The aim of my thesis is to extract desired biological product through heterologous expression in Escherichia Coli. The study focuses on the bZip transcriptional factors atfA and atfB and their subsequent purification through heterologous expresson. For this purpose, gene of interest for the transcription factors are isolated and inserted in host plasmid, which then multiplies and produces the protein. The protein product is identified and separated through Gel electrophoresis and chromatography. Finally, the pure protein is extracted for further analysis. Protein purification of this type is essential in determining the function which helps understand their role in an organism and how they interact within the cells.