tokens: Analysis of the 5 ' and 3 ' termini of the transcripts produced in vivo from the puf operon of R . sphaeroides PUF delta 348 - 420 ( three transcripts ; 0 . 59 , 0 . 64 , and 2 . 63 kilobases ) lacking the puf - intercistronic terminator structure were identical to those of the corresponding puf transcripts derived from wild - type R . sphaeroides 2 . 4 . 1 ( four transcripts ; 0 . 50 , 0 . 66 , 0 . 71 , and 2 . 7 kilobases ) showing that the transcripts begin and end at the same sites .