Plant Transcription Factor Database
Previous version: v3.0
Aegilops tauschii
HD-ZIP Family
Species TF ID Description
EMT09606HD-ZIP family protein
EMT21095HD-ZIP family protein
EMT09592HD-ZIP family protein
EMT18359HD-ZIP family protein
EMT25510HD-ZIP family protein
EMT19543HD-ZIP family protein
EMT01252HD-ZIP family protein
EMT18149HD-ZIP family protein
EMT21390HD-ZIP family protein
EMT01676HD-ZIP family protein
EMT32685HD-ZIP family protein
EMT27141HD-ZIP family protein
EMT03764HD-ZIP family protein
EMT29383HD-ZIP family protein
EMT20928HD-ZIP family protein
EMT21303HD-ZIP family protein
EMT01310HD-ZIP family protein
EMT33138HD-ZIP family protein
EMT22839HD-ZIP family protein
EMT22881HD-ZIP family protein
EMT11484HD-ZIP family protein
EMT33784HD-ZIP family protein
EMT11763HD-ZIP family protein
EMT25632HD-ZIP family protein
EMT02636HD-ZIP family protein
EMT24595HD-ZIP family protein
EMT03247HD-ZIP family protein
EMT05677HD-ZIP family protein
EMT15044HD-ZIP family protein
EMT18268HD-ZIP family protein
EMT09665HD-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