This family consists of several Hadronyche versuta (Blue mountains funnel-web spider) specific omega-atracotoxin proteins. Omega-Atracotoxin-Hv1a is an insect-specific neurotoxin whose phylogenetic specificity derives from its ability to antagonise insect, but not vertebrate, voltage-gated calcium channels. Two spatially proximal residues, Asn(27) and Arg(35), form a contiguous molecular surface that is essential for toxin activity. It has been proposed that this surface of the beta-hairpin is a key site for interaction of the toxin with insect calcium channels [1].

1: Functional significance of the beta hairpin in the insecticidal neurotoxin omega-atracotoxin-Hv1a. Tedford HW, Fletcher JI, King GF; J Biol Chem 2001;276:26568-26576. PMID:11313356

2: The structure of a novel insecticidal neurotoxin, omega-atracotoxin-HV1, from the venom of an Australian funnel web spider. Fletcher JI, Smith R, O'Donoghue SI, Nilges M, Connor M, Howden ME, Christie MJ, King GF; Nat Struct Biol 1997;4:559-566. PMID:9228949

3: Structure-function studies of omega-atracotoxin, a potent antagonist of insect voltage-gated calcium channels. Wang X, Smith R, Fletcher JI, Wilson H, Wood CJ, Howden ME, King GF; Eur J Biochem 1999;264:488-494. PMID:10491095