tokens: The demonstration that nucleolin is a component of a B cell-specific complex that binds switch region sequences suggests that the G-rich switch regions may have evolved from rDNA .
folded_tokens: the demonstration that nucleolin is a component of a b cell-specific complex that binds switch region sequences suggests that the g-rich switch regions may have evolved from rdna .
labels: O O O B-protein_molecule O O O O O B-protein_complex I-protein_complex I-protein_complex O O O O O O O O B-DNA_domain_or_region B-DNA_domain_or_region I-DNA_domain_or_region O O O O B-DNA_family_or_group O