Divide, conquer and reconstruct: How to solve the 3D structure of recalcitrant Micro-Exon Gene (MEG) protein from Schistosoma mansoni

0575284 - ÚOCHB 2024 RIV US eng J - Journal Article
Nedvedova, S. - Guilliere, F. - Miele, A. E. - Cantrelle, F. X. - Dvořák, Jan - Walker, O. - Hologne, M.
Divide, conquer and reconstruct: How to solve the 3D structure of recalcitrant Micro-Exon Gene (MEG) protein from Schistosoma mansoni.
PLoS ONE. Roč. 18, č. 8 (2023), č. článku e0289444. ISSN 1932-6203. E-ISSN 1932-6203
Institutional support: RVO:61388963
Keywords : human insulin monomer * NMR stucture * dynamics
OECD category: Biochemistry and molecular biology
Impact factor: 3.7, year: 2022
Method of publishing: Open access
https://doi.org/10.1371/journal.pone.0289444

Micro-Exon Genes are a widespread class of genes known for their high variability, widespread in the genome of parasitic trematodes such as Schistosoma mansoni. In this study, we present a strategy that allowed us to solve the structures of three alternatively spliced isoforms from the Schistoma mansoni MEG 2.1 family for the first time. All isoforms are hydrophobic, intrinsically disordered, and recalcitrant to be expressed in high yield in heterologous hosts. We resorted to the chemical synthesis of shorter pieces, before reconstructing the entire sequence. Here, we show that isoform 1 partially folds in a-helix in the presence of trifluoroethanol while isoform 2 features two rigid elbows, that maintain the peptide as disordered, preventing any structuring. Finally, isoform 3 is dominated by the signal peptide, which folds into a-helix. We demonstrated that combining biophysical techniques, like circular dichroism and nuclear magnetic resonance at natural abundance, with in silico molecular dynamics simulation for isoform 1 only, was the key to solve the structure of MEG 2.1. Our results provide a crucial piece to the puzzle of this elusive and highly variable class of proteins.
Permanent Link: https://hdl.handle.net/11104/0345056