Ligand binding mode of GABAA receptor-associated protein

The gamma-aminobutyric acid type A (GABA(A)) receptor-associated protein is a versatile adaptor protein playing an important role in intracellular vesicle trafficking, particularly in neuronal cells. We present the X-ray structure of the soluble form of human GABA(A) receptor-associated protein complexed with a high-affinity synthetic peptide at 1.3 A resolution. The data shed light on the probable binding modes of key interaction partners, including the GABA(A) receptor and the cysteine protease Atg4. The resulting models provide a structural background for further investigation of the unique biological properties of this protein.