A mutation increases the specificity to plant compounds in an insect chemosensory protein

• Published in: Journal of molecular graphics & modelling Vol. 114; p. 108191
• Main Authors: González-González, Angélica, Yañez, Osvaldo, Ballesteros, Gabriel I., Palma-Millanao, Rubén, Figueroa, Christian C., Niemeyer, Hermann M., Ramírez, Claudio C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2022
• Subjects: Chemosensory protein; Docking; Ecological specialization; Molecular dynamics; Tobacco; Molecular dynamics; Docking; Tobacco; Ecological specialization; Chemosensory protein
• ISSN: 1093-3263; 1873-4243
• DOI: 10.1016/j.jmgm.2022.108191

Host plant recognition are highly dependent on chemosensory perception, which involves chemosensory proteins (CSPs) that bind key chemical compounds the host plants. In this work, we hypothesize that two closely related aphid taxa, which differ in diet breadth, also differ in their CSPs. We detected a non-synonymous difference (lysine for asparagine) between M. persicae sensu stricto (Mpp) and the subspecies M. p. nicotianae (Mpn) in the sequence of a CSP (CSP5). We modeled in silico the binding capacity of both CSP5s variants with 163 different potential ligands from their host plants (120 unique from tobacco, 29 unique from peach, and 14 common ligands). After docking analysis with all ligands, we selected the three best ligands for each variant to perform molecular dynamics (tobacco: 2-cyclopentene-1,4-dione, salicylaldehyde, and benzoic acid; peach: phenol, valeric acid, and benzonitrile). The binding energy of the MpnCSP5 model to the studied ligands was, in all cases, lower than with the MppCSP5 model. The ligands from the host plants showed more stable binding with MpnCSP5 than with MppCSP5. This result suggests that the set of CSPs studied among M. persicae s. str. and M. p. nicotianae are very similar, but focusing on the CSP5 protein, we found a single key mutation that increases affinities for host compounds for M. p. nicotianae, which might have contributed to the specialization to tobacco. This study provides new insights into an evolutionary trend toward specificity in a binding protein.
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•A mutation in an insect's chemosensory protein changes the affinity for plant chemicals.•The mutation increased the binding to ligands in the specialized insect protein.•The mutation did not occur at the active site, but 10 Å away from it.