Table 1.

Amino acid sequence of the E2 HS binding domain and specific infectivity and plaque sizes of viruses used in this study

Virus	E2 69–77 amino acid sequence	Isolatea	Specific infectivityb (PFU/μg)	Plaque sizec (mm)
WT	NGKTQKSIK	FL91-4679 and 42 others	1.0 ± 0.0	6.41 ± 0.44
E2 71-77A	NGATQASIA	Mutant	9.2 ± 1.4	4.24 ± 0.54
E2 71A	NGATQKSIK	Mutant	ND	ND
E2 74A	NGKTQASIK	Mutant	ND	ND
E2 77A	NGKTQKSIA	Mutant	ND	ND
E2 71Q	NGQTQKSIK	MA38, LA50	1.0 ± 0.4	3.81 ± 0.42
E2 71T	NGTTQKSIK	CT90, MS83	10.0 ± 1.4	4.00 ± 0.43
E2 72K	NGKKQKSIK	TX95	1.1 ± 0.2	1.87 ± 0.37

^aLetters represent the state where the virus was isolated; the numbers immediately after the state abbreviation represent the year of isolation (15–17).

^bRepresented as fold reduction in specific infectivity versus that of the WT. ND, not done.

^cND, not done.