to examine whether upstream or downstream measuring functions analogous to the tata box play roles in positioning the 5 ' ends of these rnas , we determined by s1 and primer extension mapping the locations of the 5 ' ends of the late viral rnas made in monkey cells infected with : ( i ) three wild-type strains of sv40 that contain tandem duplications of the enhancer region that are 64 , 85 , and 91 , rather than 72 , base pairs in length ;
C0080206
tata box
C0007634
cells