N2 PROVIRUS 
s 
1 — ^ 
PPEP PXEC S 
1 1 ® ^P==l * 1 
LTR 5' 
1 1 
S' NEO” LTR 
1 1 1 1 1 1 1 
0 0.5 
1.0 1.5 ZO ZS 3.0 3.5 4.0 
SCALE IN Kb 
Recombinant DNA Research, Volume 14 
[15] 
