The long terminl repeat(LTR) of the bovine foamy virus(BFV) contains the viral promoter,which is responsible for viral gene expression in eukaryotic cells We have demonstrated that BFV LTR linked to the luciferase gene can express the enzyme efficiently upon transformation into bacteria Deletion analysis and sequence comparison showed that the BFV LTR has a sequence(from-125 to-90)which is greatly homologous to the model bacteria promoter And the proposed transcriptional starting site is at the thymine of-91 or the cytosine of -92 Besides,being fully functional in E coli,the BFV LTR can also be specifically trans activated by BFV tas gene product,Borf-1 protein The responsive element lies between base -310 and -140,which is in accordance with the responsive region in eukaryotic cells The trans-activation of BFV LTR by Borf 1 protein in bacteria offers a useful system to investigate further the specific interaction between Borf-1 protein with BFV LTR and the mechanism of the trans
