Molecular architecture of the undecameric rotor of a bacterial Na+-ATP synthase.
Molecular architecture of the undecameric rotor of a bacterial Na+-ATP synthase.
复制标题
细菌 Na -ATP 合酶十一聚体转子的分子结构。
DOI：
10.1016/s0022-2836(02)00597-1
复制
发表时间：
2002
影响因子：
5.6
通讯作者：
P. Dimroth
中科院分区：
文献类型：
--
作者：
J. Vonck;Tassilo Krug von Nidda;T. Meier;U. Matthey;D. Mills;W. Kühlbrandt;P. Dimroth
酒石伊氏杆菌钠离子转运型F1F0ATP合成酶含有一个非常稳定的转子环，由11个c亚基组成。分离了转子环，进行了二维结晶，并进行了电子冷冻显微镜分析。在这里，我们提出了c-亚单位环的α-Carbon模型。氨基酸残基的每个单体c亚基折叠成一个螺旋发夹，由两个跨膜螺旋和一个细胞质环组成。11个N-末端螺旋紧密地间隔在围绕∼17？(1.7 nm)腔的内环内。紧密的螺旋堆积没有为侧链留下空间，并且由内部N-末端螺旋中四个甘氨酸残基的高度保守基序所解释。每个内部螺旋通过一个清晰可见的环连接到外部C-末端螺旋。外螺旋在膜中央离子结合位点残基Glu65的位置附近有一个扭结，在C末端附近有另一个扭结。来自外环的两个螺旋和来自内环的一个螺旋形成了膜中央的离子结合部位和从结合部位到细胞质表面的潜在通道。与其他生物相比，三种可能的亚基间离子桥可能解释了I.taricus c环显着的温度稳定性。
The sodium ion-translocating F1F0ATP synthase from the bacterium Ilyobacter tartaricus contains a remarkably stable rotor ring composed of 11 c subunits. The rotor ring was isolated, crystallised in two dimensions and analysed by electron cryo-microscopy. Here, we present an α-carbon model of the c-subunit ring. Each monomeric c subunit of 89 amino acid residues folds into a helical hairpin consisting of two membrane-spanning helices and a cytoplasmic loop. The 11 N-terminal helices are closely spaced within an inner ring surrounding a cavity of ∼17Å (1.7nm). The tight helix packing leaves no space for side-chains and is accounted for by a highly conserved motif of four glycine residues in the inner, N-terminal helix. Each inner helix is connected by a clearly visible loop to an outer C-terminal helix. The outer helix has a kink near the position of the ion-binding site residue Glu65 in the centre of the membrane and another kink near the C terminus. Two helices from the outer ring and one from the inner ring form the ion-binding site in the middle of the membrane and a potential access channel from the binding site to the cytoplasmic surface. Three possible inter-subunit ion-bridges are likely to account for the remarkable temperature stability of I.tartaricus c-rings compared to those of other organisms.
登录
查看更多内容
影响因子：
5.6
作者：
Luecke, H;Schobert, B;Lanyi, JK
通讯作者：
Lanyi, JK
DOI：
10.1073/pnas.96.14.7785
发表时间：
1999-07-06
影响因子：
11.1
作者：
Dmitriev, OY;Jones, PC;Fillingame, RH
通讯作者：
Fillingame, RH
影响因子：
2.9
作者：
Girvin, ME;Rastogi, VK;Fillingame, RH
通讯作者：
Fillingame, RH
影响因子：
5.6
作者：
HENDERSON, R;BALDWIN, JM;DOWNING, KH
通讯作者：
DOWNING, KH