PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Utricularia gibba
HD-ZIP Family
Species TF ID Description
678338204HD-ZIP family protein
678411904HD-ZIP family protein
678335571HD-ZIP family protein
678442830HD-ZIP family protein
678337921HD-ZIP family protein
678299059HD-ZIP family protein
678317403HD-ZIP family protein
678383610HD-ZIP family protein
678459084HD-ZIP family protein
678401468HD-ZIP family protein
678399881HD-ZIP family protein
678458266HD-ZIP family protein
678456866HD-ZIP family protein
678461473HD-ZIP family protein
678352371HD-ZIP family protein
678299372HD-ZIP family protein
678343827HD-ZIP family protein
678364978HD-ZIP family protein
678334583HD-ZIP family protein
678469456HD-ZIP family protein
678454023HD-ZIP family protein
678456285HD-ZIP family protein
678444242HD-ZIP family protein
678411305HD-ZIP family protein
678377746HD-ZIP family protein
678378202HD-ZIP family protein
678417204HD-ZIP family protein
678336918HD-ZIP family protein
678327226HD-ZIP family protein
678460504HD-ZIP family protein
678427195HD-ZIP family protein
678462164HD-ZIP family protein
678459578HD-ZIP family protein
678438585HD-ZIP family protein
678398020HD-ZIP family protein
678331508HD-ZIP family protein
678339453HD-ZIP family protein
678462432HD-ZIP family protein
678446797HD-ZIP family protein
678453621HD-ZIP family protein
678454369HD-ZIP family protein
678410217HD-ZIP family protein
678309177HD-ZIP family protein
678403572HD-ZIP family protein
678333077HD-ZIP family protein
678405766HD-ZIP family protein
678305242HD-ZIP family protein
678445090HD-ZIP family protein
678461538HD-ZIP family protein
678412434HD-ZIP family protein
678330589HD-ZIP family protein
678325266HD-ZIP family protein
678445398HD-ZIP family protein
678291327HD-ZIP family protein
678392773HD-ZIP family protein
678290611HD-ZIP family protein
678334936HD-ZIP family protein
678397013HD-ZIP family protein
678346564HD-ZIP family protein
678296954HD-ZIP family protein
678333334HD-ZIP family protein
678317811HD-ZIP family protein
678448878HD-ZIP family protein
678453069HD-ZIP family protein
678451443HD-ZIP family protein
678309655HD-ZIP family protein
678444174HD-ZIP family protein
678374037HD-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