ジャーナル: J Mol Biol / 年: 2013 タイトル: Location of the dsRNA-dependent polymerase, VP1, in rotavirus particles. 著者: Leandro F Estrozi / Ethan C Settembre / Gaël Goret / Brian McClain / Xing Zhang / James Z Chen / Nikolaus Grigorieff / Stephen C Harrison / 要旨: Double-stranded RNA (dsRNA) viruses transcribe and replicate RNA within an assembled, inner capsid particle; only plus-sense mRNA emerges into the intracellular milieu. During infectious entry of a ...Double-stranded RNA (dsRNA) viruses transcribe and replicate RNA within an assembled, inner capsid particle; only plus-sense mRNA emerges into the intracellular milieu. During infectious entry of a rotavirus particle, the outer layer of its three-layer structure dissociates, delivering the inner double-layered particle (DLP) into the cytosol. DLP structures determined by X-ray crystallography and electron cryomicroscopy (cryoEM) show that the RNA coils uniformly into the particle interior, avoiding a "fivefold hub" of more structured density projecting inward from the VP2 shell of the DLP along each of the twelve 5-fold axes. Analysis of the X-ray crystallographic electron density map suggested that principal contributors to the hub are the N-terminal arms of VP2, but reexamination of the cryoEM map has shown that many features come from a molecule of VP1, randomly occupying five equivalent and partly overlapping positions. We confirm here that the electron density in the X-ray map leads to the same conclusion, and we describe the functional implications of the orientation and position of the polymerase. The exit channel for the nascent transcript directs the nascent transcript toward an opening along the 5-fold axis. The template strand enters from within the particle, and the dsRNA product of the initial replication step exits in a direction tangential to the inner surface of the VP2 shell, allowing it to coil optimally within the DLP. The polymerases of reoviruses appear to have similar positions and functional orientations.
A: 237.5 Å / B: 473.30356 Å / C: 237.5 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
1.6964285714286
1.6964301075269
1.6964285714286
M x/y/z
140
279
140
origin x/y/z
0.000
0.000
0.000
length x/y/z
237.500
473.304
237.500
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
0
NX/NY/NZ
128
128
168
MAP C/R/S
1
2
3
start NC/NR/NS
0
-139
-139
NC/NR/NS
140
279
140
D min/max/mean
-0.004
0.008
0.000
-
添付データ
-
試料の構成要素
-
全体 : Rotavirus DLP+VP1
全体
名称: Rotavirus DLP+VP1
要素
試料: Rotavirus DLP+VP1
タンパク質・ペプチド: Rotavirus polymerase (VP1)
タンパク質・ペプチド: VP1
タンパク質・ペプチド: VP2
タンパク質・ペプチド: VP3
RNA: dsRNA
-
超分子 #1000: Rotavirus DLP+VP1
超分子
名称: Rotavirus DLP+VP1 / タイプ: sample / ID: 1000 集合状態: 780 molecules of VP6 form a DLP particle with 12 molecules of VP1, 120 molecules of VP2, 12 molecules of VP3 and 11 dsRNA molecules Number unique components: 5
-
分子 #1: Rotavirus polymerase (VP1)
分子
名称: Rotavirus polymerase (VP1) / タイプ: protein_or_peptide / ID: 1 / Name.synonym: VP1 詳細: The icosahedral 3D reconstruction of rotavirus DLP shows extra-density near the 5-fold axis corresponding to one copy of VP1 attached to the DLP inner surface. コピー数: 11 / 組換発現: No
名称: dsRNA / タイプ: rna / ID: 5 / Name.synonym: dsRNA / 分類: OTHER / Structure: OTHER / Synthetic?: No
由来(天然)
生物種: Bovine rotavirus (ウイルス) / 別称: Rotavirus
-
実験情報
-
構造解析
手法
クライオ電子顕微鏡法
解析
単粒子再構成法
試料の集合状態
particle
-
試料調製
濃度
5 mg/mL
緩衝液
pH: 7.4
グリッド
詳細: Lacy carbon and C-flat
凍結
凍結剤: ETHANE / チャンバー内湿度: 30 % / 装置: HOMEMADE PLUNGER 詳細: Vitrification instrument: Home-made. Vitrification carried out in air at room temperature 手法: Blot for 3 seconds before plunging
-
電子顕微鏡法
顕微鏡
FEI TECNAI F30
温度
平均: 90 K
アライメント法
Legacy - 非点収差: Objective lens astigmatism was corrected