Basic leucine zipper (bZIP) domain of Plant RF2-like transcription factors: a DNA-binding and dimerization domain
This subfamily is composed of plant bZIP transciption factors with similarity to Oryza sativa RF2a and RF2b, which are important for plant development. They interact with, as homodimers or heterodimers with each other, and activate transcription from the RTBV (rice tungro bacilliform virus) promoter, which is regulated by sequence-specific DNA-binding proteins that bind to the essential cis element BoxII. RF2a and RF2b show differences in binding affinities to BoxII, expression patterns in different rice organs, and subcellular localization. Transgenic rice with increased RF2a and RF2b display increased resistance to rice tungro disease (RTD) with no impact on plant development. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.
Jiyao W et al.(2023). "The conserved domain database in 2023.",