New binding site on common molecular scaffold provides HERG channel specificity of scorpion toxin BeKm-1.
Korolkova, Y.V., Bocharov, E.V., Angelo, K., Maslennikov, I.V., Grinenko, O.V., Lipkin, A.V., Nosyreva, E.D., Pluzhnikov, K.A., Olesen, S.P., Arseniev, A.S., Grishin, E.V.(2002) J Biol Chem 277: 43104-43109
- PubMed: 12151390
- DOI: https://doi.org/10.1074/jbc.M204083200
- Primary Citation of Related Structures:
1J5J, 1LGL - PubMed Abstract:
The scorpion toxin BeKm-1 is unique among a variety of known short scorpion toxins affecting potassium channels in its selective action on ether-a-go-go-related gene (ERG)-type channels. BeKm-1 shares the common molecular scaffold with other short scorpion toxins. The toxin spatial structure resolved by NMR consists of a short alpha-helix and a triple-stranded antiparallel beta-sheet. By toxin mutagenesis study we identified the residues that are important for the binding of BeKm-1 to the human ERG K+ (HERG) channel. The most critical residues (Tyr-11, Lys-18, Arg-20, Lys-23) are located in the alpha-helix and following loop whereas the "traditional" functional site of other short scorpion toxins is formed by residues from the beta-sheet. Thus the unique location of the binding site of BeKm-1 provides its specificity toward the HERG channel.
Organizational Affiliation:
Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, 117997 Moscow, Russia. july@ibch.ru