PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Arabidopsis lyrata
HD-ZIP Family
Species TF ID Description
477377HD-ZIP family protein
476108HD-ZIP family protein
497511HD-ZIP family protein
496765HD-ZIP family protein
481105HD-ZIP family protein
908602HD-ZIP family protein
325972HD-ZIP family protein
490793HD-ZIP family protein
490960HD-ZIP family protein
904137HD-ZIP family protein
904139HD-ZIP family protein
481142HD-ZIP family protein
483619HD-ZIP family protein
896139HD-ZIP family protein
490837HD-ZIP family protein
914971HD-ZIP family protein
486512HD-ZIP family protein
472703HD-ZIP family protein
881859HD-ZIP family protein
494245HD-ZIP family protein
332898HD-ZIP family protein
346639HD-ZIP family protein
343486HD-ZIP family protein
486694HD-ZIP family protein
325029HD-ZIP family protein
860781HD-ZIP family protein
870000HD-ZIP family protein
476226HD-ZIP family protein
495477HD-ZIP family protein
491408HD-ZIP family protein
902559HD-ZIP family protein
324546HD-ZIP family protein
473277HD-ZIP family protein
314555HD-ZIP family protein
496218HD-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