tokens: The promoter of the major histocompatibility class II gene DRA contains an octamer element ( ATTTGCAT ) that is required for efficient DRA expression in B cells .
folded_tokens: the promoter of the major histocompatibility class ii gene dra contains an octamer element ( atttgcat ) that is required for efficient dra expression in b cells .
labels: O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region B-DNA_domain_or_region O O B-DNA_domain_or_region I-DNA_domain_or_region O B-polynucleotide O O O O O O B-DNA_domain_or_region O O B-cell_type I-cell_type O