ジャーナル: Phys Biol / 年: 2010 タイトル: Cryo-reconstructions of P22 polyheads suggest that phage assembly is nucleated by trimeric interactions among coat proteins. 著者: Kristin N Parent / Robert S Sinkovits / Margaret M Suhanovsky / Carolyn M Teschke / Edward H Egelman / Timothy S Baker / 要旨: Bacteriophage P22 forms an isometric capsid during normal assembly, yet when the coat protein (CP) is altered at a single site, helical structures (polyheads) also form. The structures of three ...Bacteriophage P22 forms an isometric capsid during normal assembly, yet when the coat protein (CP) is altered at a single site, helical structures (polyheads) also form. The structures of three distinct polyheads obtained from F170L and F170A variants were determined by cryo-reconstruction methods. An understanding of the structures of aberrant assemblies such as polyheads helps to explain how amino acid substitutions affect the CP, and these results can now be put into the context of CP pseudo-atomic models. F170L CP forms two types of polyhead and each has the CP organized as hexons (oligomers of six CPs). These hexons have a skewed structure similar to that in procapsids (precursor capsids formed prior to dsDNA packaging), yet their organization differs completely in polyheads and procapsids. F170A CP forms only one type of polyhead, and though this has hexons organized similarly to hexons in F170L polyheads, the hexons are isometric structures like those found in mature virions. The hexon organization in all three polyheads suggests that nucleation of procapsid assembly occurs via a trimer of CP monomers, and this drives formation of a T = 7, isometric particle. These variants also form procapsids, but they mature quite differently: F170A expands spontaneously at room temperature, whereas F170L requires more energy. The P22 CP structure along with scaffolding protein interactions appear to dictate curvature and geometry in assembled structures and residue 170 significantly influences both assembly and maturation.
ダウンロード / ファイル: emd_1747.map.gz / 形式: CCP4 / 大きさ: 317.3 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
This is a helical reconstruction of P22 polyheads from F170A coat protein with C3 symmetry
ボクセルのサイズ
X=Y=Z: 1.62 Å
密度
表面レベル
登録者による: 0.3 / ムービー #1: 0.3
最小 - 最大
-1.00258 - 1.3638
平均 (標準偏差)
0.0121384 (±0.242558)
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
440
440
440
Spacing
440
440
440
セル
A=B=C: 712.8 Å α=β=γ: 90 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
1.62
1.62
1.62
M x/y/z
440
440
440
origin x/y/z
-0.000
-0.000
-0.000
length x/y/z
712.800
712.800
712.800
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
-100
-100
-100
NX/NY/NZ
200
200
200
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
440
440
440
D min/max/mean
-1.003
1.364
0.012
-
添付データ
-
試料の構成要素
-
全体 : F170A coat protein in C3 helical lattice
全体
名称: F170A coat protein in C3 helical lattice
要素
試料: F170A coat protein in C3 helical lattice
ウイルス: Enterobacteria phage P22 (ファージ)
-
超分子 #1000: F170A coat protein in C3 helical lattice
超分子
名称: F170A coat protein in C3 helical lattice / タイプ: sample / ID: 1000 詳細: This sample was purified from phage-infected cells. The asymmetric unit is a hexon. Number unique components: 1
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超分子 #1: Enterobacteria phage P22
超分子
名称: Enterobacteria phage P22 / タイプ: virus / ID: 1 / Name.synonym: P22 coat protein / NCBI-ID: 10754 / 生物種: Enterobacteria phage P22 / データベース: NCBI / ウイルスタイプ: VIRION / ウイルス・単離状態: STRAIN / ウイルス・エンベロープ: No / ウイルス・中空状態: Yes / Syn species name: P22 coat protein