ZF-HD Transcription Factor Family
This group of sequences described by a 54-residue domain found in the N-terminal region of plant proteins, the vast majority
of which contain a ZF-HD class homeobox domain toward the C terminus. The region between the two domains typically is rich
in low complexity sequence.
A one-hybrid screen resulted in the cloning of four different members of a novel class of plant homeodomain proteins, which
are most likely involved in the mesophyll-specific expression of the C4 PEPCase gene in C4 species of the genus Flaveria.
Inspection of the homeodomains of the four proteins reveals that they share many common features with homeodomains described
so far, but there are also significant differences. Interestingly, this class of homeodomain proteins occurs also in
Arabidopsis thaliana and other C3 plants. One-hybrid experiments as well as in vitro DNA binding studies confirmed that
these novel homeodomain proteins specifically interact with the proximal region of the C4 PEPCase (C4 phosphoenolpyruvate
carboxylase) gene. The N-terminal domains of the homeodomain proteins contain highly conserved sequence motifs. Two-hybrid
experiments show that these motifs are sufficient to confer homo- or heterodimer formation between the proteins. Mutagenesis
of conserved cysteine residues within the dimerization domain indicates that these residues are essential for dimer
formation. Therefore, we designate this novel class of homeobox proteins ZF-HD, for zinc finger homeodomain protein. Our
data suggest that the ZF-HD class of homeodomain proteins may be involved in the establishment of the characteristic
expression pattern of the C4 PEPCase gene.
55 predicted putative ZF-HD TF peptide,
CDS, cDNA sequenecs;
blast HSP, and multiple sequence alignment.
ZF-HD_dimer domain peptide sequences with
alignment, and phylogeny tree
16 ZF-HD protein
and DNA
sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen on June 16, 2009.
