Fig 1. Schematic representation of the input forms of GPCR-SAS and the possible outcomes.

The input of GPCR-SAS consists in two main sections: (i) Positions and Sequence: where the user can introduce a position/set of positions and a residue or sequence motif and (ii) Classification, that provides navigable multilevel hierarchical classification of GPCRs in families, branches and various levels of subfamilies according to different implemented schemes.