tokens: By promoter deletion and mutation analyses , we established this region as a positive regulatory element .
folded_tokens: by promoter deletion and mutation analyses , we established this region as a positive regulatory element .
labels: O B-other_name I-other_name O B-other_name I-other_name O O O O O O O B-DNA_family_or_group I-DNA_family_or_group I-DNA_family_or_group O