This requirement has been attributed to the activation of the transcription factor NF-kappa B , which synergizes with the constitutive transcription factor Sp1 to drive the HIV-1 promoter .
this requirement has been attributed to the activation of the transcription factor nf-kappa b , which synergizes with the constitutive transcription factor sp1 to drive the hiv-1 promoter .
O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group B-protein_molecule I-protein_molecule O O O O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group B-protein_molecule O O O B-virus O O