Nucleic Acids Research, 1991, Vol. 19, No. 3 517-524
© 1991
MOLECULAR BIOLOGY |
DNA protein interactions at the interferon-responsive promoter elements: potential for an H-DNA conformation
Laboratoire de Biochimie des Protéines, URA CNRS 1191, Université Montpellier II Place E. Bataillon CP012, 34095 Montpellier Cedex 5, France
*To whom correspondence should be addressed
Received November 6, 1990. Revised January 7, 1990. Accepted January 7, 1990.
The regions of several genes (IFI-56K, HLA-A3, HLA-DR and 6–16) containing the (putative) ISRE (Interferon Stimulatable Response Element) were tested for their ability to be recognized by HeLa cells nuclear extract proteins. In a band shift assay, all probes yielded two B1 and B2 DNA-protein complexes of similar mobilities. Unexpectedly the titratlon of the B1 complex with a synthetic ISRE core (OL1), promoted the formation of B2. Both the probe and OL1 were recovered in B2. For each probe, the possibility of the part of the sequence Involved in B1 complex to form a H-DNA structure with the part of the sequence Involved in B2 exists. Such a structure was favored by the colinearity of the pairing regions and requires ATP. Although probes seemed to have a secundary structure, the formal existence of a H-DNA structure has not been demonstrated.Such a model could be extended to other interferon inducible gene promoters and may account for their binding properties and differential inducibility after 5' deletion or point mutations.