Faculty Opinions recommendation of The Arabidopsis NPR1 disease resistance protein is a novel cofactor that confers redox regulation of DNA binding activity to the basic domain/leucine zipper transcription factor TGA1.

A simple approach has been developed for the unambiguous identification and purification of sequence-specific DNA-binding proteins solely on the basis of their ability to bind selectively to their target sequences. Four independent methods were used to identify the promoter-specific RNA polymerase II transcription factor MLTF as a 46-kilodalton (kDa) polypeptide. First, a 46-kDa protein was specifically cross-linked by UV irradiation to a body-labeled DNA fragment containing the MLTF binding site. Second, MLTF sedimented through glycerol gradients at a rate corresponding to a protein of native molecular weight 45,000 to 50,000. Third, a 46-kDa protein was specifically retained on a biotin-streptavidin matrix only when the DNA fragment coupled to the matrix contained the MLTF binding site. Finally, proteins from the most highly purified fraction which were eluted and renatured from the 44- to 48-kDa region of a sodium dodecyl sulfate-polyacrylamide gel exhibited both binding and transcription-stimulatory activities. The DNA-binding activity was purified 100,000-fold by chromatography through three conventional columns plus a DNA affinity column. Purified MLTF was characterized with respect to the kinetic and thermodynamic properties of DNA binding. These parameters indicate a high degree of occupancy of MLTF binding sites in vivo.

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Redox Regulation of GA-binding Protein-α DNA Binding Activity

Journal of Biological Chemistry ◽

10.1074/jbc.271.41.25617 ◽

1996 ◽

Vol 271 (41) ◽

pp. 25617-25623 ◽

Cited By ~ 48

Author(s):

Mark E. Martin ◽

Yurii Chinenov ◽

Mi Yu ◽

Tonya K. Schmidt ◽

Xiu-Ying Yang

Keyword(s):

Dna Binding ◽

Redox Regulation ◽

Binding Protein ◽

Binding Activity ◽

Dna Binding Activity ◽

Ga Binding Protein

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Cloning and characterization of E2F-2, a novel protein with the biochemical properties of transcription factor E2F

Molecular and Cellular Biology ◽

10.1128/mcb.13.12.7802-7812.1993 ◽

1993 ◽

Vol 13 (12) ◽

pp. 7802-7812

Author(s):

M Ivey-Hoyle ◽

R Conroy ◽

H E Huber ◽

P J Goodhart ◽

A Oliff ◽

...

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Hela Cell ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Amino Acid Identity ◽

Biochemical Properties ◽

Binding Activity ◽

Dna Binding Activity ◽

Novel Protein

E2F is a mammalian transcription factor that appears to play an important role in cell cycle regulation. While at least two proteins (E2F-1 and DP-1) with E2F-like activity have been cloned, studies from several laboratories suggest that additional homologs may exist. A novel protein with E2F-like properties, designated E2F-2, was cloned by screening a HeLa cDNA library with a DNA probe derived from the DNA binding domain of E2F-1 (K. Helin, J. A. Lees, M. Vidal, N. Dyson, E. Harlow, and A. Fattaey, Cell 70:337-350, 1992). E2F-2 exhibits overall 46% amino acid identity to E2F-1. Both the sequence and the function of the DNA and retinoblastoma gene product binding domains of E2F-1 are conserved in E2F-2. The DNA binding activity of E2F-2 is dramatically enhanced by complementation with particular sodium dodecyl sulfate-polyacrylamide gel electrophoresis-purified components of HeLa cell E2F, and anti-E2F-2 antibodies cross-react with components of purified HeLa cell E2F. These observations are consistent with a model in which E2F binds DNA as a heterodimer of two distinct proteins, and E2F-2 is functionally and immunologically related to one of these proteins.

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