1RJI

Solution Structure of BmKX, a novel potassium channel blocker from the Chinese Scorpion Buthus martensi Karsch

Summary for 1RJI

• Entry DOI: 10.2210/pdb1rji/pdb
• NMR Information: BMRB: 6037
• Descriptor: potassium channel toxin KX (1 entity in total)
• Functional Keywords: 3-10 helix, beta sheet, toxin
• Cellular location: Secreted: Q7Z0H4
• Total number of polymer chains: 1
• Total formula weight: 3333.88

Authors

Cai, Z.,Wu, J.,Xu, Y.,Wang, C.-G.,Chi, C.-W.,Shi, Y. (deposition date: 2003-11-19, release date: 2003-12-09, Last modification date: 2024-10-23)

Primary citation

Wang, C.-G.,Cai, Z.,Lu, W.,Wu, J.,Xu, Y.,Shi, Y.,Chi, C.-W.
A novel short-chain peptide BmKX from the Chinese scorpion Buthus martensi karsch, sequencing, gene cloning and structure determination
Toxicon, 45:309-319, 2005

PubMed Abstract: Scorpion venom is a rich source of bioactive peptides. From the venom of Chinese scorpion Buthus martensi Karsch (BmK), a novel short chain peptide BmKX of 31-amino acid residues was purified, and its amino acid sequence and gene structure were determined. The gene of BmKX was composed of two exons interrupted by an 86-bp intron at the codon-7 upstream of the mature peptide. Although its gene structure is similar to those of other known scorpion toxins, its amino acid sequence, especially the cysteine framework, is different from those of all other known subfamilies of short-chain scorpion toxins. The solution structure of BmKX, determined with two-dimensional NMR spectroscopy, shows that BmKX also forms a typical cysteine-stabilized alpha/beta scaffold adopted by most short-chain scorpion toxins, consisting of a short 3(10)-helix and a two-stranded antiparallel beta-sheet, and the short N-terminal segment forms a pseudo-strand of the beta-sheet. However, the orientation between the helix and the beta-sheet is significantly different from the others, which might be the reason for its unique but still unclear physiological function.

PubMed: 15683869
DOI: 10.1016/j.toxicon.2004.11.014

Experimental method

SOLUTION NMR