Fusion protein amino acids 861-912 of rat GABABR2 (also known as gammaaminobutyric acid type B receptor subunit 2, GABA-B receptor 2, Gb2, Gprotein coupled receptor 51 or GPR51, accession number NP_113990) Mouse: 100% identity (52/52 amino acids identical) Human: 100% identity (52/52 amino acids identical) <12% identity with GABABR1