Table 2.

Predicted end-products of proteolytic processing of the ECoV replicase polyproteins pp1a and pp1ab

Cleavage product	Nucleotide positiona	Polyprotein	Position in pp1a/pp1ab (aa)	Length (aa)	Putative funcitional domain(s)b	Putative proteases predicted to release protein from polyproteins
nsp1	210–941	pp1a/pp1ab	1Met-Gly244	244		PL1pro
nsp2	942–2744	pp1a/pp1ab	245Val-Ala845	601		PL1pro
nsp3	2745–8597	pp1a/pp1ab	846Gly-Gly2796	1951	Ac, PL1pro, ADRP, PL2pro, TM1, Y	PL2pro
nsp4	8598–10,085	pp1a/pp1ab	2797Ala-Gln3292	496	TM2	PL2pro + 3CLpro
nsp5	10,086–10,994	pp1a/pp1ab	3293Ser-Gln3595	303	3CLpro	3CLpro
nsp6	10,995–11,855	pp1a/pp1ab	3596Ser-Gln3882	287	TM3	3CLpro
nsp7	11,856–12,122	pp1a/pp1ab	3883Ser-Gln3971	89	Part of RNA binding hexadecameric supercomplex	3CLpro
nsp8	12,123–12,713	pp1a/pp1ab	3972Ala-Gln4168	197	Part of RNA binding hexadecameric supercomplex	3CLpro
nsp9	12,714–13,043	pp1a/pp1ab	4169Asn-Gln4278	110	ssRNA-binding protein	3CLpro
nsp10	13,044–13,454	pp1a/pp1ab	4279Ala-Gln4415	137	2 zinc fingers	3CLpro
nsp11	13,455–13,496	pp1a	4416Ser-Ser4429	14		3CLpro
nsp12	13,455–16,237	pp1ab	4416Ser-Gln5343	928	RdRp	3CLpro
nsp13	16,238–18,034	pp1ab	5344Ser-Gln5942	599	ZBD, HEL	3CLpro
nsp14	18,035–19,597	pp1ab	5943Cys-Gln6463	521	Exonuclease (ExoN)	3CLpro
nsp15	19,598–20,695	pp1ab	6464Ser-Gln6829	366	NendoU	3CLpro
nsp16	20,696–21,592	pp1ab	6830Ala-Ile7128	299	2′-O-MT	3CLpro

Domains Ac and Y are described by Ziebuhr et al. (2001).

^aNucleotide position means the location of the nucleotides encoding corresponding proteins in the entire genome of equine coronavirus-NC99 strain.

^bPL1^pro, papain-like proteinase 1; PL2^pro, papain-like proteinase 2; ADRP, adenosine diphosphate-ribose 1ʺ-phosphatase (formerly known as ‘X-domain’); 3CL^pro, 3C-like proteinase; TM, transmembrane domain; GFL, growth factor-like domain; RdRp, RNA-dependent RNA polymerase; ZBD, zinc-binding domain; HEL, helicase domain; NendoU, nidoviral uridylate-specific endoribonuclease; 2′-O-MT, 2′-O-ribose methyltransferase.