Table 3.

Product distributions catalyzed by the double mutant bimodular Pik system with non-natural extender units.^a

		PikAIII Y755V + PikAIV Y753V
	10-dMLa		Narbonolideb
Extender unit	3a-d	4a-d	5a-d + 6a-d	7a-d
Propargyl (a)	41.0%c	3.6%c	59.6%c	14.7%c
	(10.6)d		(2.5)d	(49.0)d
Ethyl (b)	8.0%c	1.8%c	49.1%c	17.4%c
	(61)d		(16)d	(24.9)d
Allyl (c)	3.7%c	4.3%c	16.7%c	3.3%c
	(>8,000)d		(3.9)d	(>3,300)d
Butyl (d)	N.D.	11.3%c	5.4%c	N.D.e
	(>11,300)d		(>5,400)d	-f

^aPercent of 3a-d or 4a-d out of all 10-dML products (1, 3a-d, and 4a-d)

^bPercent of (5a-d + 6a-d) or 7a-d out of all narbonolide products (2, 5a-d, 6a-d, and 7a-d).

^cError was ± 5% of indicated value.

^dFold increase calculated based on values from the wild-type system in Scheme 1. In the case of a product that was not detected with the wild-type enzyme, the fold increase was calculated based on the limit of detection, 0.001% of total products.

^eN.D. = Not detected

^fNot applicable