The maize regulatory locus Opaque-2 encodes a DNA-binding protein which activates the transcription of the b-32 gene

EMBO J. 1991 Mar;10(3):617-24.


The maize locus, Opaque-2, controls the expression in developing endosperm of structural genes encoding a family of storage proteins, the 22 kd zeins, and an abundant albumin, termed b-32. It is shown that the promoter of the b-32 gene is activated in vivo in the presence of the O2 gene product and that the information necessary for this activation resides in a 440 bp DNA fragment containing five O2 binding sites (GATGAPyPuTGPu). Two of these sites are embedded in copies of the 'endosperm box', a motif thought to be involved in endosperm-specific expression, which is also represented in 22 kd zein promoters. The O2 protein is also shown to be capable of binding in vitro and activating in vivo, its own promoter.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • DNA-Binding Proteins / genetics*
  • Escherichia coli / genetics
  • Genes*
  • Genes, Regulator*
  • Glucuronidase / genetics
  • Glucuronidase / metabolism
  • Molecular Sequence Data
  • Plant Proteins*
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / isolation & purification
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / genetics*
  • Transcription, Genetic*
  • Zea mays / genetics*
  • Zea mays / metabolism
  • Zein / biosynthesis
  • Zein / genetics*
  • Zein / isolation & purification


  • DNA-Binding Proteins
  • Plant Proteins
  • Recombinant Fusion Proteins
  • Transcription Factors
  • opaque-2 protein, Zea mays
  • Zein
  • Glucuronidase