bi701102n_si_001.pdf (375.97 kB)
NMR Solution Structure of Subunit F of the Methanogenic A1AO Adenosine Triphosphate Synthase and Its Interaction with the Nucleotide-Binding Subunit B†,‡
journal contribution
posted on 2007-10-23, 00:00 authored by Shovanlal Gayen, Subramanian Vivekanandan, Goran Biuković, Gerhard Grüber, Ho Sup YoonThe 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 β-sheet structure and three α-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.