Abstract
The nuclear single-stranded DNA binding factor (NssBF) has been characterized as a nuclear protein that binds to a 26 nucleotides sequence in the long terminal repeat (LTR) of the Drosophila melanogaster 1731 retrotransposon. This sequence, called NssBF element, was analysed by gel retardation experiments using wild-type and mutated oligonucleotides. In vitro transcription experiments were performed and suggest that NssBF element binding protein(s) represses transcription through the 1731 promoter. Furthermore, computer assisted sequence comparisons put forward a possible role of this element and/or its associated DNA binding proteins in replication.
