Table 1.

PCR primers for amplifying the SARS-CoV protein genes

Proteins	Region of genes	Primers
Spike protein—C terminal fragment	AA 668–1193	tttGGTCTCaaggtatgagtactagccaaaaatctattgtggc
		cgcGGATCCtcatttaatatattgctcatattttc
Nucleocapsid protein	Entire gene	tttGGTCTCaaggtatgtctgataatggaccccaatc
		cgcGGATCCtcatgcctgagttgaatcagcag
CL Protease	Entire gene	tttCGTCTCaaggtagtggttttaggaaaatggcattcccg
		cgcGGATCCtcattggaaggtaacaccagagc

Restriction enzyme recognition sites used for cloning are indicated in uppercase letters. Owing to the presence of a BsaI site within the 3CL protease coding sequences, a different restriction enzyme, Esp3I, was used at the 5′ end to join the BsaI site in the pET-SUMO vector.