In these cells , nuclear factors involved in activation of the HIV-1 LTR , which contains the transcriptional control elements of the virus , are unknown .
in these cells , nuclear factors involved in activation of the hiv-1 ltr , which contains the transcriptional control elements of the virus , are unknown .
O O O O B-protein_family_or_group I-protein_family_or_group O O O O O B-DNA_domain_or_region I-DNA_domain_or_region O O O O B-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group O O O O O O O