Cucumber mosaic virus infection leads to mosaic symptoms on a broad range of crop plants. Mutation at positions 129 in the coat protein of virus causes alterations in the severity of symptoms caused by the viral infection. In our investigation, we performed long term molecular dynamics simulations to elucidate the effect of different amino acid substitutes (infectious and non-infectious) at position 129 in the coat protein of Cucumber mosaic virus using various structural parameters. We found that the contagious mutants displayed more flexibility at loops βE-αEF (129-136) and βF-βG loop (155-163) as compared to the non-infectious and native structures. This specific study at the atomic level yields innovative ideas for designing new therapeutic agents against the pathogen, which would further pave the path for researchers to control this devastating plant virus.