DNA sequence preference of the progesterone receptor.

Highly purified hen oviduct progesterone receptor A subunit was tested for binding to several chicken gene DNAs. Sequence preference detected by nitrocellulose filter adsorption of [32P]DNA fragments obtained from recombinant plasmids revealed a marked retention of certain DNA fragments. About a 10-fold preference was seen for DNA fragments flanking the 5' end of the steroid-regulated genes ovalbumin and gene Y. No preference was seen with analogous DNA fragments from chicken beta-globin and alpha-actin genes. Restriction endonuclease mapping suggests the presence of multiple receptor interaction sites flanking the 5' terminus of the ovalbumin gene. One of these preferential binding sites was localized between -135 and -247 base pairs upstream from the start of transcription. This region contains an 18-base-pair A + T-rich sequence, a likely candidate for the binding site itself, because earlier studies had shown receptor A to have marked preference for A + T-rich DNA.