Molecular Cloning and Characterization of the Gene Encoding Heat Shock Protein 70 from the Chicken (Gallus gallus)

Heat shock protein 70 (HSP70) is a predominant member of the HSP family of proteins which play a variety of functions in the cells and are responsible for cytoprotection under stress conditions. In this study, intronless gene of chicken HSP70 was amplified, cloned in E. coli and characterized. The HSP70 gene contains 1,905 bp ORF. Sequence analysis of the HSP70 gene using Mega 4 and DNA STAR softwares showed a high sequence homology among different species indicating that the gene is evolutionarily conserved. Synonymous substitution (dS) in the HSP70 gene was higher than non-synonymous substitution (dN), suggesting that the gene is not under positive selection and that no advantageous mutations had any significant role in its evolutionary adaptation. The predicted Swiss-model of HSP70 protein consisted of 3 α-helices, 19 β-turns, 7 G-turns and 4 hairpins. The G-factor score for the HSP70 protein model was −0.82 for dihedral bonds, −0.05 for covalent bonds and −0.45 overall, which suggest that the model obtained for HSP70 is a reliable one.