In previous work , we identified an essential site in the c-sis/PDGF-B promoter , Tax-responsive element 1 ( TRE1 ) , necessary for transactivation by Tax .
in previous work , we identified an essential site in the c-sis/pdgf-b promoter , tax-responsive element 1 ( tre1 ) , necessary for transactivation by tax .
O O O O O O O O O O O B-protein_molecule O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O B-DNA_domain_or_region O O O O O O B-protein_molecule O