Abstract:
Viral synergism in plants has been characterized by the intensification of infection caused by
coinfecting viruses, which has a significant negative impact on plant health and crop
productivity by exacerbating the disease symptoms. The goal of the study was to determine the
protein-protein interactions between two economically significant viruses that co-infect cassava
plants, Cassava brown streak virus (CBSV, an Ipomovirus) and Cassava mosaic virus (CMV, a
begomovirus). An in-silico approach has been used to elucidate the nature of the co-infection
between these two viruses. The methodology focuses on predicting the protein structures using
trRosetta, which are then validated by Errat and Ramachandran plots. The proteins from both
viruses are docked using ClusPro, and the interacting residues of the docked complexes are
highlighted via PDBsum. To further confirm the stability of these complexes, we have
conducted 50 ns molecular dynamic simulations on the complexes that displayed the strongest
affinity. A well refined protein models are obtained from trRosetta, with the majority scoring
above 85% in the ERRAT assessment, and over 90% of the amino acid residues fall within the
allowed region of the Ramachandran plot, indicating their favorable conformations. The
docking results indicate that the V2 and MP proteins, out of all the CMV proteins, are crucial
to the infection process and interact strongly with all CBSV proteins. Our findings reveal
synergistic interactions between CMV and CBSV at the protein level. This information could
be helpful in developing effective disease management strategies aimed at controlling cassava
disease and developing durable resistance against these economically important viruses.
