Computational Analysis Of Homeodomain-Leucine Zipper (Hd-Zip) Family Of Transcription Factors In Arabidopsis Thaliana

Homeodomain-leucine Zipper (HD-Zip) proteins are a class of transcription factors having conserved homeodomain. Homeo box, conserved part of homeodomain consists of 56 residues and is involved in plant development. We retrieved protein sequences of all the 48 HD-Zip family members, performed genome-wide analysis, and grouped them into four subfamilies. A comprehensive genomic analysis including mapping of all the transcription factors on 5 chromosomes of Arabidopsis thaliana, multiple sequence alignment to find out the conserved domains, phylogenetic, and gene structure analysis by mapping introns and exons, promoter analysis by taking 1000bp upstream genomic sequence of all these transcription factors and motif analysis was performed in this study. The results helped us to understand the functional homology among HD-Zip transcription factors, comparison of the tree with motifs that further depends upon the number of exons and introns. This classification and analysis further categorized the transcription factors of 4 HD-Zip subfamilies into different classes and revealed a deep evolutionary relationship among them and thus helped to further explore theirMany biological processes such as development, growth, cell division and response against stress or environmental stimuli in organisms/cells are controlled by transcription factors (Shen et al., 2019). Transcription factors (TFs) bind to the DNA and either up-regulate or down-regulate gene expression at the transcriptional level (Todaka et al., 2015). There are more than 60 families of TFs in plants having different functions. The homeo-box (HB) family of TFs has a sub-family of homeodomainleucine-zipper (HD-Zip) proteins that have been reported in Arabidopsis thaliana and many other plants. The HB is an important transcription factor family consisting of the homeodomain (HD) which binds to DNA at a specific site and a leucine zipper that acts as a dimerization motif