IDENTIFICATION AND PURIFICATION OF 2 PROTEINS THAT RECOGNIZE THE ENHANCER SEQUENCE OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

Gel retardation assays with nuclear extracts from various cells and a double-stranded oligonucleotide representing the sequence of the HIV-1 enhancer revealed at least two proteins of 43 and 53K that interacted specifically with the HIV enhancer and differed from those reported b efore. A simple and fast procedure for purification of these proteins involving heparin-agarose and DNA affinity chromatography steps was de veloped. The electrophoretic data suggest that the proteins are suffic iently pure for sequencing once the procedure is scaled up.