Table 1.

Properties of E. coli Wild-Type and Variant NadA Proteins^a

Sample	Iron per polypeptide	Sulfide per polypeptide	Ratioc	Turnover number (U)b
				As Isolated		Reconstituted
				NadB	OAA/AS	NadB	OAA/AS
WT	3.0 ± 0.1	2.3 ± 0.1	4.5	0.30	2.2	1.8	4.1
C64S	1.4 ± 0.1	0.73 ± 0.2	5.5	0.15	0.52	1.4	1.9
C113A	0.84 ± 0.1	0.9 ± 0.1	8.2	ND	ND	ND	ND
C113S	1.3 ± 0.4	0.4 ± 0.1	9.8	ND	ND	ND	ND
C119S	1.0 ± 0.4	0.6 ± 0.1	8.7	0.01	0.01	0.20	0.28
C128S	2.7 ± 0.1	1.1 ± 0.1	3.6	0.30	0.26	0.97	0.66
C195S	1.5 ± 0.1	1.5 ± 0.1	5.5	0.22	0.69	2.8	3.2
C200A	1.5 ± 0.3	1.2 ± 0.1	7.1	ND	ND	ND	ND
C200S	1.0 ± 0.3	0.5 ± 0.1	8.6	ND	ND	ND	ND
C291S	0.8 ± 0.1	0.5 ± 0.1	10.2	0.09	0.33	1.6	3.3
C294S	2.1 ± 0.1	1.8 ± 0.2	4.6	1.1	2.0	4.2	3.0
C297A	0.3 ± 0.1	0.5 ± 0.1	15.3	ND	ND	ND	ND
C297S	0.3 ± 0.2	0.1 ± 0.1	19.4	ND	ND	ND	ND

^aND, activity not detected. Reported errors reflect one standard deviation

^bUnit (U) defined as μM quinolinic acid per μM NadA, per min

^cDefined as A_{280 nm}/A_{400 nm}