TABLE 1.

Mutation analysis of the proteinase domain of BYV L-Pro^legend

Classa	BYV variant	Mutation	Processing efficiencyb	GUS activityb
I	A14	R456A	100 ± 8	100 ± 13
	A15	E470A	67 ± 3	87 ± 10
	A16	Q481A	95 ± 5	95 ± 12
	A17	D492A	93 ± 4	125 ± 17
	A21	Q521A	99 ± 8	102 ± 15
	A23	K543A	95 ± 6	114 ± 13
	A24	H556A	72 ± 5	95 ± 10
	A25	R559A	81 ± 6	86 ± 10
	A27	S578A	104 ± 5	92 ± 11
II	A18	R503A	92 ± 7	43 ± 3
	A20	C517A	54 ± 4	27 ± 6
	A22	D529A	58 ± 4	2 ± 1
	A26	D571A	59 ± 3	3 ± 1
III	A13	D446A	97 ± 7	<0.001
	A19	C509A	UDc	<0.001

^aThe mutant variants are divided into classes according to the levels of GUS activity. These levels are ≥86% for class I, ≤2% for class II, and <0.001% for

^legendclass III.

^bExpressed as percentages of the levels found for the wild type. Means and standard deviations are shown.

^cUD, undetectable.