Nucleic Acids Research, 1989, Vol. 17, No. 18 7333-7344
© 1989
MOLECULAR BIOLOGY |
In vitro binding of the bacteriophage f1 gene V protein to the gene II RNA-operator and its DNA analog
The Rockefeller University, 1230 York Avenue New York, NY 10021, USA
*Present address: Laboratoire de Génétique Microbienne, Centre de recherche INRA, Domaine Vilvert, 78350 Jouy-en-Josas, France
Received May 15, 1989. Revised August 17, 1989. Accepted August 17, 1989.
We have investigated the binding of the f1 single-stranded DNA-binding protein (gene V protein) to DNA oligonucleotides and RNA synthesized in vitro. The first 16 nucleotides of the fI gene H mRNA leader sequence were previously identified as the gene II RNA-operator; the target to which the gene V protein binds to repress gene II translation. Using a gel retardation assay, we find that the preferential binding of gene V protein to an RNA carrying the gene II RNA-operator sequence is affected by mutations which abolish gene II translational repression in vivo. In vitro, gene V protein also binds preferentially to a DNA oligonucleotide whose sequence is the DNA analog of the wild- type gene II RNA-operator. Therefore, the gene V protein recognizes the gene II mRNA operator sequence when present in either an RNA or DNA context