Table 2. E2 envelope glycoprotein amino acid differences between enzootic and epizootic subtype IE VEEV viruses.

Nucleotide position*	E2 amino acid position	68U201	80U76	OAX142†	CPA152†	OAX131†	CPA201†
8923	117	Glu	—	—	Lys	Lys	Lys
9227‡	218	Ser	—	Asn	Asn	Asn	Asn
9703	377	Ile	Leu	—	—	—	—
9793	407	Ser	Arg	Arg	Arg	Arg	Arg

—, same amino acid residue as 68U201 strain.

^*Genomic nucleotide positions with nonsynonymous differences.

^†Viruses isolated during 1993 and 1996 Mexican equine epizootics.

^‡Bold text represents the single amino acid residue shared by all of the Mexican epizootic strains.