1: FEBS Lett  2000 Mar 31;470(3):244-8 

Observations of rotation within the F(o)F(1)-ATP synthase: deciding between
rotation of the F(o)c subunit ring and artifact.

Tsunoda SP, Aggeler R, Noji H, Kinosita K Jr, Yoshida M, Capaldi RA.

Research Laboratory of Resources Utilization, Tokyo Institute of Technology,
4259 Nagatsuta, Yokohama, Japan.

F(o)F(1)-ATP synthase mediates coupling of proton flow in F(o) and ATP
synthesis/hydrolysis in F(1) through rotation of central rotor subunits. A ring
structure of F(o)c subunits is widely believed to be a part of the rotor. Using
an attached actin filament as a probe, we have observed the rotation of the
F(o)c subunit ring in detergent-solubilized F(o)F(1)-ATP synthase purified from
Escherichia coli. Similar studies have been performed and reported recently
[Sambongi et al. (1999) Science 286, 1722-1724]. However, in our hands this
rotation has been observed only for the preparations which show poor sensitivity
to dicyclohexylcarbodiimde, an F(o) inhibitor. We have found that detergents
which adequately disperse the enzyme for the rotation assay also tend to
transform F(o)F(1)-ATP synthase into an F(o) inhibitor-insensitive state in
which F(1) can hydrolyze ATP regardless of the state of the F(o). Our results
raise the important issue of whether rotation of the F(o)c ring in isolated
F(o)F(1)-ATP synthase can be demonstrated unequivocally with the approach
adopted here and also used by Sambongi et al.

PMID: 10745076 [PubMed - indexed for MEDLINE]