Table 1.

Effect of certain amino acid substitutions in the AT₀ domain of NysA on the ability of the recombinant protein to restore nystatin biosynthesis in the S. noursei nysA mutant^a

AT0 mutation							KS mutation		Nystatin yield (% of WTb)
T56V	G57D	W58V	V89Q	H185Y	F187S	M117I	KSC	KSQ
x	x								46 ± 2
x	x	x							46 ± 4
x	x	x	x						51 ± 5
				x					82 ± 6
			x	x					55 ± 5
					x				72 ± 5
			x		x				62 ± 5
				x	x				22 ± 2
			x	x	x				2 ± 1
x	x	x	x	x					37 ± 4
x	x	x	x		x				10 ± 2
x	x	x	x	x	x				3 ± 1
x	x	x	x		x	x			11 ± 2
					x		x		41 ± 4
					x			x	72 ± 4
				x			x		72 ± 5
				x			x		0
				x	x		x		0
				x	x			x	17 ± 1
			x	x			x		93 ± 6

^a“x” indicates the presence of the mutation in the NysA domain. Note that the data represent an average from 3 parallel experiments. The NDA59 mutant complemented with the wild-type nysA gene was used as a reference.

^bWT, wild type.