Investigation of Cyc1 protein structure stability after H53I mutation using computational approaches to improve redox potential.

Abstract Acidithiobacillus ferrooxidans (Af) is an acidophilic bacterium that grows in rigid surroundings and gets its own energy from the oxidation of Fe2+ to Fe3+. These bacteria are involved in the bioleaching process. Cyc1 is a periplasmic protein with a crucial role in electron transportation in the respiratory chain. His53 of the Cyc1 protein, involved in electron transfer to CoxB, was selected for mutation and bioinformatics studies. His53 was substituted by Ile using PyMol software. Molecular dynamics simulations were performed for wild and mutant types of Cyc1 protein. The conformational changes of mutated protein were studied by analyzing RMSD, RMSF, SASA, Rg, H Bond, and DSSP. The results of the RMSF analysis indicated an increase in the flexibility of the ligand in the mutant. Finally, active site instability leads to an increase in the value of E0 at the mutation point and improving electron transfer. On the other, His53 in Cyc1 interconnected to Glu126 in CoxB through the water molecule (W76) and hydrogen bonding. In the H53I mutation, there was a decrease in the distance between H2O 2030, 2033, and isoleucine 53, and subsequently, the distance to the water molecule 76 between the two proteins was reduced and strengthens the hydrogen bond between Cyc1 and CoxB, finally improves electron transfer and the bioleaching process.