Emilie Müller, Celeste Menuet Hackney, Lars Ellgaard, Jens Preben Morth
Acta crystallographica. Section F, Structural biology communications 2023 Sep 01Marine cone snails produce a wealth of peptide toxins (conotoxins) that bind their molecular targets with high selectivity and potency. Therefore, conotoxins constitute valuable biomolecular tools with a variety of biomedical purposes. The Mu8.1 conotoxin from Conus mucronatus is the founding member of the newly identified saposin-like conotoxin class of conotoxins and has been shown to target Cav2.3, a voltage-gated calcium channel. Two crystal structures have recently been determined of Mu8.1 at 2.3 and 2.1 Å resolution. Here, a high-resolution crystal structure of Mu8.1 was determined at 1.67 Å resolution in the high-symmetry space group I4122. The asymmetric unit contained one molecule, with a symmetry-related molecule generating a dimer equivalent to that observed in the two previously determined structures. The high resolution allows a detailed atomic analysis of a water-filled cavity buried at the dimer interface, revealing a tightly coordinated network of waters that shield a lysine residue (Lys55) with a predicted unusually low side-chain pKa value. These findings are discussed in terms of a potential functional role of Lys55 in target interaction. open access.
Emilie Müller, Celeste Menuet Hackney, Lars Ellgaard, Jens Preben Morth. High-resolution crystal structure of the Mu8.1 conotoxin from Conus mucronatus. Acta crystallographica. Section F, Structural biology communications. 2023 Sep 01;79(Pt 9):240-246
PMID: 37642664
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