Table 1.

Creation of viral variants by site-directed mutagenesis^a

Variant	Modification	Template plasmid	Forward primer
pB-C3-SbfI	Create SbfI site	pB-C3	5′CCCTATAGTACAGAACCTGCAGGGGCAAATGGTGCATCAG3′
pB-C3-SbfI-MscI	Create MscI site	pB-C3-SbfI	5′GTCAGGGAGTGGGGGGACCTGGCCATAAAGCAAGAG3′
pB-NL-C3-R	D248G	pB-NL-C3-SbfI-MscI	5′GTACCCTTCGGGAACAAATAGGTTGGATGACAAGTAATCCACC3′
pB-NL-C3-0	R244Q	pB-NL-C3-R	5′CAGGAACTACTAGTACCCTTCAGGAACAAATAGGTTGGATGAC3′
pB-NL-C3-NR	T242N	pB-NL-C3-R	5′CATAGCAGGAACTACTAGTAACCTTCGGGAACAAATAGGTTGG3′
pB-NL-C3-N	T242N	pB-NL-C3-0	5′CATAGCAGGAACTACTAGTAACCTTCAGGAACAAATAGGTTGG3′

^aThe SbfI (CCTGCAGG) and MscI (TGGCCA) restriction sites or the codon modified by mutagenesis are underlined. The nucleotides modified in the target sequences are shown in bold. Only the forward primer is shown in the table; the reverse primer was the reverse complement of the forward primer.