Isolation and characterization of a fourth Arabidopsis thaliana G-box-binding factor, which has similarities to Fos oncoprotein.
A fourth member of the Arabidopsis G-box-binding factor (GBF) family of bZIP proteins, GBF4, has been isolated and characterized. In a manner reminiscent of the Fos-related oncoproteins of mammalian systems, GBF4 cannot bind to DNA as a homodimer, although it contains a basic region capable of specifically recognizing the G-box and G-box-like elements. However, GBF4 can interact with GBF2 and GBF3 to bind DNA as heterodimers. Mutagenesis of the leucine zipper of GBF4 indicates that the mutation of a single amino acid confers upon the protein the ability to recognize the G-box as a homodimer, apparently by altering the charge distribution within the leucine zipper.
Menkens
A E
AE
Department of Biology, University of Pennsylvania, Philadelphia 19104-6018.
Cashmore
A R
AR
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D051790:G-Box Binding Factors; D017343:Genes, Plant / Q000235:genetics*; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D016759:Oncogene Protein p65(gag-jun) / Q000235:genetics; D016761:Oncogene Proteins v-fos / Q000235:genetics; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D051790:G-Box Binding Factors; D016759:Oncogene Protein p65(gag-jun); D016761:Oncogene Proteins v-fos; D014157:Transcription Factors