Table 1.

Kinetic parameters of PA3455 and SMc02148 with various substrates

Variable substrate	Constant substrate	Km, μM	kcat, s−1	kcat/Km, M−1·s−1
PA3455 wt*
Poly-P	AMP	62 ± 4.4	37.7 ± 1.2	6.1 × 105
Poly-P(3)	AMP	110 ± 20	3.4 ± 1.3	0.3 × 105
Poly-P	GMP	25 ± 2.0	6.7 ± 0.2	2.7 × 105
Poly-P(3)	GMP	55 ± 15	1.9 ± 0.1	0.4 × 105
AMP	Poly-P	820 ± 40	44.6 ± 0.8	0.5 × 105
GMP	Poly-P	1,550 ± 120	13.4 ± 0.4	0.9 × 104
Mg2+	AMP/Poly-P	940 ± 20	40.1 ± 0.4	0.4 × 105
Mg2+	GMP/Poly-P	2,060 ± 150	13.0 ± 0.5	0.6 × 104
PA3455-C‡
Poly-P	AMP	18 ± 3.0	2.3 ± 0.1	1.3 × 105
Poly-P	GMP	26 ± 3.6	0.4 ± 0.02	1.5 × 104
AMP	Poly-P	3,340 ± 700	6.4 ± 0.7	0.2 × 104
GMP	Poly-P	1,220 ± 90	0.4 ± 0.01	0.3 × 103
Mg2+	AMP/Poly-P	3,670 ± 200	4.1 ± 0.2	0.1 × 104
Mg2+	GMP/Poly-P	2,050 ± 480	0.3 ± 0.04	0.2 × 103
SMc02148 wt
Poly-P	ADP	21 ± 3.9	8.6 ± 0.2	4.1 × 105
ADP	Poly-P	32 ± 4.1	7.6 ± 0.01	2.4 × 105
GDP	Poly-P	520 ± 70	0.8 ± 0.03	0.2 × 104
Mg2+	ADP/Poly-P	4,200 ± 300	8.3 ± 0.3	0.2 × 104
SMc02148 W194A
Poly-P	ADP	50 ± 20	2.3 ± 0.1	4.6 × 104
ADP	Poly-P	380 ± 30	1.4 ± 0.03	0.4 × 104
SMc02148 Y233A
Poly-P	ADP	20 ± 6.1	5.0 ± 0.2	2.5 × 105
ADP	Poly-P	110 ± 10	2.1 ± 0.04	1.9 × 104

Poly-P_(12–13) from Sigma was used in all experiments (if not stated otherwise).

*Full-length WT protein (496 amino acids).

^†C-terminal PPK2 domain (amino acids 270–496).