NMR solution structure of subunit F of the methanogenic A1AO adenosine triphosphate synthase and its interaction with the nucleotide-binding subunit B.
NMR solution structure of subunit F of the methanogenic A1AO adenosine triphosphate synthase and its interaction with the nucleotide-binding subunit B.
复制标题
产甲烷 A1AO 三磷酸腺苷合酶 F 亚基的 NMR 溶液结构及其与核苷酸结合亚基 B 的相互作用。
作者：
S. Gayen;S. Vivekanandan;G. Biuković;G. Grüber;H. Yoon
来自古细菌的A1AO三磷酸腺苷（ATP）合成酶利用跨膜区（AO）产生的离子梯度在A1区A3B3结构域合成ATP。两个活性结构域之间的能量耦合通过所谓的茎部发生，其中12 kDa亚基F确实属于茎部。在这里，我们提出了Methanosarcina mazei Gö1 A1AO ATP合成酶的F亚基的溶液结构。亚基F具有明显的双域结构，n端有78个残基，79-101个残基形成柔性的c端部分。有序的n端结构域由一个四股平行的β -片结构和三个交替放置的α -螺旋组成。这两个领域是松散地联系在一起的，相对于彼此具有更大的灵活性。动力学研究进一步证实了c端结构域的柔韧性。此外，利用天然亚基B （Trp430）的荧光信号定量测定突变亚基F与核苷酸结合亚基B的亲和力，突变亚基F在极c末端取代了Tyr和Ile。最后给出了配合物内F亚基的排列。
The A1AO adenosine triphosphate (ATP) synthase from archaea uses the ion gradients generated across the membrane sector (AO) to synthesize ATP in the A3B3 domain of the A1 sector. The energy coupling between the two active domains occurs via the so-called stalk part(s), to which the 12 kDa subunit F does belong. Here, we present the solution structure of the F subunit of the A1AO ATP synthase from Methanosarcina mazei Gö1. Subunit F exhibits a distinct two-domain structure, with the N-terminal having 78 residues and residues 79-101 forming the flexible C-terminal part. The well-ordered N-terminal domain is composed of a four-stranded parallel beta-sheet structure and three alpha-helices placed alternately. The two domains are loosely associated with more flexibility relative to each other. The flexibility of the C-terminal domain is further confirmed by dynamics studies. In addition, the affinity of binding of mutant subunit F, with a substitution of Trp100 against Tyr and Ile at the very C-terminal end, to the nucleotide-binding subunit B was determined quantitatively using the fluorescence signals of natural subunit B (Trp430). Finally, the arrangement of subunit F within the complex is presented.