AINTEGUMENTA utilizes a mode of DNA recognition distinct from that used by proteins containing a single AP2 domain.
The Arabidopsis protein AINTEGUMENTA (ANT) is an important regulator of organ growth during flower development. ANT is a member of the AP2 subclass of the AP2/ERF family of plant-specific transcription factors. These proteins contain either one or two copies of a DNA-binding domain called the AP2 domain. Here, it is shown that ANT can act as a transcriptional activator in yeast through binding to a consensus ANT-binding site. This activity was used as the basis for a genetic screen to identify amino acids that are critical for the DNA binding ability of ANT. Mutants that showed reduced or no activation of a reporter gene under the control of ANT-binding sites were identified. The mutations identified in the screen as well as additional site-directed mutations suggest that the mode of DNA recognition by members of the AP2 subfamily is distinct from that of ERF proteins. Surprisingly, it appears that each AP2 domain of ANT uses different amino acids to contact DNA. Identification of several linker mutations argues that this sequence acts in the positioning of each AP2 domain on the DNA or makes direct DNA contacts.
Krizek
Beth A
BA
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA. krizek@sc.edu
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D015966:Gene Expression Regulation, Fungal; D007763:Lac Operon / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
C099055:AINTEGUMENTA protein, Arabidopsis; D029681:Arabidopsis Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D014157:Transcription Factors