alpha3beta3gamma complex of F1-ATPase from thermophilic Bacillus PS3 can maintain steady-state ATP hydrolysis activity depending on the number of non-catalytic sites.
Homogeneous preparations of alpha(3)beta(3)gamma complexes with one, two or three non-competent non-catalytic site(s) were performed as described [Amano, Hisabori, Muneyuki, and Yoshida (1996) J. Biol. Chem. 271, 18128-18133] and their properties were compared with those of the wild-type complex. The ATPase activity of the complex with three non-competent non-catalytic sites decayed rapidly to an inactivated state, as reported previously [Matsui, Muneyuki, Honda, Allison, Dou, and Yoshida (1997) J. Biol. Chem. 272, 8215-8221]. In contrast, the complex with one or two non-competent non-catalytic sites displayed a substantial steady-state phase activity depending on the number of non-competent non-catalytic sites in the complex. This result indicates that one competent non-catalytic site can maintain the continuous catalytic turnover of the enzyme and can potentially relieve all three catalytic sites from inhibition by MgADP(-). Furthermore, the results suggest that the interaction between three non-catalytic sites might not be as strong as that between catalytic sites, which are all strictly required for a continuous catalytic turnover.
Amano
T
T
Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503, Japan.
Matsui
T
T
Muneyuki
E
E
Noji
H
H
Hara
K
K
Yoshida
M
M
Hisabori
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology*; D001483:Base Sequence; D020134:Catalytic Domain; D017931:DNA Primers; D004123:Dimethylamines / Q000494:pharmacology; D020536:Enzyme Activators / Q000494:pharmacology; D006868:Hydrolysis; D016297:Mutagenesis, Site-Directed; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*
D017931:DNA Primers; D004123:Dimethylamines; D020536:Enzyme Activators; C014518:dodecyldimethylamine oxide; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases