Transcription factors regulate the expression of genes and are involved in the control of many intracellular processes. These factors can be defined as sequence-specific DNA-binding protein that recognize regulatory sequences in the promoter of a gene and modulate transcription interacting   with  basal components of  the transcriptional machinery. Most of  the  transcription  factors are grouped  into different families based on their type of DNA-binding domain (Schlögl, P. S. et al., 2004, Plant Sci. 167:583-595). The basic leucine zipper (bZIP) proteins form a large family of transcription regulators in plants and other eukaryotes. These proteins are characterized by a conserved region rich in basic amino acid residues that binds to the target DNA. BZIPs  also contain the leucine zipper region, formed by several heptad repeats of hydrophobic residues, responsible for bZIP interactions. The leucine zipper region is alpha-helical and is capable of dimer formation via coiled-coil arrangement. The dimerization process can regulate interaction between bZIP and the transcription pre-initiation complex and also modulates interaction with target DNA, becoming a mecanism of gene expression control. In this work, we present the cloning, expression and purification of a novel sugarcane bZIP (SCF12), in addition to an analysis of structural integrity by circular dichroism spectroscopy. Crystallographic and solution studies (SAXS)  are in progress.