Overall Structural Features of the F-, V-, and A-ATPases

Overall Structural Features of the F-, V-, and A-ATPases A. Structure of the F-ATPase 

The nucleotide occupancy of the catalytic sites observed in the first crystal structure was exactly what Paul Boyer had predicted earlier in his binding-change model of cooperative catalysis (Boyer, 1993). Consequently, this first high-resolution structure of the Fj-ATPase immediately initiated a number of studies that ultimately led to the elucidation of the F -. TPase s rotational mechanism of cooperative catalysis. At the time, the F - ATPase structure represented the largest asymmetric structure solved to atomic resolution by x-ray crystallography, and this accomplishment, together with the visionary prediction of rotary catalysis, was subsequently awarded the 1997 Nobel prize in chemistry (to John Walker for the structure and Paul Boyer for the catalytic mechanism). However, whether the first (and many subsequent) structure (s) represented physiologically 

At the time of this writing, there is no high-resolution structural model available for the intact membrane domain of the F-ATPase. The atomic resolution structure of the monomeric ( -subunit dissolved in organic solvent has been determined by nuclear magnetic resonance (NMR) spectroscopy at neutral and acidic pH (Girvin et al., 1998 Rastogi and Girvin, 

What is known is that the ( -subunits from different species are able to form rings of between 10 and 14 proteolipids. For example, the x-ray crystal structure of the yeast F-ATPase (Stock et at, 1999) shows that there are 10 e-subunits, whereas the chloroplast enzyme has 14 (Seelert et at, 

Subunit a has been modeled as a transmembrane protein containing either five (Vik et al., 2000 Yamada et al., 1996) or six (Jager et al, 1998) transmembrane a-helices. The secondary structure of E. colt subunit a dissolved in organic solvent has been determined by NMR spectroscopy (Dmitriev et al, 2004a,b). 

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