EIPOD fellowship under Marie Sklodowska-Curie Actions COFUND
847543
ドイツ
引用
ジャーナル: Nat Commun / 年: 2024 タイトル: A subgroup of light-driven sodium pumps with an additional Schiff base counterion. 著者: E Podoliak / G H U Lamm / E Marin / A V Schellbach / D A Fedotov / A Stetsenko / M Asido / N Maliar / G Bourenkov / T Balandin / C Baeken / R Astashkin / T R Schneider / A Bateman / J ...著者: E Podoliak / G H U Lamm / E Marin / A V Schellbach / D A Fedotov / A Stetsenko / M Asido / N Maliar / G Bourenkov / T Balandin / C Baeken / R Astashkin / T R Schneider / A Bateman / J Wachtveitl / I Schapiro / V Busskamp / A Guskov / V Gordeliy / A Alekseev / K Kovalev / 要旨: Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region ...Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region essential for sodium transport. Here we identify a subgroup of the NDQ rhodopsins bearing an additional glutamic acid residue in the close vicinity to the retinal Schiff base. We thoroughly characterize a member of this subgroup, namely the protein ErNaR from Erythrobacter sp. HL-111 and show that the additional glutamic acid results in almost complete loss of pH sensitivity for sodium-pumping activity, which is in contrast to previously studied NaRs. ErNaR is capable of transporting sodium efficiently even at acidic pH levels. X-ray crystallography and single particle cryo-electron microscopy reveal that the additional glutamic acid residue mediates the connection between the other two Schiff base counterions and strongly interacts with the aspartic acid of the characteristic NDQ motif. Hence, it reduces its pKa. Our findings shed light on a subgroup of NaRs and might serve as a basis for their rational optimization for optogenetics.
プロトコル: SINGLE WAVELENGTH / 単色(M)・ラウエ(L): M / 散乱光タイプ: x-ray
放射波長
波長: 0.976 Å / 相対比: 1
反射
解像度: 1.707→46.23 Å / Num. obs: 26414 / % possible obs: 94.66 % / 冗長度: 37.6 % / CC1/2: 0.9991 / Rpim(I) all: 0.038 / Net I/σ(I): 13.769
反射 シェル
解像度: 1.707→1.875 Å / Mean I/σ(I) obs: 1.59 / Num. unique obs: 1321 / CC1/2: 0.7444 / Rpim(I) all: 0.518
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解析
ソフトウェア
名称
バージョン
分類
REFMAC
5.8.0267
精密化
MOLREP
位相決定
XDS
データ削減
STARANISO
データスケーリング
精密化
構造決定の手法: 分子置換 / 解像度: 1.71→20 Å / Cor.coef. Fo:Fc: 0.962 / Cor.coef. Fo:Fc free: 0.948 / SU B: 2.793 / SU ML: 0.087 / 交差検証法: THROUGHOUT / ESU R: 0.144 / ESU R Free: 0.133 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
Rfactor
反射数
%反射
Selection details
Rfree
0.21819
1304
4.9 %
RANDOM
Rwork
0.18271
-
-
-
obs
0.18443
25066
75.49 %
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溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK