FIG. 1.

Characterization of a novel TFIIB-related protein in A. thaliana. (A) Schematic representation of A. thaliana TFIIB (AtTFIIB)-related proteins. Percentages refer to identities between human TFIIB (HsTFIIB) and Arabidopsis TFIIB, Brf, and pBrp proteins. The putative zinc ribbon domain, the imperfect direct repeats, and the carboxy-terminal P/E/D/S/T-rich domain are indicated. (B) Primary sequence of A. thaliana pBrp. The metal-coordinating cysteine residues of the putative zinc ribbon domain are in boldface. The two imperfect direct repeats are underlined. (C) A. thaliana pBrp can substitute for human TFIIB or A. thaliana TFIIB2 in stabilizing the interaction between A. thaliana TBP2 and the adenovirus major late promoter in gel shift assay. Additions to each reaction mixture are listed above each lane. FP, free probe.