Microcins are low-molecular weight, highly stable, ribosomally produced, bacterial inhibitory molecules involved in competitive research. Microcin J25 consists of 21 amino acids and has a lasso-like structure. The first step is bacteria binding to the ion receptor of FhuA on the bacterial surface. In this study, molecular dynamics simulation was implemented to study the binding mechanism of MJ25 and three mutants, to find the changing of individual amino acids in the β-hair region of MJ25. The binding-free energy calculation was subjected to MJ25 and FhuA. In addition, computational mutation analysis was revealed for association between MJ25 and FhuA. However, we found that the mutating 12th amino acid of the β-hair region into histidine is extremely important for the binding of MJ25 to FhuA. In addition, the number of hydrogen bonds is essential for binding of MJ25 to FhuA. The overall results show that the key guiding significance is improving the sterilizing efficiency of MJ25 and the drug design of MJ25.Communicated by Ramaswamy H. Sarma.
Keywords: FhuA; MD simulation; Microcin J25; binding free-energy calculation; β-hair region.