Structural characterization of NDH-1 complexes of Thermosynechococcus elongatus by single particle electron microscopy
Structural characterization of NDH-1 complexes of Thermosynechococcus elongatus by single particle electron microscopy
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DOI：
10.1016/j.bbabio.2006.05.042
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发表时间：
2006-11-01
影响因子：
4.3
通讯作者：
Boekema, Egbert J.
中科院分区：
文献类型：
--
作者：
Arteni, Ana A.;Zhang, Pengpeng;Boekema, Egbert J.
通过在不同CO2条件下培养细长热聚球藻BP-1的野生型和特异性ndh His标签突变体，研究了蓝藻多功能NAD（P）H脱氢酶1型（NDH-1）复合物的结构，并对其纯化的膜蛋白复合物进行了电镜分析。单颗粒平均显示完整的NDH-1复合物（NDH-1 L）是L形的，具有相对较短的亲水臂。观察到两个较小的复合物，仅在膜包埋的ann的尖端处不同。最小的一个被认为与NDH-1 M相似，缺少NdhD 1和NdhF 1亚基。另一个片段命名为NDH-1 I，介于NDH-1 L和NDH-1 M之间，仅缺乏与NdhF 1亚基大小相容的质量。这两个较小的复合物在低和高CO2生长条件下观察到，但在后者的条件下更丰富。蓝藻NDH-1的EM表征进一步显示了少量的NDH-1复合物与额外的质量。一种颗粒具有更长的外环，类似于大肠杆菌中的NADH：泛醌氧化还原酶（复合物1）。大肠杆菌和其他微生物。这表明细长热聚球藻必须具有与E. coli NuoE、-F和-G亚基。另一种低丰度类型的颗粒（NDH-1U）在膜包埋臂的尖端具有第二个不稳定的亲水臂。(c)2006 Elsevier B. V.保留所有权利。
The structure of the multifunctional NAD(P)H dehydrogenase type 1 (NDH-1) complexes from cyanobacteria was investigated by growing the wild type and specific ndh His-tag mutants of Thermosynechococcus elongatus BP-1 under different CO2 conditions, followed by an electron microscopy (EM) analysis of their purified membrane protein complexes. Single particle averaging showed that the complete NDH-1 complex (NDH-1L) is L-shaped, with a relatively short hydrophilic arm. Two smaller complexes were observed, differing only at the tip of the membrane-embedded ann. The smallest one is considered to be similar to NDH-1M, lacking the NdhD1 and NdhF1 subunits. The other fragment, named NDH-1I, is intermediate between NDH-1L and NDH-1M and only lacks a mass compatible with the size of the NdhF1 subunit. Both smaller complexes were observed under low- and high-CO2 growth conditions, but were much more abundant under the latter conditions. EM characterization of cyanobacterial NDH-1 further showed small numbers of NDH-1 complexes with additional masses. One type of particle has a much longer peripheral ann, similar to the one of NADH: ubiquinone oxidoreductase (complex 1) in E. coli and other organisms. This indicates that Thermosynechococcus elongatus must have protein(s) which are structurally homologous to the E. coli NuoE, -F, and -G subunits. Another low-abundance type of particle (NDH-1U) has a second labile hydrophilic arm at the tip of the membrane-embedded arm. This U-shaped particle has not been observed before by EM in a NDH-1 preparation. (c) 2006 Elsevier B.V. All rights reserved.