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Effect of ε subunit on the rotation of thermophilic Bacillus F 1 ‐ATPase
Author(s) -
Tsumuraya Masato,
Furuike Shou,
Adachi Kengo,
Kinosita Kazuhiko,
Yoshida Masasuke
Publication year - 2009
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2009.02.038
Subject(s) - thermophile , protein subunit , atpase , rotation (mathematics) , chemistry , bacillus (shape) , crystallography , biophysics , biochemistry , biology , enzyme , microbiology and biotechnology , mathematics , geometry , gene
F 1 ‐ATPase is an ATP‐driven motor in which γε rotates in the α 3 β 3 ‐cylinder. It is attenuated by MgADP inhibition and by the ε subunit in an inhibitory form. The non‐inhibitory form of ε subunit of thermophilic Bacillus PS3 F 1 ‐ATPase is stabilized by ATP‐binding with micromolar K d at 25 °C. Here, we show that at [ATP] > 2 μM, ε does not affect rotation of PS3 F 1 ‐ATPase but, at 200 nM ATP, ε prolongs the pause of rotation caused by MgADP inhibition while the frequency of the pause is unchanged. It appears that ε undergoes reversible transition to the inhibitory form at [ATP] below K d .