we demonstrate , using gel electrophoretic size analyses and nuclease s1 mapping procedures , that rna polymerase terminates rna synthesis in the vicinity of five positions 180 , 220 , 379 , 421 and 463 base-pairs downstream from the start point during transcription of lacz dna in vitro in the presence of rho factor .
C0035681
rna polymerase
C0040649
transcription