Table 3.

In vitro substrate specificities of wild-type and A479X mutants of PhaC_Cs

PHA synthasea	Value for substrateb
	(R)-3HB-CoAc		(R)-3HV-CoAc		(R)-3HHx-CoAd
	Sp act (U/mg)e	Relative sp act (%)f	Sp act (U/mg)	Relative sp act (%)	Sp act (U/mg)	Relative sp act (%)
Wild type	253 ± 13	100 ± 5	442 ± 81	100 ± 18	11 ± 1	100 ± 9
A479E	338 ± 38	134 ± 15	589 ± 55	133 ± 13	9 ± 2	82 ± 18
A479T	236 ± 8	93 ± 3	380 ± 20	86 ± 5	14 ± 1	127 ± 9
A479S	228 ± 19	90 ± 8	296 ± 25	67 ± 6	20 ± 3	182 ± 27

^aIsolated from E. coli BL21(DE3) and purified by affinity chromatography using a Strep-Tactin column.

^bA final concentration of 600 μM was used in each assay. The data shown are means of triplicate experiments.

^cPolymerization catalyzed by 7.5 nM, 15 nM, and 30 nM enzyme, respectively, in each of three assays performed.

^dPolymerization catalyzed by 100 nM, 200 nM, and 300 nM enzyme, respectively, in each of three assays performed.

^eOne unit of enzyme activity is defined as the amount of enzyme that catalyzed the release of 1 μmol CoA per minute.

^fPercentage relative to the activity of wild-type PhaC_Cs for the polymerization of each substrate.