Figure 2.4-A. Schematic of the adenoviral construction base plasmid, pS2. 
In addition to prokaryotic elements including an ampicillin resistance gene 
(AMP r ) , and fl and Col El origins of replication and the T3 and T7 RNA 
promoters, the plasmid contains left end elements of adenovirus type 5 
including the left inverted terminal repeat (ITR) and origin of replica- 
tion, Ela enhancer and encapsidation signal (VO , and elements to control 
the expression of an exogenous cDNA including the major late promoter (MLP) 
and tripartite leader elements 1,2 and 3. This is followed by a multiple 
cloning site and a segment of adenovirus type 5 [from position 9.24 map 
units (ra.u.) to 17.34 m.u. (6241 bp)] used for vector construction by 
homologous recombination. 
Tripartite leader 
Xbal 
Spel 
Bam HI 
Eco Rl 
Eco RV 
Cla I 
Sal I 
— Ad5 #3328 
(9.24 m.u.) 
Kpn 
Ad5 #6241 
(17.34 m.u.) 
Left ITR 
Origin of replication 
Not I 
Ela promoter/enhancer and i]> 
Major late promoter 
[664] 
Recombinant DNA Research, Volume 16 
