TABLE 2.

Oxidative phosphorylation in vivo and ATP synthesis activities in vitro Oxidative phosphorylation in vivo and ATP synthesis activities of membrane preparations of deletion mutants and controls were measured as described under “Experimental Procedures.” The positive control was strain pTR19-ASDS/DK8, which expresses Bacillus PS3 ATP synthase in E. coli; this strain served as background for the deletions. The negative control was strain pUC118/DK8, which expresses neither PS3 ATP synthase nor the endogenous E. coli enzyme. The amount of F₁F₀ in the membrane preparations was measured by quantitative immunoblot analysis as described under “Experimental Procedures.” Turnover rates were calculated using a molecular mass of 531 kDa for the holoenzyme, taking into account the differing amounts of ATP synthase in the individual membrane preparations. ND, no activity detectable beyond background.

Strain/mutation	Growth yields in limiting glucose	Amount of F1F0 on membranes	NADH-driven ATP synthesis activity	Turnover rate (kcat)
	% wild type	% total protein	milliunits/mg	s–1
Wild type	100	20	71	3.2
pUC118/DK8 (unc–)	61	0	—a
Δ380LQDI383	69	20	42	1.9
Δ384IAIL387	47	10	33	3.0
Δ388GMDE391	73	15	51	3.1
Δ392LSD394	80	20	48	2.2
Δ395EDKL398	58	2.0	ND
Δ399VVHR402	61	2.6	ND
Δ381QDIIAIL387	45	2.4	8	3.0

^aStrain pUC118/DK8 showed a small amount of ATP production, probably due to adenylate kinase activity of the membranes (52). All given values are corrected for this activity