1.
FEBS Lett
; 352(2): 243-6, 1994 Sep 26.
Article
in English
| MEDLINE
| ID: mdl-7925981
ABSTRACT
A beta subunit mutation, beta Val-153-->Cys, in the glycine-rich sequence (phosphate-binding loop) of Escherichia coli F1 was constructed. Like vacuolar-type ATPase, the mutant enzyme was inhibited by N-ethylmaleimide (NEM) and labeled with [14C]NEM. The inhibition and labeling were prevented by ATP. m-Maleimidobenzoyl-N-hydroxysuccinimide (MBS) (3 microM) almost completely inhibited the mutant enzyme, and cross-linked one pair of alpha and beta subunits. These results suggest that the interaction of the domain near beta Val-153 with the alpha subunit is essential for catalytic cooperativity of the enzyme and that beta Val-153 is within 10 A of the alpha subunit.