Table 1. AT-Exchanged PKSs Used in This Study.

PKSs	source bacteria	source genes	source of KAL-AT-PAL1s	natural substrates	purification yields (relative to WT)	abbreviations
DEBS M6 + TE	Saccharopolyspora erythraea NRRL 2338	eryAI		methylmalonyl-CoA	1.0	WT
1	Sorangium cellulosum SMP44	epoD	module 4	malonyl-CoAmethylmalonyl-CoA	0.7	Epo-4
2	Streptomyces cinnamonensis ATCC 15413	monAIV	module 5	methylmalonyl-CoAethylmalonyl-CoA	1.6	Mon-5
3	Streptomyces caelestis NRRL 2821	nidA3	module 5	ethylmalonyl-CoA	1.1	Nid-5
4	Streptomyces sp. SN-593	revA	module 4	butylmalonyl-CoAhexylmalonyl-CoA etc.	0.9	Rev-4
5	Streptomyces sp. W112	divB	module 4	ethylmalomyl-CoA	0.9	Div-4
6	Streptomyces sp. CNH-189	ansE	module 8	isobutylmalonyl-CoA	0.7	Ans-8
7	Streptomyces flaveolus DSM 9954	sfaI	module 13	3-oxobutylmalonyl-CoA	0.8	San-13
8	Sorangium cellulosum So ce690	leuA	module 2	1-hydroxyisopentylmalonyl-CoA	0.5	Leu-2
9	Streptomyces sp. W112	divD	module 6	isobutenylmalonyl-CoA	1.1	Div-6
10	Salinispora tropica CNB-476	salA	module 1	2-chloroethylmalonyl-CoA	0.1	Sal-1
11	Streptomyces ambofaciens ATCC 23877	pks4	module 12	hexylmalonyl-CoAisoheptylmalonyl-CoA etc.	0.1	Sta-12
12	Streptomyces sp. CNQ431	spnD	module 3	benzylmalonyl-CoA	0.3	Spl-3