Trihelix Transcription Factor Family
The trihelix domain is characteristic of the trihelix family. The trihelix domain was extracted from known members of this
family in Nicotiana tabacum, Arabidopsis thaliana and Oryza sativa.
GT-2 is a plant transcriptional activator that contains two separate, but similar, trihelix DNA-binding domains. GT-1 is
similar to GT-2, although it contains only one of such domains. cDNAs that encode GT-2 were isolated from rice (OS-GT2) and
Arabidopsis (AT-GT2). Evidence is presented for the existence of an Arabidopsis gene family that is structurally related to
AT-GT2. Two members of this GT2-like family, AT-GTL1 and AT-GTL2, have been isolated and characterized. Their sequences
suggest that they evolved by a recent gene duplication event. Both AT-GT2 and AT-GTL genes contain an intron in the
amino-terminal trihelix motif, indicating that this DNA-binding domain resulted from exon shuffling. RNA gel blot analysis
using AT-GTL1 as a probe revealed four transcripts in the aerial part of the plant. All mRNA levels were significantly
higher in siliques, suggesting that this gene family may function in fruit and/or seed development. To date, DNA-binding
proteins characterized by the trihelix motif have been described only in plants, and may therefore be involved in
plant-specific processes. Our results show that in Arabidopsis thaliana, the trihelix motif is not restricted to the GT-1
and GT-2 DNA-binding proteins.
26 predicted putative Trihelix TF peptide,
CDS, and cDNA sequences,
blast HSP, and multiple sequence alignment in
Soy - TFKB.
25 Trihelix domain peptide sequences with alignment
and phylogeny tree.
32 Trihelix protein
and DNA
sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen on
July 15, 2009.
