PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Medicago truncatula
HD-ZIP Family
Species TF ID Description
Medtr6g007647.2HD-ZIP family protein
Medtr6g007647.1HD-ZIP family protein
Medtr8g468210.1HD-ZIP family protein
Medtr5g038280.1HD-ZIP family protein
Medtr5g039000.1HD-ZIP family protein
Medtr6g011610.2HD-ZIP family protein
Medtr6g011610.1HD-ZIP family protein
Medtr4g107650.1HD-ZIP family protein
Medtr4g100550.1HD-ZIP family protein
Medtr8g469430.1HD-ZIP family protein
Medtr7g093430.1HD-ZIP family protein
Medtr2g061030.1HD-ZIP family protein
Medtr8g089895.1HD-ZIP family protein
Medtr4g097600.1HD-ZIP family protein
Medtr1g054285.1HD-ZIP family protein
Medtr8g006705.1HD-ZIP family protein
Medtr5g013010.1HD-ZIP family protein
Medtr3g080100.2HD-ZIP family protein
Medtr3g080100.1HD-ZIP family protein
Medtr3g086790.1HD-ZIP family protein
Medtr5g014890.1HD-ZIP family protein
Medtr3g103590.1HD-ZIP family protein
Medtr3g092150.1HD-ZIP family protein
Medtr1g017090.1HD-ZIP family protein
Medtr7g010020.1HD-ZIP family protein
Medtr1g061660.1HD-ZIP family protein
Medtr4g084750.1HD-ZIP family protein
Medtr7g103340.1HD-ZIP family protein
Medtr4g126900.1HD-ZIP family protein
Medtr8g026960.1HD-ZIP family protein
Medtr5g019680.1HD-ZIP family protein
Medtr5g019650.1HD-ZIP family protein
Medtr2g038580.1HD-ZIP family protein
Medtr2g038625.1HD-ZIP family protein
Medtr5g013010.2HD-ZIP family protein
Medtr2g101720.1HD-ZIP family protein
Medtr4g047800.1HD-ZIP family protein
Medtr2g088470.1HD-ZIP family protein
Medtr8g432540.1HD-ZIP family protein
Medtr7g076080.1HD-ZIP family protein
Medtr8g013980.1HD-ZIP family protein
Medtr3g109800.2HD-ZIP family protein
Medtr3g109800.4HD-ZIP family protein
Medtr2g101190.1HD-ZIP family protein
Medtr3g109800.1HD-ZIP family protein
Medtr1g101280.1HD-ZIP family protein
Medtr6g477820.1HD-ZIP family protein
Medtr2g030130.1HD-ZIP family protein
Medtr0198s0030.1HD-ZIP family protein
Medtr7g427710.1HD-ZIP family protein
Medtr5g005600.1HD-ZIP family protein
Medtr4g058970.1HD-ZIP family protein
Medtr2g094520.1HD-ZIP family protein
Medtr5g029320.1HD-ZIP family protein
Medtr2g030570.1HD-ZIP family protein
Medtr2g030600.1HD-ZIP family protein
Medtr2g030660.1HD-ZIP family protein
Medtr7g427700.1HD-ZIP family protein
HD-ZIP Family Introduction

A homeobox (HB) encodes a protein domain, the homeodomain (HD), which is a conserved 60-amino acid motif present in transcription factors found in all the eukaryotic organisms. This 60-amino acid sequence folds into a characteristic three-helix structure that is able to interact specifically with DNA. Most HDs are able to bind DNA as monomers with high affinity, through interactions made by helix III (the so-called recognition helix) and a disordered N-terminal arm located beyond helix I. The high degree of conservation of this type of domain among diverse proteins from different kingdoms indicates that this structure is crucial to maintain the HD functionality and that the role played by this domain is vital.

Members of the HD-Zip family have a leucine zipper motif (LZ) immediately downstream of the HD. The two motifs are present in transcription factors found in species belonging to other eukaryotic kingdoms, but their association in a single protein is unique to plants. The HD is responsible for the specific binding to DNA, whereas LZ acts as a dimerization motif. HD-Zip proteins bind to DNA as dimers, and the absence of LZ absolutely abolishes their binding ability, which indicates that the relative orientation of the monomers, driven by this motif, is crucial for an efficient recognition of DNA.

Ariel FD, Manavella PA, Dezar CA, Chan RL.
The true story of the HD-Zip family.
Trends Plant Sci, 2007. 12(9): p. 419-26.
PMID: 17698401