Table 1.

Kinetic parameters of ALAS enzymes for ALA formation^a.

ALASs	${\mathit{K}}_{\mathit{d}}^{\mathit{Gly},\mathit{app}}$	${\mathit{K}}_{\mathit{s}}^{\mathit{Gly}}$	${\mathit{K}}_{\mathit{m}}^{\mathit{Gly}}$	${\mathit{K}}_{\mathit{m}}^{\mathit{SCoA}}$	k cat
	mM	mM	mM	µM	s−1
C. crescentus
Wild type	10.56 ± 1.35	12.45 ± 1.74	3.31 ± 0.45	2.42 ± 0.32	1.73 ± 0.09
H340A	11.53 ± 1.17	15.02 ± 2.73	3.52 ± 0.67	2.40 ± 0.46	1.61 ± 0.12
C398A	13.57 ± 3.10	15.63 ± 2.19	3.40 ± 0.47	2.55 ± 0.32	1.69 ± 0.07
H340A/C398A	6.46 ± 1.50	12.85 ± 2.27	3.57 ± 0.58	2.58 ± 0.39	1.79 ± 0.10
human ALAS2b,c	—	2.1 ± 0.4	15 ± 3	4.3 ± 0.6	0.030 ± 0.002
murine ALAS2d	—	8.0 ± 0.1	25 ± 4	1.3 ± 0.9	0.14 ± 0.02
R. capsuatus e	—	—	0.25 ± 0.009	0.36 ± 0.14	0.27 ± 0.09
R. sphaeroides f,g	—	—	0.2e–1.9f	0.5e–17f	0.12

^aSee Supplementary Information for details about data analysis and parameters. Heme-bound form has no catalytic activity as shown in Fig. 2B.

^bDucamp, S., et al.²⁵.

^cFratz, E. J., et al.²⁶.

^dLendrihas, T., et al.²⁷.

^eKaufholz, A. L., et al.¹⁶.

^fJordan, P. M. and A. Laghai-Newton²⁸.

^gBolt, E. L., et al.²⁹.