sentences:  Evidence indicates that these residues probably do not interact with antagonists, but would rather indirectly influence the overall conformation of the antagonist binding site.The residue Gln165 (TM4) has also proven to be meaningful for the binding of several non-peptide antagonists, possibly through the formation of a hydrogen bond.Phe268 and Tyr287 have been proposed as possible contact points for both agonist and antagonist binding domains.