Molecular organization of Conoidean venom toxins. A. Schematic of the precursor sequence for conoidean toxins. Conoidean toxins possess a signal sequence at the ntermini, an intervening pro-region, followed by the mature toxin in single copy. Each gene superfamily is generally characterized by one highly conserved signal sequence, associated in most cases to one cysteine (Cys)-pattern in the mature sequence, and corresponding to several toxin families (such as α, μ, ω, δ) and molecular targets (ion channels or receptors). B. Conotoxin examples. Depicted are the mature toxin sequences, gene superfamily, and molecular targets of well characterized conotoxins.