PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Daucus carota
HD-ZIP Family
Species TF ID Description
DCAR_006726HD-ZIP family protein
DCAR_006725HD-ZIP family protein
DCAR_031059HD-ZIP family protein
DCAR_007141HD-ZIP family protein
DCAR_011209HD-ZIP family protein
DCAR_014200HD-ZIP family protein
DCAR_025369HD-ZIP family protein
DCAR_011144HD-ZIP family protein
DCAR_007131HD-ZIP family protein
DCAR_006848HD-ZIP family protein
DCAR_003466HD-ZIP family protein
DCAR_029770HD-ZIP family protein
DCAR_027755HD-ZIP family protein
DCAR_019849HD-ZIP family protein
DCAR_008517HD-ZIP family protein
DCAR_015704HD-ZIP family protein
DCAR_026075HD-ZIP family protein
DCAR_026596HD-ZIP family protein
DCAR_012883HD-ZIP family protein
DCAR_031035HD-ZIP family protein
DCAR_016533HD-ZIP family protein
DCAR_025834HD-ZIP family protein
DCAR_027400HD-ZIP family protein
DCAR_017227HD-ZIP family protein
DCAR_020355HD-ZIP family protein
DCAR_023600HD-ZIP family protein
DCAR_002986HD-ZIP family protein
DCAR_012829HD-ZIP family protein
DCAR_020787HD-ZIP family protein
DCAR_025935HD-ZIP family protein
DCAR_005003HD-ZIP family protein
DCAR_020042HD-ZIP family protein
DCAR_019572HD-ZIP family protein
DCAR_020998HD-ZIP family protein
DCAR_010783HD-ZIP family protein
DCAR_005004HD-ZIP family protein
DCAR_010930HD-ZIP family protein
DCAR_007570HD-ZIP family protein
DCAR_004202HD-ZIP family protein
DCAR_023074HD-ZIP family protein
DCAR_026332HD-ZIP family protein
DCAR_010210HD-ZIP family protein
DCAR_014006HD-ZIP family protein
DCAR_003857HD-ZIP family protein
DCAR_007844HD-ZIP family protein
DCAR_022744HD-ZIP family protein
DCAR_006066HD-ZIP family protein
DCAR_027865HD-ZIP family protein
DCAR_023260HD-ZIP family protein
DCAR_014738HD-ZIP family protein
DCAR_007580HD-ZIP family protein
DCAR_016046HD-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