TABLE 2.

Comparison of cleavage sites recognized by coronavirus PLP1 and PLP2 activities^d

Cleavage products	Amino acid at cleavage site position:								Reference(s)
	P6	P5	P4	P3	P2	P1	P1′	P2′
Cleaved by PLP1						↓
MHV p28/p65	L	K/Ra	G	Y	Ra	Ga	V	K	12, 20
MHV p65/p210	W	Ra	F	P	C	Aa	Ga	K	7
HCoV p9/p87	G	Ka	R	G	G	Ga	N	V	17
Cleaved by PLP1 and PLP2
HCoV p87/p210b	F	T	K	A	A	G	G	K	43
Cleaved by PLP2
IBV p87/p195c	V	V	C	K	A	Ga	G	K	25
IBV p195/p41c	V	E	K	K	Aa	Ga	G	I	26
MHV p210/p44	Fa	S	L	K	Ga	Ga	A	V	This paper

^aA critical determinant for PLP processing as determined by mutagenesis studies.

^bIn vitro transcription-translation studies indicate that both PLP1 and PLP2 can cleave at this site. Critical determinants have not been identified.

^cA revised alignment study indicates that the domain previously referred to as IBV PLPD has an inactive PLP1 domain and an active PLP2 domain (43).

^dThe arrow indicates where the polyprotein is cleaved.