Blocks Kv11/ERG potassium channels. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Has the CSalpha/beta fold, which comprises one or two short alpha helices connected to anti-parallel beta-sheets stabilized by three or four disulfide bonds. Belongs to the ergtoxin family. Gamma-KTx 1 subfamily.