Characterization of the beta-lactamase promoter of pBR322.

AUTOR(ES)

Russell, D R

RESUMO

The beta-lactamase promoter of pBR322, derived from Tn3, has been characterized using several techniques. The transcription initiation site is located 35 base pairs from the translation initiation codon of beta-lactamase. The mRNA produced in vitro has a 5' pppGpA terminus. RNA polymerase bound at this start site protects a region from about -50 to +20 from DNase I cleavage using the footprinting technique. RNA polymerase binds rapidly to the beta-lactamase promoter. The half-time of association is less than one-half minute. The half-time of dissociation is approximately 6 hr. A study of the binding of RNA polymerase at different temperatures showed a large change between 11 degrees and 15 degrees C. Comparison of these parameters with those reported for other promoters is discussed.

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