The Haemonchus contortus UNC-49B subunit possesses the residues required for GABA sensitivity in homomeric and heteromeric channels

► Residues important for GABAA receptor sensitivity are largely conserved between parasitic nematodes and mammals. ► Residues affecting GABA sensitivity were found only on the Hco-UNC-49B subunit. ► Met170 in the H. contortus UNC-49 receptor is associated with slightly higher GABA sensitivity.