tokens: In addition to the bZIP protein Opaque2 ( O2 ) , there are other maize endosperm nuclear proteins that recognize the O2 box in 22 kDa zein gene promoters .
folded_tokens: in addition to the bzip protein opaque2 ( o2 ) , there be other maize endosperm nuclear protein that recognize the o2 box in 22 kda zein gene promoter .