A small monomeric G protein of the Ras superfamily, Dexras1, involved in cellular signal transduction processes of various pathophysiological processes and interacts with several proteins. Most of these molecular interactions of Dexras1 are attributed to the C-Terminus, but the N-Terminus has not been explored well due to the limited knowledge of its structure and the unavailability of 3D structure Protein Data Bank file in the databases. Our previous studies with in silico homology modeling predicted a structural model of Dexras1 protein and in continuation; the present study was focused on in vitro sub-cloning, expression, and purification of Dexras1 protein to analyze the structural determinants of its N-terminal region. Dexras1 gene was sub-cloned in a customized 6× His tag Maltose Binding Protein vector and expressed in the Escherichia coli BL21 strain. SDS-PAGE analysis suggested that Dexras1 protein was expressed as an insoluble fraction and found the best expression with 1 mM IPTG induction at 37°C for 3–4 h. Then, the expressed protein was purified using Nickel-Nitriloacetic acid resins and analyzed by a circular dichroism (CD) for structural determinants. Spectra obtained by CD outlines preliminary structural information which showed the presence of alpha-helix and beta-sheets in the entire protein, but the N terminus might primarily exist in a non-randomized domain that could have independent functions.
Key words: Key words: Dexras1, G protein, Expression, Purification, Sub-cloning, solubility fractions
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