605721)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
0
0
0
サイズ
130
130
130
Spacing
130
130
130
セル
A=B=C: 361.4 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
2.78
2.78
2.78
M x/y/z
130
130
130
origin x/y/z
0.000
0.000
0.000
length x/y/z
361.400
361.400
361.400
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
-56
-56
-55
NX/NY/NZ
112
112
112
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
130
130
130
D min/max/mean
-53.604
766.382
0.172
-
添付データ
-
試料の構成要素
-
全体 : T. thermophilus Ribosome Recycling Factor
全体
名称: T. thermophilus Ribosome Recycling Factor
要素
試料: T. thermophilus Ribosome Recycling Factor
タンパク質・ペプチド: Ribosome Recycling Factor
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超分子 #1000: T. thermophilus Ribosome Recycling Factor
超分子
名称: T. thermophilus Ribosome Recycling Factor / タイプ: sample / ID: 1000 / 集合状態: monomer / Number unique components: 1
分子量
理論値: 21 KDa
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分子 #1: Ribosome Recycling Factor
分子
名称: Ribosome Recycling Factor / タイプ: protein_or_peptide / ID: 1 / Name.synonym: ttRRF 詳細: This is the excised density coresponding to ttRRF from the parent map EMD-1916. T.thermophilus RRF, encoded on pGEM-T plasmid, was overexpressed in the E.coli strain JM109. 組換発現: Yes