ジャーナル: J Biol Chem / 年: 2013 タイトル: Large terminase conformational change induced by connector binding in bacteriophage T7. 著者: María I Daudén / Jaime Martín-Benito / Juan C Sánchez-Ferrero / Mar Pulido-Cid / José M Valpuesta / José L Carrascosa / 要旨: During bacteriophage morphogenesis DNA is translocated into a preformed prohead by the complex formed by the portal protein, or connector, plus the terminase, which are located at an especial prohead ...During bacteriophage morphogenesis DNA is translocated into a preformed prohead by the complex formed by the portal protein, or connector, plus the terminase, which are located at an especial prohead vertex. The terminase is a powerful motor that converts ATP hydrolysis into mechanical movement of the DNA. Here, we have determined the structure of the T7 large terminase by electron microscopy. The five terminase subunits assemble in a toroid that encloses a channel wide enough to accommodate dsDNA. The structure of the complete connector-terminase complex is also reported, revealing the coupling between the terminase and the connector forming a continuous channel. The structure of the terminase assembled into the complex showed a different conformation when compared with the isolated terminase pentamer. To understand in molecular terms the terminase morphological change, we generated the terminase atomic model based on the crystallographic structure of its phage T4 counterpart. The docking of the threaded model in both terminase conformations showed that the transition between the two states can be achieved by rigid body subunit rotation in the pentameric assembly. The existence of two terminase conformations and its possible relation to the sequential DNA translocation may shed light into the molecular bases of the packaging mechanism of bacteriophage T7.
ダウンロード / ファイル: emd_2356.map.gz / 形式: CCP4 / 大きさ: 5.2 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Reconstruction of the connector/terminase complex, which presents two different symmetries (c12 and c5 respectively).
ボクセルのサイズ
X=Y=Z: 4.2 Å
密度
表面レベル
登録者による: 0.0248 / ムービー #1: 0.0248
最小 - 最大
-0.02651265 - 0.06766804
平均 (標準偏差)
-0.00067221 (±0.00622457)
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
112
112
112
Spacing
112
112
112
セル
A=B=C: 470.39996 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
4.2
4.2
4.2
M x/y/z
112
112
112
origin x/y/z
0.000
0.000
0.000
length x/y/z
470.400
470.400
470.400
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
-40
NX/NY/NZ
55
55
81
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
112
112
112
D min/max/mean
-0.027
0.068
-0.001
-
添付データ
-
試料の構成要素
-
全体 : Connector/terminase complex of bacteriophage T7
全体
名称: Connector/terminase complex of bacteriophage T7
要素
試料: Connector/terminase complex of bacteriophage T7
タンパク質・ペプチド: connector
タンパク質・ペプチド: large terminase
-
超分子 #1000: Connector/terminase complex of bacteriophage T7
超分子
名称: Connector/terminase complex of bacteriophage T7 / タイプ: sample / ID: 1000 / 集合状態: one homododecamer bound to one homopentamer / Number unique components: 2
分子量
理論値: 1.0 MDa
-
分子 #1: connector
分子
名称: connector / タイプ: protein_or_peptide / ID: 1 / Name.synonym: portal protein, gp8 / 詳細: Each monomer of the connector is a 59 kDa protein. / コピー数: 12 / 集合状態: Dodecamer / 組換発現: Yes
UniProtKB: Portal protein / GO: virion component => GO:0044423
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分子 #2: large terminase
分子
名称: large terminase / タイプ: protein_or_peptide / ID: 2 / Name.synonym: gp19 / 詳細: Each monomer of the terminase is a 67 kDa protein / コピー数: 5 / 集合状態: Pentamer / 組換発現: Yes