ジャーナル: Sci Rep / 年: 2017 タイトル: Pea PSII-LHCII supercomplexes form pairs by making connections across the stromal gap. 著者: Pascal Albanese / Roberto Melero / Benjamin D Engel / Alessandro Grinzato / Paola Berto / Marcello Manfredi / Angelica Chiodoni / Javier Vargas / Carlos Óscar Sánchez Sorzano / Emilio ...著者: Pascal Albanese / Roberto Melero / Benjamin D Engel / Alessandro Grinzato / Paola Berto / Marcello Manfredi / Angelica Chiodoni / Javier Vargas / Carlos Óscar Sánchez Sorzano / Emilio Marengo / Guido Saracco / Giuseppe Zanotti / Jose-Maria Carazo / Cristina Pagliano / 要旨: In higher plant thylakoids, the heterogeneous distribution of photosynthetic protein complexes is a determinant for the formation of grana, stacks of membrane discs that are densely populated with ...In higher plant thylakoids, the heterogeneous distribution of photosynthetic protein complexes is a determinant for the formation of grana, stacks of membrane discs that are densely populated with Photosystem II (PSII) and its light harvesting complex (LHCII). PSII associates with LHCII to form the PSII-LHCII supercomplex, a crucial component for solar energy conversion. Here, we report a biochemical, structural and functional characterization of pairs of PSII-LHCII supercomplexes, which were isolated under physiologically-relevant cation concentrations. Using single-particle cryo-electron microscopy, we determined the three-dimensional structure of paired CSM PSII-LHCII supercomplexes at 14 Å resolution. The two supercomplexes interact on their stromal sides through a specific overlap between apposing LHCII trimers and via physical connections that span the stromal gap, one of which is likely formed by interactions between the N-terminal loops of two Lhcb4 monomeric LHCII subunits. Fast chlorophyll fluorescence induction analysis showed that paired PSII-LHCII supercomplexes are energetically coupled. Molecular dynamics simulations revealed that additional flexible physical connections may form between the apposing LHCII trimers of paired PSII-LHCII supercomplexes in appressed thylakoid membranes. Our findings provide new insights into how interactions between pairs of PSII-LHCII supercomplexes can link adjacent thylakoids to mediate the stacking of grana membranes.
EMPIAR-10198 (タイトル: Paired C2S2M PSII-LHCII supercomplexes from thylakoid membranes of Pisum sativum Data size: 433.1 / Data #1: 2.outputMicrographs [micrographs - single frame])
ダウンロード / ファイル: emd_3825.map.gz / 形式: CCP4 / 大きさ: 244.1 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Three-dimensional cryo-EM density map of paired C2S2M PSII-LHCII supercomplexes from thylakoid membranes of Pisum sativum
ボクセルのサイズ
X=Y=Z: 1.4 Å
密度
表面レベル
登録者による: 0.0003 / ムービー #1: 0.0003
最小 - 最大
-0.0027011025 - 0.022493664
平均 (標準偏差)
0.0000822539 (±0.00074280193)
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
400
400
400
Spacing
400
400
400
セル
A=B=C: 560.0 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
1.4
1.4
1.4
M x/y/z
400
400
400
origin x/y/z
0.000
0.000
0.000
length x/y/z
560.000
560.000
560.000
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
400
400
400
D min/max/mean
-0.003
0.022
0.000
-
添付データ
-
試料の構成要素
-
全体 : paired PSII-LHCII supercomplexes from pea plants
全体
名称: paired PSII-LHCII supercomplexes from pea plants
要素
複合体: paired PSII-LHCII supercomplexes from pea plants
-
超分子 #1: paired PSII-LHCII supercomplexes from pea plants
超分子
名称: paired PSII-LHCII supercomplexes from pea plants / タイプ: complex / ID: 1 / 親要素: 0 詳細: paired PSII-LHCII supercomplexes connected across the stromal gap