ジャーナル: J Am Chem Soc / 年: 2020 タイトル: Folding of an Intrinsically Disordered Iron-Binding Peptide in Response to Sedimentation Revealed by Cryo-EM. 著者: Geula Davidov / Gili Abelya / Ran Zalk / Benjamin Izbicki / Sharon Shaibi / Lior Spektor / Dayana Shagidov / Esther G Meyron-Holtz / Raz Zarivach / Gabriel A Frank / 要旨: Biomineralization is mediated by specialized proteins that guide and control mineral sedimentation. In many cases, the active regions of these biomineralization proteins are intrinsically disordered. ...Biomineralization is mediated by specialized proteins that guide and control mineral sedimentation. In many cases, the active regions of these biomineralization proteins are intrinsically disordered. High-resolution structures of these proteins while they interact with minerals are essential for understanding biomineralization processes and the function of intrinsically disordered proteins (IDPs). Here we used the cavity of ferritin as a nanoreactor where the interaction between M6A, an intrinsically disordered iron-binding domain, and an iron oxide particle was visualized at high resolution by cryo-EM. Taking advantage of the differences in the electron-dose sensitivity of the protein and the iron oxide particles, we developed a method to determine the irregular shape of the particles found in our density maps. We found that the folding of M6A correlates with the detection of mineral particles in its vicinity. M6A interacts with the iron oxide particles through its C-terminal side, resulting in the stabilization of a helix at its N-terminal side. The stabilization of the helix at a region that is not in direct contact with the iron oxide particle demonstrates the ability of IDPs to respond to signals from their surroundings by conformational changes. These findings provide the first glimpse toward the long-suspected mechanism for biomineralization protein control over mineral microstructure, where unstructured regions of these proteins become more ordered in response to their interaction with the nascent mineral particles.
ダウンロード / ファイル: emd_11265.map.gz / 形式: CCP4 / 大きさ: 64 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Acetate treated L-Ferritin-M6A fusion protein.
ボクセルのサイズ
X=Y=Z: 1.1 Å
密度
表面レベル
登録者による: 0.03 / ムービー #1: 0.03
最小 - 最大
-0.071648836 - 0.15990445
平均 (標準偏差)
0.00027757054 (±0.0072521134)
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
256
256
256
Spacing
256
256
256
セル
A=B=C: 281.6 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
1.1
1.1
1.1
M x/y/z
256
256
256
origin x/y/z
0.000
0.000
0.000
length x/y/z
281.600
281.600
281.600
α/β/γ
90.000
90.000
90.000
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
256
256
256
D min/max/mean
-0.072
0.160
0.000
-
添付データ
-
試料の構成要素
-
全体 : Iron-loaded L-Ferritin-M6A
全体
名称: Iron-loaded L-Ferritin-M6A
要素
複合体: Iron-loaded L-Ferritin-M6A
タンパク質・ペプチド: Ferritinフェリチン
-
超分子 #1: Iron-loaded L-Ferritin-M6A
超分子
名称: Iron-loaded L-Ferritin-M6A / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: Nano cage L_ferritin_M6A at 0.1 mg per mL concentration after sodium acetate treatment with 0.044 mM FeCl2, Iron loaded