Characterization of a protein that binds to AT-rich DNA in a seed nuclear extract of winged bean [ Psophocarpus tetragonolobus (L.) DC. cv. Ishigaki-4]

• Published in: Journal of plant physiology Vol. 152; no. 1; pp. 10 - 16
• Main Authors: Habu, Yoshiki, Fukasawa, Kazuhiro, Furuya, Shigeki, Matsumoto, Daisuke, Ohno, Takeshi
• Format: Journal Article
• Language: English
• Published: Jena Elsevier GmbH 1998; Elsevier
• Subjects: Analytical, structural and metabolic biochemistry; AT-rich sequences; Binding and carrier proteins; Biological and medical sciences; DNA-binding proteins; Fundamental and applied biological sciences. Psychology; HMG-like proteins; Holoproteins; Kunitz proteinase inhibitor; Nuclear proteins; Proteins; Psophocarpus tetragonolobus (L.) DC. cv. Ishigaki-4; HMG; LMC; HMG-like proteins; WTCI; Kunitz proteinase inhibitor; WTI; AT-rich sequences; B3F; B1F; WCI; DNA-binding proteins; Psophocarpus tetragonolobus (L.) DC. cv. Ishigaki-4; HMC; Characterization; Psophocarpus tetragonolobus; Grain legume; Specificity; Seeds; Leguminosae; Nucleotide sequence; Dicotyledones; Cell nucleus; Angiospermae; DNA binding protein; Spermatophyta
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/S0176-1617(98)80095-3

The organ-specific and temporally regulated expression of the genes for Kunitz chymotrypsin inhibitor-3 in winged bean is known to be governed by its 5′ flanking region. Two nuclear factors that bind to AT-rich sequences in this region were detected in gel retardation assays. The binding activity of one of these factors, band 1-forming factor, was inhibited by phosphorylation, as is the AT-binding protein ATBP-1 of tobacco, which functions as an activator of transcription. In addition, the binding of band 1-forming factor was reduced in the presence of a low concentration of the minor groove-binding dye, Hoechst 33258, suggesting that band 1-forming factor recognizes the minor groove of the probe, as does ATBP-1. The binding of another factor, band 3-forming factor, was also reduced by Hoechst 33258, but the binding activity of this factor was not affected by phosphorylation. During partial purification by gel-filtration and affinity chromatography, the binding activity of band 3-forming factor was cofractionated with a 75-ku (kDa) DNA-binding protein. These results indicate that band 3-forming factor is a new DNA-binding factor that recognizes the minor groove of AT-rich DNA.