The Tat protein of human immunodeficiency virus type 1 ( HIV-1 ) is a potent activator of long terminal repeat -directed transcription .
the tat protein of human immunodeficiency virus type 1 ( hiv-1 ) is a potent activator of long terminal repeat -directed transcription .
O B-protein_molecule I-protein_molecule O B-virus I-virus I-virus I-virus I-virus O B-virus O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O O O