TABLE 1.

Env amino acid differences of the three wild-type SIVsmE660 strains^a

Tier	Amino acid
	C1 at position:		V1 at position:			V2 at position:		V4 at position:
	45	70	134	139	140	184	185	420	425	429	432
1	T	S	T	A	A	R	I	K	K	T	R
2	A	N	I	A	S	R	I	K	R	M	Q
3	A	N	T	—	A	K	M	N	K	T	Q

^aAll of the amino acid differences among the three strains are shown. The locations of these differences are labeled by residue number as well as the domain in which they are found. C1 corresponds to constant region 1, and variable loops 1, 2, and 4 are labeled V1, V2, and V4, respectively. Residues that differ from the parental E660-FL14 tier 1 clone are in boldface type, and deletions are shown as a dash.