TABLE 2.

Electron transport chain components of various R. sphaeroides mutants, and their cytochrome contents in membranes^a

Strain	Phenotype	Electron carrier(s)/cyt c oxidase(s)	Cyt c profile					Cyt a	Cyt b	Cyt c	Cyt b/Cyt c ratio
			cp	c1	co	cy	c2
Ga	Ps+ Res+ Nadi+	Cyt c2 + cyt cy/cbb3-Cox + aa3-Cox	+	+	+	+	+	0.8	2.2	3.8	0.57
Gadc2	Ps− Res+ Nadi+	Cyt cy/cbb3-Cox + aa3-Cox	+	+	+	+	−	0.34	1.0	1.3	0.77
Gadcy	Ps+ Res+ Nadi+	Cyt c2/cbb3-Cox + aa3-Cox	+	+	+	−	+	0.37	1.0	1.45	0.68
Gadc2cy	Ps− Res+ Nadi+	None/cbb3-Cox + aa3-Cox	+	+	+	−	−	0.24	1.0	0.95	1.05
MT001	Ps+ Res+ Nadislow	Cyt c2 + cyt cy/aa3-Cox	−	+	−	+	+	0.48	1.15	1.14	1.0
KD02	Ps− Res+ Nadislow	Cyt cy/aa3-Cox	−	+	−	+	−	0.42	0.93	0.7	1.3
KD04	Ps+ Res+ Nadislow	Cyt c2/aa3-Cox	−	+	−	−	+	0.42	0.87	0.69	1.26
JS100	Ps+ Res+ Nadi+	Cyt c2 + cyt cy/cbb3-Cox	+	+	+	+	+	NDb	1.2	1.9	0.63
KD03	Ps+ Res+ Nadi+	Cyt cy/cbb3-Cox	+	+	+	−	+	ND	1.42	1.65	0.86
KD05	Ps− Res+ Nadi+	Cyt cy/cbb3-Cox	+	+	+	+	−	ND	2.2	1.56	0.87
ME127	Ps+ Res+ Nadi−	Cyt c2 + cyt cy/none	−	+	−	+	+	ND	1.28	1.06	1.2
BC17	Ps− Res+ Nadi+	Cyt c2 + cyt cy/cbb3-Cox + aa3-Cox	+	−	+	+	+	0.5	1.05	2.05	0.5

^aCyt a, cyt b, and cyt c values are expressed as nanomoles of heme per milligram of protein, using appropriate extinction coefficients, as described in Materials and Methods. Cyt c profiles are tabulated from the data in Fig. 4. 

^bND, not detected.