Table 1.

The replicase gene products of severe acute respiratory syndrome coronavirus.

Protein	Position in polyproteins pp1a and pp1aba, respectively		Protein size (amino acid residues)a	Featuresa,b
nsp1	Met1	–Gly180	180	ND
nsp2	Ala181	–Gly818	638	ND
nsp3	Ala819	–Gly2740	1922	Acidic domain, ADP-ribose 1″-phosphatase, papain-like protease 2 (C/H), Y domain (TM1, C/H)
nsp4	Lys2741	–Gln3240	500	TM2
nsp5	Ser3241	–Gln3546	306	3C-like protease
nsp6	Gly3547	–Gln3836	290	TM3
nsp7	Ser3837	–Gln3919	83	ND
nsp8	Ala3920	–Gln4117	198	ND
nsp9	Asn4118	–Gln4230	113	ssRNA-binding proteinc
nsp10	Ala4231	–Gln4369	139	C/H
nsp11	Ser4370	–Val4382	13	ND
nsp12	Ser4370	–Gln5301	932	RNA polymerase
nsp13	Ala5302	–Gln5902	601	C/H, NTPase, dNTPase, 5′-to-3′ RNA helicase and DNA helicase, RNA 5′-triphosphatased
nsp14	Ala5903	–Gln6429	527	3′-to-5′ exoribonuclease, C/H
nsp15	Ser6430	–Gln6775	346	uridylate-specific endoribonuclease
nsp16	Ala6776	–Asn7073	298	2′-O-ribose methyltransferase

C/H, domain with conserved Cys/His residues; ND, no data; TM, transmembrane domain;. ^aData from Snijder et al. [16^••]. ^bData from Ziebuhr [28]. ^cData from Sutton et al. and Egloff et al. 53., 54.. ^dData from Ivanov et al. [42].