Baroni F, Gallo M, Pazzagli L, Luti S, Baccelli I, Spisni A, Pertinhez TA. A mechanistic model may explain the dissimilar biological efficiency of the fungal elicitors cerato-platanin and cerato-populin.
Biochim Biophys Acta Gen Subj 2021;
1865:129843. [PMID:
33444726 DOI:
10.1016/j.bbagen.2021.129843]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/17/2020] [Accepted: 01/08/2021] [Indexed: 11/19/2022]
Abstract
Among their various functions, the members of the cerato-platanin family can stimulate plants' defense responses and induce resistance against microbial pathogens. Recent results suggest that conserved loops, also involved in chitin binding, might be a structural motif central for their eliciting activity. Here, we focus on cerato-platanin and its orthologous cerato-populin, searching for a rationale of their diverse efficiency to elicit plants' defense and to interact with oligosaccharides. A 3D model of cerato-populin has been generated by homology modeling using the NMR-derived cerato-platanin structure as template, and it has been validated by fitting with residual dipolar couplings. Loops β1-β2 and β2-β3 have been indicated as important for some CPPs members to express their biological function. When compared to cerato-platanin, in cerato-populin they present two mutations and an insertion that significantly modify their electrostatic surface. NMR relaxation experiments point to a reduced conformational plasticity of cerato-populin loops with respect to the ones of cerato-platanin. The different electrostatic surface of the loops combined with a distinct network of intra-molecular interactions are expected to be factors that, by leading to a diverse spatial organization and dissimilar collective motions, can regulate the eliciting efficacy of the two proteins and their affinity for oligosaccharides.
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