tokens: To test these hypotheses , we studied several tat mutants , including two stop codon mutants and one deletion mutant using replication-competent HIV-1 constructs carrying wild-type or mutant LTRs with modifications in the NF-kappa B and/or Sp1 binding sites .
folded_tokens: to test these hypotheses , we studied several tat mutants , including two stop codon mutants and one deletion mutant using replication-competent hiv-1 constructs carrying wild-type or mutant ltrs with modifications in the nf-kappa b and/or sp1 binding sites .
labels: O O O O O O O O B-protein_family_or_group I-protein_family_or_group O O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O O B-protein_family_or_group I-protein_family_or_group O B-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group O O O O O O O O O O O O O O O O