Thus , Sp1 and Egr-1 physically and functionally cooperate to mediate maximal IL-2Rbeta promoter activity .
thus , sp1 and egr-1 physically and functionally cooperate to mediate maximal il-2rbeta promoter activity .
O O B-protein_molecule O B-protein_molecule O O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region O O