Table 1.

Summary of TC motif insertion sites tested in SINV capsid protein

Insert region on capsid protein and insertion	Virus growthd	Labeling efficiencye
Capsid N terminus
(−1)-TCa	WT	Loses the TC tag
(−1)-TC-Lb	WT	+
Protease domainc
D113-TC	1 log lower	++
E176-TC	2 logs lower	NA
S182-TC	5 logs lower	NA
E186-TC	6 logs lower	++++
S199-TC	>7 logs lower	NA
E259-TC	>7 logs lower	NA
N terminal to protease domainc
E89-TC	WT	++
Q94-TC	WT	+++
K97-TC	WT	+++
G101-TC	WT	++

^aThe TC motif plus an N-terminal ATG codon was introduced just before the first amino acid (methionine) of the capsid protein.

^bThe TC motif plus an N-terminal ATG codon and a C-terminal GSSGGSSGGSSG flexible linker region was introduced before the first amino acid of the capsid protein.

^cThe TC motif was introduced directly after the indicated residue.

^dThe growth of all TC insertion mutants was compared to that of WT SINV at 24 h postelectroporation (see Materials and Methods). The log of the WT SINV titer was ∼8.6 as measured by plaque assay on BHK-21 cells. The titer of all mutants designated WT was >8.

^eThe labeling efficiency of virus-infected Vero cells with biarsenical dyes. NA, not applicable; +, barely detectable fluorescence; ++, low fluorescence intensity; +++, strong fluorescence intensity; ++++, very bright fluorescence intensity.